TY  - THES
A1  - Junold, Konstantin
T1  - Synthese, Struktur und Eigenschaften neuer höherkoordinierter Silicium(II)- und Silicium(IV)-Komplexe
T1  - Synthesis, structure, and reactivity of novel higher-coordinate silicon(II) and silicon(IV) complexes
N2  - Die vorliegende Arbeit stellt einen Beitrag zur Chemie des höherkoordinierten Siliciums dar. Im Vordergrund standen die Synthese und Charakterisierung neuer neutraler penta- und hexakoordinierter Silicium(IV)-Komplexe sowie die Synthese, Charakterisierung und Untersuchung der Reaktivität eines neuartigen Donor-stabilisierten Silylens.
N2  - This thesis is a contribution to the chemistry of higher-coordinate silicon. The main focus of this work was the synthesis and characterization of novel neutral five- and six-coordinate silicon(IV) complexes as well as the synthesis, characterization, and reactivity of a novel donor-stabilized silylene.
KW  - Siliciumkomplexe
KW  - Silicium(IV)-Komplexe
KW  - Silicium(II)-Komplexe
KW  - Silicon(IV) Complexes
KW  - Silicon(II) Complexes
KW  - Höherkoordinierte Verbdinungen
KW  - Higher-coordinate Compounds
KW  - Pentakoordination
KW  - Hypervalentes Molekül
KW  - Silylen
KW  - Anorganische Chemie
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-104848
ER  - 
TY  - THES
A1  - Arnold, Thomas
T1  - Reaktivität von Disilamolybdänocenophanen
T1  - Reactivity of Disilamolybdenocenophanes
N2  - Es wird die Reaktivität eines hochgespannten und reaktiven [1],[1]-Disilamolybdänocenophanes gegenüber ungesättigten Substraten, E–H Funktionen und E–E-Bindungen untersucht. Die Produkte wurden mittels spektroskopischer Methoden in Lösung sowie im Festkörper identifiziert und charakterisiert. Weiterhin wird die Reaktivität eines [2]-Disilamolybdänocenophanes ebenfalls gegenüber ungesättigten Substraten und E–E-Bindungen sowie gegenüber Pt(0)-Verbindungen erforscht. Die erhaltenen Komplexe wurden sowohl im Festkörper, als auch in Lösung spektroskopisch untersucht und charakterisiert.
N2  - The reactivity of a highly strained and reactive [1],[1]-Disilamolybdenocenophane towards unsaturated substrates, E–H- and E–E-bonds is investigated. The products were identified and characterized by spectroscopic methods in solution and in solid state by X-ray diffraction. Furthermore the reactivity of a [2]-Disilamolybdenocenophane towards unsaturated substrates and E–E-bonds as well as towards Pt(0) compounds is studied. The obtained complexes were characterized in solution by NMR spectroscopy and in the solid state by X-ray diffraction.
KW  - Metallocene
KW  - Molybdän
KW  - Silanderivate
KW  - Reaktivität
KW  - ansa-Metallocene
KW  - Metallocenophane
KW  - metallocenes
KW  - molybdenum
KW  - silicon
KW  - reactivity
KW  - inorganic chemistry
KW  - ansa-metallocenes
KW  - metallocenophanes
KW  - Silicium
KW  - Anorganische Chemie
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-83865
ER  - 
TY  - THES
A1  - Bissinger, Philipp
T1  - Synthese, Struktur und Reaktivität Basen-stabilisierter Borane und Diborene
T1  - Synthesis, Structure and Reactivity of Base Stabilized Boranes and Diborenes
N2  - Umsetzungen N-heterocyclischer Carbene mit Boranen führen zur Bildung von „Lewis-Säure-Base-Addukten“. In Abhängigkeit des Substitutionsmusters der eingesetzten Borane bzw. Carbene eignen sich die erhaltenen Addukte als Ausgangsverbindungen zur Realisierung verschiedener Strukturmotive. Mit geeigneten Übergangsmetallfragmenten gelingt die Darstellung von sigma-Boran-Komplexen bzw. Basen-stabilisierter Boryl-Komplexe, welche mittels spektroskopischer Methoden sowohl im Festkörper, als auch in Lösung untersucht wurden. Ebenfalls gelingt die Synthese Basen-stabilisierter Borirane und einer tetraedrischen Borid-Spezies. Zudem wird ein selektiver Zugang zu Basen-stabilisierten Diborenen entwickelt, wobei deren Bindungssituation und Reaktivität im Detail diskutiert wird. So kann das B=B-Fragment in polymere Spezies eingebunden werden oder als Ligand an Übergangsmetalle koordinieren.
N2  - Reaction of boranes with N-heterocyclic carbenes results in the formation of „Lewis-acid-base-adducts“. Depending on the substitution pattern of the boranes and carbenes, respectively, these adducts represent versatile starting materials for the realization of a diversity of different structural motifs. Treatment with suitable transition-metal fragments for instance afforded sigma-borane complexes and base-stabilized boryl complexes. These species are characterized in the solid state by X-ray diffraction, as well as by spectroscopy in solution. In addition, the synthesis of base-stabilized boriranes and a tetrahedral boride species is described. Moreover, a selective approach for the synthesis of base-stabilized diborenes is developed and their bonding situation and reactivity is studied in detail. Thus, the B=B moiety can be incorporated into polymeric structures or act as a ligand in the coordination sphere of transition-metals.
KW  - Borane
KW  - Carbene
KW  - Lumineszenz
KW  - Polymere
KW  - boron
KW  - inorganic chemistry
KW  - carbenes
KW  - luminescence
KW  - polymers
KW  - Bor
KW  - Anorganische Chemie
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-79144
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Saad, S. M.
T1  - Silylation of cellulose
N2  - Ethane-l:2-diol and propane-l:3-diol reaet with 1: 1:3:3-tetramethyl-l:3-dichlorodisiloxane forming the corresponding rings. However, no ring compounds could be traced tbrough the reaction between butane-l :4-diol, glycerol and the dichlorodisiloxane respectively, where only polymeric compounds are formed. The silylation products of the di- and trihydroxy alcohols, as model compounds, has confirmed that the ring formation during silylation of cellulose with dichlorodisiloxane is uncertain.
KW  - Anorganische Chemie
Y1  - 1977
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78368
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Bentlage, Anke
A1  - Towart, Robertson
A1  - Möller, Eike
T1  - Sila-pharmaca, XXV. Sila-analogues of nifedipine-like dialkyl 2,6-dimethyl-4-aryl-1,4 dihydropyridine-3,5-dicarboxylates, III
N2  - IS neue C/Si-Analogenpaare (C-Verbindungen und sila- bzw. disila-substituierte Derivate), die sich strukturell vom Nifedipin ableiten, wurden synthetisiert. Diese und einige weitere C/Si-Paare wurden hinsichtlich ihrer physikochemischen und pharmakologischen Eigenschaften vergleichend untersucht. Mittels reversed-phase-Dünnschichtchromatographie wurde gezeigt, daß die Sila- bzw. Disila-Analoga lipophiler sind als die entsprechenden C-Verbindungen. Bezüglich der spasmolytischen in vitra-Aktivitäten zeigen die Si-Verbindungen in erster Näherung ähnliche Struktur-Wirkungs-Beziehungen wie ihre Carba-Analoga. Dagegen konnten hinsichtlich der ill vlva-Effekte (cardiovasculäre und antihypertensive Aktivität) in einigen Fällen große Unterschiede nachgewiesen werden.
N2  - 15 new C/Si-analogue pairs (C-compounds and sila- or disila-substituted derivatives, respectively), which are structurally related to nifedipine, have been synthesized. These and some further C/Si-pairs have been investigated comparatively with respect to their physicochemical and pharmacological properties. Using reversed-phase thin-layer chromatography it was shown that both the sila- and disila-analogues are more Iipophilic than the corresponding C-compounds. With respect to the in vitra spasmolytic potencies the Si-compounds show approximately similar structure-activity relationships to their carba-analogues. However, in some cases marked differences in in vivo effects (cardiovascular and antihypertensive activity) could be demonstrated.
KW  - Anorganische Chemie
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78357
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Wuttke, F.
A1  - Henke, H.
T1  - Zur Stereochemie der mikrobiellen Reduktion von rac-Acetyl( t-butyl)methylphenylsilan mit Trigonopsis variabilis (DSM 70714) und Corynebacterium dioxydans (ATCC 21766): Aufklärung der absoluten Konfiguration der Biotransformationsprodukte (SiR,CR)- und ( SiS ,CR)-t-Butyl( 1-hydroxyethyl)methylphenylsilan
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64176
ER  - 
TY  - THES
A1  - Damme, Alexander
T1  - Reaktivität von Diboranen(4) gegenüber metallischen und nicht-metallischen Lewis-Basen
T1  - Reactivity of Diboranes(4) towards metal and non-metal Lewis-Bases
N2  - Die Reaktivität von Diboranen(4) (1,2-Dihalogendiboranen(4)) gegenüber von metallischen und nicht-metallischen Lewis-Basen wurde untersucht. Die Ergebnisse zeigen, dass die oxidative Addition einer Bor-Halogen-Bindung an ein Platin(0)-Komplex selektiv verläuft und in trans-Diboran(4)yl-Bisphosphan-Platin-Komplexen resultiert. Bei Verwendung von 1,2-Dihalogen-1,2-diaryldiboranen(4) findet sich in den korrespondierenden trans-Diboran(4)yl-Platin-Komplexen eine dative Bindung des Platin-Zentralatoms zum entfernten zweiten Bor-Atom, welche sowohl in Lösung als auch im Festkörper beobachtet wird. Die erhaltenen trans-Diboran(4)yl-Komplexe wurden auf ihre Reaktivität untersucht, hierbei konnte erstmals durch Reduktion ein Diboren-Platin-Komplex synthetisiert werden. Die Untersuchung der Reaktivität von nicht-metallischen Lewis-Basen ergab eine Reihe von sp2-sp3-Diboranen an die entweder PEt3 oder PMeCy2 koordiniert ist. In Abhängigkeit des sterischen Anspruches finden sich zwei Isomere mit 1,2- und 1,1'-Anordnung der Halogene. Die 1,2-Isomere zeigen hierbei im Festkörper eine Bor-Halogen-Bor-Brücke mit einer dativen Halogen-Bor-Bindung zwischen dem Halogen und dem sp2-Borzentrum.
N2  - The reactivity of diboranes(4) (1,2-dihalodiboranes(4)) towards metal and non-metal Lewis-Bases was examined. The results have shown that the oxidative addition of the boron-halide bond to a platinum center results exclusively in the corresponding trans-diboran(4)yl-bisphosphane-platinum complexes. Using 1,2-dihalo-1,2-diaryldiboranes(4) for the oxidative addition to platinum(0) reveals the corresponding trans-diboran(4)yl platinum complexes with a dative platinum boron bond to the remoted boron atom of the diboran(4)yl ligand. This structural motive can be found in solution as well as in the solid state. The reactivity of the obtained trans-diboran(4)yl-platinum complexes were investigated. Here a diborene-platinum complex was synthesized for the first time by reduction chemistry. The investigation of the reactivity of diboranes(4) toward non-metal Lewis-Bases, such as PEt3 or PMeCy2, lead to sequence of sp2–sp3 phosphine adducts of diboranes. Depending on the steric demand of the used phosphanes two isomers were identified and characterized. The isomers distinguish between the 1,2- and 1,1’-substitutions pattern of the halides, which are formed by a 1,2-rearrengment, which is favoured for the bulky PMeCy2. In the solid state the 1,2-isomers are showing a boron-halide-boron bridge and a rare dative boron-halide bonding interaction to the sp2 boron center.
KW  - Diborane
KW  - Übergangsmetallkomplexe
KW  - Lewis-Base
KW  - Diboran(4)
KW  - Diboren
KW  - Diboran(4)yl-Platin-Komplex
KW  - Übergangsmetallkomplexe
KW  - sp2-sp3 Diborane
KW  - Bor
KW  - Platin
KW  - Anorganische Chemie
KW  - Übergangsmetall
KW  - diborane(4)
KW  - diboren
KW  - diboran(4)yl platinum complex
KW  - transition metal complex
KW  - sp2-sp3 diboranes
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-77750
ER  - 
TY  - JOUR
A1  - Braunschweig, Holger
A1  - Damme, Alexander
T1  - 1,2-Bis(dimethylamino)-1,2-bis(2,4,6-triisopropylphenyl)diborane(4)
N2  - In the molecular structure of the title compound, C34H58B2N2, each B atom of the diborane(4) is connected to one dimethylamino group and one Tip ligand (Tip = 2,4,6-triisopropylphenyl). These findings indicate that the increased steric demand of the Tip groups exerts influence solely on the B—B separation but not on the overall geometry of the title compound.
KW  - Anorganische Chemie
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67639
ER  - 
TY  - JOUR
A1  - Braunschweig, Holger
A1  - Dewhurst, Rian D.
A1  - Schwab, Katrin
A1  - Wagner, Katharina
T1  - {N ',N ''-Bis[2,6-bis(1-methylethyl)phenyl]-N,N-dimethylguanidinato-kappa N-2 ',N ''}dibromidoborane
N2  - In the molecular structure of the title compound, C27H40N3BBr2, the B atom is connected to two bromide substituents and a guanidinate scaffold, forming a four– membered ring. An aryl group is connected to each N atom in the ring that contains two isopropyl groups in positions 2 and 6.
KW  - Anorganische Chemie
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67622
ER  - 
TY  - JOUR
A1  - Werner, H.
A1  - Leonhard, K.
A1  - Burschka, Christian
T1  - Basische Metalle: IX. Synthese und Kristallstruktur von C\(_5\)H\(_5\)Co(PMe\(_3\))CS\(_2\) : Reaktionen zu zweikernkomplexen mit Co(SCS)Cr- und Co(SCS)Mn-Brückenbindungen
T1  - Basic metals.  IX.  Synthesis and crystal structure of C\(_5\)H\(_5\)Co(PMe\(_3\))CS\(_2\).  Reactions to binuclear complexes with Co(SCS)Cr and Co(SCS)Mn bridging compounds.
N2  - Durch Reaktion von C\(_5\)H\(_5\)Co(PMe\(_3\))\(_2\) (I) oder des Hetero-Zweikernkomplexes C\(_5\)H\(_5\)(PMe\(_3\))Co(CO)\(_2\)Mn(CO)C\(_3\)H .. Me (III) mit CS\(_2\) entsteht in praktisch quantitativer Ausbeute C\(_5\)H\(_5\)Co(PMe\(_3\))CS\(_2\) (IV). Die Kristallstruktur zeigt, dass der Carbondisulfid-Ligal'ld iiber Kohlenstoff und ein Schwefelatom (S(2)) dihaptogebunden vorliegt (Co-C = 1.89, Co-S(2) = 2.24 A, S(2)-C-S(1) = 141.2°). Die beiden C-S-AbsUinde in IV (C-S(2) = 1.68, C-S(l) = 1.60 A) sind gegenliber dem C-S-Abstand in freiem CS\(_2\) (1.554 A) aufgeweitet, was in Einklang mit dem aus spektroskopischen Daten zu folgernden starken 1T-Akzeptorcharakter von h\(^2\)-CS\(_2\) steht. IV reagiert mit Cr(CO)\(_5\)THF und C\(_5\)H\(_5\)Mn(CO)\(_2\)THF zu den Komplexen C\(_5\)H\(_5\)(PMe\(_3\))Co(SCS)Cr(CO)\(_5\) (V) bzw. C\(_5\)H\(_5\)(PMe\(_3\))Co(SCS)Mn(CO)\(_2\)C\(_5\)H\(_5\) (VI), in den en das in IV nicht am Cobalt gebundene Schwefelatom S(l) als Koordinationspartner gegenüber den 16-Elektronen-Fragmenten Cr(CO)\(_5\) und Mn(CO)\(_2\)C\(_5\)H\(_5\) fungierl. Die spektroskopischen Daten von IV, V und VI werden diskutiert.
N2  - C\(_5\)H\(_5\)Co(PMe\(_3\))CS\(_2\) (IV) is formed in practically quantitative yield in the reaction of C\(_5\)H\(_5\)Co(PMe\(_3\))\(_2\) (I) or the heterobinuclear complex C\(_5\)H\(_5\)(PMe\(_3\))Co(CO)\(_2\)Mn(CO)C\(_3\)H .. Me (III) with CS\(_2\). The crystal structure shows that the carbon disulfide bonds as a dihapto ligand through the carbon and one sulfur atom (S(2)) (Co-C = 1.89, Co-S(2) = 2.24 ft., S(2)-C-S(1) = 141.2°). The two C-S bond lengths in IV (C-S(2) = 1.68, C-S(l) = 1.60 A) are greater than in free CS\(_2\) (1.554 A) which is in agreement with the strong 7T-acceptor character of h\(^2\)-CS\(_2\) as shown in the spectroscopic data. IV reacts with Cr(CO)\(_5\)THF and C\(_5\)H\(_5\)Mn(CO)\(_2\)THF to give the complexes C\(_5\)H\(_5\)(PMe\(_3\))Co(SCS)Cr(CO)\(_5\) (V) and C\(_5\)H\(_5\)(PMe\(_3\))Co(SCS)Mn(CO)\(_2\)C\(_5\)H\(_5\) (VI) respectively, in which the sulfur atom S(l) that is not bound to cobalt coordinates to the 16-electron fragments Cr(CO)\(_5\) and Mn(CO)\(_2\)C\(_5\)H\(_5\). The spectroscopic data of IV, V and VI are discussed.
KW  - Anorganische Chemie
Y1  - 1978
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-70444
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Mühleisen, M.
T1  - Bis[benzilato(2-)-O\(^1\),O\(^2\)][2-(dimethylammonio)ethoxy]silicate: synthesis and structural characterization of a zwitterionic \(\lambda^5\)Si-silicate with a SiO\(_5\) framework
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64400
ER  - 
TY  - JOUR
A1  - Mühleisen, M.
A1  - Tacke, Reinhold
T1  - meso-[1,4-Piperaziniumdiylbis(methylene)]bis{bis[2-methyllactato(2-)-O1,O2]silicate} octahydrate: synthesis and crystal structure analysis of a zwitterionic dispirocyclic \(\lambda^5\)Si,\(\lambda^5\)Si'-disilicate
N2  - The zwitterionic dispirocyclic \(\lambda^5\)Si,\(\lambda^5\)Si'-disilicate meso-[1 ,4-piperaziniumdiylbis( methylene)]bis{ bis[ 2-methyllactato(2-)-O\(^1\),O\(^2\)]silicate} octahydrate (6-8H\(_2\)O) was synthesized by reaction of 1,4-bis[(trimethoxysilyl}methyl] piperazine (8) with 2-methyllactic acid (molar ratio 1:4) in water/acetone (yield 82%). The molecular dinuclear silicon(IV) complex 6 contains two pentacoordinate (formally negatively charged) silicon atoms and two tetracoordinate (formally positively charged) nitrogen atoms. The crystal structure of 6•8H20 was studied by X-ray diffraction.
KW  - Anorganische Chemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64396
ER  - 
TY  - JOUR
A1  - Mühleisen, M.
A1  - Tacke, Reinhold
T1  - Twofold deprotonated citric acid as a bidentate ligand of pentacoordinate silicon: synthesis and structural characterization of the zwitterionic \(\lambda_5\)Si-spirosilicate bis[citrato(2-)-O\(^3\),O\(^4\)][(dimethylammonio)methyl]silicate hydrate
N2  - The zwitterionic \(\lambda_5\) Si-spirosilicate bis[ citrato(2-)-0\(^3\) ,0\(^4\) )[ ( dimethylammonio) methyl]silicate (4) was synthesized by reaction of (MeO)\(_3\)SiCH\(_2\)NMe\(_2\) (3) with citric acid (molar ratio 1 :2) in acetonitrile at room temperature and isolated, after crystallization from water, as the hydrate 4 · H\(_2\)O (yield 81 %). The crystal structure of 4 · H\(_2\)O was studied by single-crystal X-ray diffraction. The alcoxide oxygen atoms and central carboxylate oxygen atoms of two citrato(2-) ligands and one carbon atom coordinate to the silicon atom of 4 · H\(_2\)O. The coordination polyhedron around the pentacoordinate silicon atom (SiO\(_4\)C framework) can be described as a distorted trigonal bipyramid, the two carboxylate oxygen atoms occupying the axial sites. The \(\lambda_5\) Si~silicon(IV) complex 4 also exists in solution (DMSO, H\(_2\)O).
KW  - Anorganische Chemie
KW  - Silicon
KW  - pentacoordinate
KW  - Lambda5Si-Spirosilicate
KW  - zwitterionic
KW  - Citrato(2-)-03
KW  - 04ligand
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64388
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Mühleisen, M.
T1  - Hexacoordinate silicon in a compound with an F\(_5\)SiC unit
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64378
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Mühleisen, M.
T1  - Hexakoordiniertes Silicium in einer molekularen Verbindung mit einer F\(_5\)SiC-Einheit
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64365
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Mühleisen, M.
A1  - Jones, P. G.
T1  - The first zwitterionic, optically active disilicate with pentacoordinate silicon
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64358
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Mühleisen, M.
A1  - Jones, P. G.
T1  - Das erste zwitterionische, optisch aktive Disilicat mit pentakoordiniertem Silicium
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64343
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Lopez-Mras, A.
A1  - Jones, P. G.
T1  - Syntheses, crystal structure analyses, and NMR studies of [2-(dimethylammonio)phenyl]bis[glycolato(2-)-O1,O2]silicate and related zwitterionic spirocyclic \(\lambda_5\)Si-silicates
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64339
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Sperlich, J.
A1  - Becker, B.
T1  - Bis[2,3-naphthalenediolato(2-)](pyrrolidinio-methyl)germanate-tetartoacetonitrile, the first zwitterionic \(\lambda_5\)-germanate: synthesis and crystal structure analysis
N2  - The zwitterionic spirocyclic \(\lambda_5\)-germanate bis(2,3-naphthalenediolato( 2-)](pyrrolidiniomethyl)germanate (8) was synthesized and the crystal structure of its tetartoacetonitrile solvate 8 · 1/4 CH\(_3\)CN studied by single-crystal X-ray diffraction. Compound 8 was prepared by reaction of (MeO)\(_3\)GeCH\(_2\)NC\(_4\)H\(_8\) (11; NC\(_4\)H\(_8\) = pyrrolidino) with two equivalents of 2,3-naphthalenediol (isolated as 8 · 1/4 CH\(_3\)CN; yield 92%). The coordination polyhedron around the pentacoordi- naphthalenediolatonate germanium atom of 8 · 1/4 CH\(_3\)CN can be described as a strongly distorted trigonal bipyramid (the structure is displaced by 38.9% from the ideal trigonal bipyrarnid towards the ideal square pyramid), the carbon atom occupying an equatorial position. In the crystal lattice of 8 · 1/4 CH\(_3\)CN, the zwitterions form intermolecular N-H ... o hydrogen bonds leading to the formation of dimers. 1H- and \(^{13}\C-NMR studies revealed that 8 also exists in solution ([D\(_6\)]DMSO).
KW  - Anorganische Chemie
KW  - Lambda5-Germanate
KW  - zwitterionic
KW  - Germanium
KW  - pentacoordinate
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64329
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Wagner, S. A.
A1  - Sperlich, J.
T1  - Synthese von (-)-(Acetoxymethyl)(hydroxy-methyl)methyl(phenyl)german [(-)-MePhGe(CH\(_2\)OAc)(CH\(_2\)OH)] durch eine Esterase-katalysierte Umesterung: Die erste enzymatische Synthese eines optisch aktiven Germans
N2  - No abstract available.
KW  - Anorganische Chemie
KW  - Germane
KW  - optically active
KW  - Biotransformation
KW  - stereoselective Transesterification
KW  - enzymatic
KW  - Porcine liver esterase
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64310
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Pikies, J.
A1  - Wiesenberger, F.
A1  - Ernst, L.
A1  - Schomburg, D.
A1  - Waelbroeck, M.
A1  - Christophe, J.
A1  - Lambrecht, G.
A1  - Gross, J.
A1  - Mutschler, E.
T1  - Sila-biperiden und endo-Sila-biperiden: Synthesen, Kristallstrukturen und antimuscarinische Eigenschaften
N2  - Starting from trichloro(vinyl)silane (Cl\(_3\)SiCH=CH\(_2\)), the musearinic antagonists sila-biperiden [rac-(SiRS,C2SR>-ao-2] and endosila- biperiden [rac-(SiRS,C2SR)-endo-2] were prepared by a seven-step synthesis. Both silanols are configurationally stableininert organic solvents but undergo slow epimerization in aqueous solution (pH 7.4, 32°C) by inversion of the configuration at the silicon atom. The relative configurations of sila-biperiden and endo-sila-biperiden were detennined by single-crystal X-ray diffraction. Both compounds form intennolecular 0-H · · · N hydrogen bonds in the crystal leading to the fonnation of centrosymmetric dimers (sila-biperiden) and infinite chains (endo-sila-biperiden), respectively. Sila-biperiden is a silicon analogue (C/Si exchange) of the antiparkinsonian drug biperiden [rac-(CRS/C2SR}-exo-1]. In functional phannacological experiments, as well as in radioligand competition studies, biperiden, sila-biperiden and endo-sila-biperiden behaved as simple competitive antagonists at muscarinic Ml-, M2-, M3- and M4-receptors. The three compounds displayed the highest affinity for Ml-receptors (pA\(_2\) values: 8.72-8.80; pK\(_i\) values: 8.8-9.1), intermediate affinity for M4- and M3-receptors, and lowest affinity for M2-receptors (pA\(_2\) values: 7.57-7.79; pK\(_i\) values: 7.7-7.8). The affinity profile (Ml >. M4 > M3 > M2) of biperiden, sila-biperiden and endo-sila-biperiden is qualitatively similar to that of the M1-selective muscarinic antagonist pirenzepine. The antimuscarinic properlies of the C/Si analogues biperiden and sila-biperiden are almost identical.
N2  - Die Antimuscarinica Sila-biperiden [rac-(SiRS,C2SR)-exo-2] und endo-Sila-biperiden [rac-(SiRS,C2SR)-endo-2] wurden ausgehend von Trichlor(vinyl)silan (Cl\(_3\)SiCH=CH\(_2\)) durch eine siebenstufige Synthese dargestellt. Die beiden Silanoie sind in inerten organischen Solvenzien konfigurationsstabil, unterliegen aber in wässeriger Lösung (pH 7.4, 3ZOC) einer Epimerisierung durch Inversion der Konfiguration am Silicium-Atom. Die relativen Konfigurationen von Sila-biperiden und endo-Sila-biperiden wurden durch Einkristall-Röntgenstrukturanalysen bestimmt. Beide Verbindungen bilden im Kristall intermolekulare 0-H · · · N-Wasserstoff- Brückenbindungen aus, die zum Aufbau von zentrosymmetrischen Dimeren (Sila-biperiden) bzw. unendlichen Ketten (endo-Sila-biperiden) führen. Sila-biperiden ist ein Silicium-Analogon (C/Si-Austausch) des Antiparkinsonmittels Biperiden [rac-(CRS,C2SR>-ao-1). Sowohl in funktionellen pharmakologischen Untersuchungen als auch in Radioligand-Kompetitionsexperimenten erwiesen sich Biperiden, Sila-biperiden und endo-Sila-biperiden als rein kompetitive Antagonisten an muscarinischen M1-, M2-, M3- und M4-Rezeptoren. Alle drei Verbindungen zeigten die höchste Affinität zu den Mt-Rezeptoren (pA\(_2\)-Werte: 8.72-8.80; pKrWerte: 8.8-9.1), eine deutlich geringere Affinität zu den M4- und M3-Rezeptoren und die niedrigste Affinität zu den kardialen M2-Rezeptoren (pA\(_2\)-Werte: 7.57-7.79; pKi-Werte: 7.7-7.8). Das Affinitätsprofil (Ml > M4 > M3 > M2) von Biperiden, Sila-biperiden und endo-Sila-biperiden ist dem des Mt-selektiven Antimuscarinicums Pirenzepin qualitativ sehr ähnlich. Die antimuscarinischen Eigenschaften der C/Si-Analoga Biperiden und Sila-biperiden sind nahezu identisch.
KW  - Anorganische Chemie
KW  - Silicon
KW  - Silanol
KW  - Sila-biperiden
KW  - Bioorganosilicon chemistry
KW  - Muscarinic antagonist
KW  - Muscarinic receptor subtype
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64303
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Wagner, S. A.
A1  - Brakmann, S.
A1  - Wuttke, F.
A1  - Eilert, U.
A1  - Fischer, L.
A1  - Syldatk, C.
T1  - Synthesis of acetyldimethyl(phenyl)silane and its enantioselective conversion into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane by plant cell suspension culytures of Symphytum officinale L. and Ruta graveolens L.
N2  - Starting from chlorodimethyl(phenyl)silane (3), acetyldimethyl(phenyl)silane (l) was prepared by a two-step synthesis in a total yield of 90% [PhMe\(_2\)SiCl (3)-> PhMe\(_2\)SiCCOMe)=CH\(_2\) (4)-> PhMe\(_2\)SiC(O)Me (1)]. The prochiral acetylsilane 1 was transfonned enantioselectively into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane [(R)-2] using plant cell Suspension cultures of Symphytum officinale L. or Ruta graveolens L. Under preparative conditions (300-mg scale, not optimized), (R)-2 was isolated in 15% (Symphytum) and 9% yield (Ruta), respectively. The enantiomeric purities of the products were 81% ee (Syrnphytum) and 60% ee (Ruta), respectively.
KW  - Anorganische Chemie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64299
ER  - 
TY  - JOUR
A1  - Eltze, M.
A1  - Ullrich, B.
A1  - Mutschler, E.
A1  - Moser, U.
A1  - Bungardt, E.
A1  - Friebe, T.
A1  - Gubitz, C.
A1  - Tacke, Reinhold
A1  - Lambrecht, G.
T1  - Characterization of muscarinic receptors mediating vasodilation in rat perfused kidney
N2  - The muscarinic receptor mediating vasodilation of resistance vessels in the rat isolated, constant-pressure perfused kidney (preconstriction by w- 7 M cirazoline) was characterized by subtype-preferring agonists and se]ective antagonists. The agonists produced vasodi1ation with the fol1owing rank order of potency: arecaidine propargy] ester (APE) > 5-methylfurtrethonium = methacholine = oxotremorine > (S)-aceclidine > arecaidine 2-butyne-1,4-diyl bisester > 4-Cl-McN-A-343 = (R)-nipecotic acid ethyl ester = N-ethyl-guvacine propargyl ester- (R)-aceclidine = (S)-nipecotic acid ethyl ester > McN-A-343. Agonist-induced vasodilation disappeared after destruction of the endothelium with detergent. Highly significant correlations of agonist potencies for vasodilation were found between rat kidney and guinea-pig ileum submucosal arterioles as weH as agonist potencies at smooth muscle muscarinic M\(_3\) receptors of the guinea-pig ileum. The rank order of antagonist potencies (4-diphenylacetoxy-Nmethylpiperidine methiodide (4-DAMP) > (R)-hexahydro-difenidol - hexahydro-sila-difenidol > pirenzepine - p-fluorohexahydro- sila-difenidol- himbacine- AF-DX 384- AQ-RA 741 > (S)-hexahydro-difenidol) to attenuate vasodilation to APE in rat kidney, correlated significantly with affinities at M\(_3\) receptors in submucosal arterioles and in smooth muscle of the guinea-pig ileum, but differed from those at M\(_1\) and M\(_2\) receptors in rabbit vas deferens. The agonist and antagonist potencies suggest that vasodilation elicited by muscarinic stimuli in endothelium-intact rat renal vasculature is mediated by functional muscarinic M\(_3\) receptors.
KW  - Anorganische Chemie
KW  - Kidney (perfused
KW  - rat)
KW  - Muscarinic receptor agonists
KW  - Muscarinic receptor antagonists
KW  - Arterioles (submucosal)
KW  - Ileum; Atrium
KW  - Vas deferens
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64283
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Becht, J.
A1  - Lopez-Mras, A.
A1  - Sheldrick, W. S.
A1  - Sebald, A.
T1  - Syntheses, X-ray crystal structure analyses, and solid-state NMR studies of some zwitterionic organofluorosilicates
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64272
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Lopez-Mras, A.
A1  - Becht, J.
A1  - Sheldrick, W. S.
T1  - Synthese sowie Kristall- und Molekülstruktur von Tetrafluoro[2-(pyrrolidinio)ethyl]silicat
T1  - Synthesis and Crystal and Molecular Structure of Tetrafluoro[2-(pyrrolidinio)etbyl]silicate
N2  - Das zwitterionische Tctratluoro[2-(pyrrolidinio) ethyl]silicat (4) wurde durch Reaktion von Trimethoxy( 2-pyrrolidinoethyl)silan (5) mit Fluorwasserstoff in einem Ethanol/Flußsäure-Gemisch bei 0 °C synthetisiert. Die Kristall- und Molekülstruktur von 4 wurde bei - 100 °C mittels einer Einkristall-Röntgenstrukturanalyse untersucht. Außerdem wurde 4 durch NMR-Untersuchungen in Lösung charakterisiert (CD\(_3\)CN: \(^1\)H, \(^{13}\)C).
N2  - The zwitterionic tetrafluoro[2-(pyrrolidinio) ethyl]silicate (4) was synthesized by reaction of trimethoxy( 2-pyrrolidinoethyl)silane (5) with hydrogen fluoride in elhanollhydrofluoric acid at 0 °C. The crystal and mo1ecular structure of 4 was studied at - 100 °C by singlc-crystal X-ray diffraction. ln addition, 4 was characterized by solution-state NMR sturlies (CD\(_3\)CN: \(^1\)H, \(^{13}\)C).
KW  - Anorganische Chemie
KW  - Zwitterionic
KW  - Lambda5-organofluorosilicate
KW  - pentacoordinate silicon
KW  - crystal structure
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64269
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Lopez-Mras, A.
A1  - Sperlich, J.
A1  - Strohmann, C.
A1  - Kuhs, W. F.
A1  - Mattern, G.
A1  - Sebald, A.
T1  - Neue zwitterionische \(\lambda_5\)-Spirosilicate: Synthesen, Einkristall-Röntgenstrukturanalysen und Festkörper-NMR-Untersuchungen
T1  - New Zwitterionic \(\lambda_5\)-Spirosilicates: Syntheses, Single-Crystal X-Ray Strudure Analyses, and Solid-State NMR Studies
N2  - The zwitterionic spirocyclic \(\lambda_5\) -Silicates bis(3,4,5,6-tetrabromo- 1,2-benzenediolato(2- ))[2-(pyrrolidinio)ethyl]silicate (5; and its monohydrate 5 · H\(_2\)O) and bis[1,2-benzenediolato(2- )][( dimethylammonio)methyl]silicate (6) were synthesized by various methods including Si-C bond cleavage reactions. The crystal structures of 5, 5 · H\(_2\)O, and 6 were investigated by Xray düfraction. Furthermore, 5, 5 · H\(_2\)O, 6, and the related zwitterionic \(\lambda_5\)-spirosilicates 1 · 1/4 CH\(_3\)CN, 2 · CH\(_3\)CN, 3 · CH\(_3\)CN, and 4 were characterized by solid-state NMR spectroscopy (\(^{29}\)Si and \(^{15}\)N CP/MAS). The pentacoordinate silicon atoms of 5, 5 · H\(_2\)O (two crystallographically independent ZWitterions and two crystallographically independent water molecules), and 6 (two crystallographically independent zwitterions) are surrounded by four oxygen atoms and one carbon atom. The coordination polyhedrons around the silicon atoms of 5 and 6 can be described as distorted (5) or nearly ideal (6) trigonal bipyramids, the carbon atoms being in equatorial positions. 5 forms intramolecular and 6 intermolecular (--+ formation of dimeric units) N- H···O hydrogen bonds. The coordination polyhedrons around the two crystallographically independent silicon atoms of 5 · H\(_2\)O can be described as a nearly ideal and slightly distorted square pyramid, respectively, the carbon atoms being in the apical positions. In the crystal lattice of 5 · H\(_2\)O, intermolecular N-H···O and 0-H···O hydrogen bonds between the zwitterions and water molecules are observed. The results obtained by X-ray diffraction and solid-state NMR spectroscopy are consistent for each compound studied.
KW  - Anorganische Chemie
KW  - Spirosilicates
KW  - zwitterionic
KW  - Silicon
KW  - pentacoordinate
KW  - Bond cleavage
KW  - Si-C I Solid-state NMR
KW  - 29Si and 15N
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64251
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Lopez-Mras, A.
A1  - Sheldrick, W. S.
A1  - Sebald, A.
T1  - Synthesen, Einkristall-Röntgenstrukturanalysen und \(^{29}\)Si-Festkörper-NMR-Untersuchungen eines zwitter- ionischen \(\lambda_5\)-Spirosilicats und eines käfigartigen Octa(silasesquioxans) : [Professor Hartmut Bärnighausen zum 60. Geburtstage gewidmet]
T1  - Syntheses, Single-Crystal x ... Ray Analyses and Solid-State \(^{29}\)Si NMR Studies of a Zwitterionic \(\lambda_5\)-Spirosilicate and a Cage-like Octa(silasesquioxane)
N2  - No abstract available
KW  - Anorganische Chemie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64243
ER  - 
TY  - JOUR
A1  - Waelbroeck, M.
A1  - Camus, J.
A1  - Tastenoy, M.
A1  - Mutschler, E.
A1  - Strohmann, C.
A1  - Tacke, Reinhold
A1  - Schjelderup, L.
A1  - Aasen, A.
A1  - Lambrecht, G.
A1  - Christophe, J.
T1  - Stereoselective interaction of procyclidine, hexahydro-difenidol, hexbutinol and oxyphencyclimine, and of related antagonists, with four muscarinic receptors
N2  - Wc invcstigatcd thc binding properlies of thc (R)- and (Sl-cnantiomcrs of thc muscarinic antagonists trihcxyphcnidyl, procyclidinc, hcxahydro-difcnidol. p-fluoro-hcxahydro-difcnidol. hcxbutinol, p-fluoro-hcxbutinnl. and thcir corrcsponding methiodidcs at muscarinic M\(_1\), M\(_2\)• M\(_3\) and M\(_4\) receptor subtypes. In addition. binding properlies of thc (R)- and (S)-cnantiomcrs of oxyphcncycliminc wcrc studicd. The {R)- cnantiomcrs (cutomcrs} of all the compounds had a grcatcr affinity than the (S)-isomcrs for thc four muscarinic rcccptor subtypcs. Thc binding pattcrns of thc (R)- and (S)-enantiomers wcrc gcncrally different. We did not obscrvc any gcncral corrclation hctwccn thc potcncy of thc high-affinity enantiomer and Lhc affinity ratio (cudismic ratio) of the two cnantiomcrs. Thc rcsuhs arc discusscd in tcrms of a 'four suhsitcs' binding modcl.
KW  - Anorganische Chemie
KW  - Muscarinic receptors
KW  - Hexahydro-difenidol
KW  - Oxyphencyclimine
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64237
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Becker, B.
A1  - Berg, D.
A1  - Brandes, W.
A1  - Dutzmann, S.
A1  - Schaller, S.
T1  - Bis(4-fluorophenyl)methyl(1H-1,2,4-triazol-1-yl-methyl)germane, a germanium analogue of the agricultural fungicide flusilazole: synthesis and biological properties
N2  - Bis( 4-fluorophenyl)methyl(l H-1,2,4-triazol-1-yl-methyl)germane (2), a germanium analogue of the agricultural fungicide flusilazole (1), has been synthesized from Cl\(_3\)GeCH\(_2\)CI (3) by both a three-step and a four-step synthesis (3-> (p-F-C\(_6\)H\(_4\))\(_2\)Ge(CH\(_2\)Cl)Br (4)-> (p-F-C\(_6\)H\(_4\))\(_2\)Ge(CH\(_2\)CI)CH\(_3\) (S)-> 2; S ~ (p-F-C\(_6\)H\(_4\))\(_2\)Ge(CH\(_2\)I)CH\(_3\) (6)-> l). The fungicidal properties of l have been compared with those of the parent silicon compound 1 (studies on Si/Ge bioisosterism). In various test systems, the SijGe analogues 1 and 2 showed comparable fungicidal properlies (in activity against plant pathogenic fungi: in agar plate diffusion tests and greenhause evaluations; in activity against human pathogenic fungi: in serial dilution tests). In addition, 1 and 2 displayed comparable potencies in respect of sterol biosynthesis inhibition in Sacclulromycopsis üpolytica and Pyricularia oryzae, the mode of action being primarily an inhtbition of oxidative C14-demethylation.
KW  - Anorganische Chemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64224
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Becht, J.
A1  - Mattern, G.
A1  - Kuhs, W. F.
T1  - Zur Existenz zwitterionischer \(\lambda_5\)-(Ammonioorganyl)tetrafluorosilicate: Synthese sowie Kristall- und Molekülstruktur von Tetrafluoro(pyrrolidiniomethyl)silicat
T1  - On the Existence of Zwitterionic \(\lambda_5\)-(Ammonioorganyl)tetrafluorosillcates: Synthesis and Crystal and Molecular Structure of Tetrafluoro(pyrrolidiniomethyl)silicate
N2  - The zwitterionic tetrafluoro(pyrrolidiniomethyl)silicate (6) was synthesized by the reaction of trimethoxy(pyrrolidinomethyl) silane (7) with hydrogen fluoride in ethanol/hydrofluoric acid (yield 83%). 6 crystallizes in the space group P2\(_1\)fc with two crystallographically distinct molecules in the asymmetric unit. In both molecules the pentacoordinate silicon atom is surrounded by four fluorine atoms and one carbon atom, the latter being in an equatorial position. The coordination polyhedron of the silicon atoms can be described as a slightly distorted trigonal bipyramid. The zwitterionic structure was also proved for dissolved 6 (solution in CD\(_3\)CN, NMRspectroscopic studies).
KW  - Anorganische Chemie
KW  - Fluorosilicates
KW  - zwitterionic
KW  - Pentacoordinate silicon
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64217
ER  - 
TY  - JOUR
A1  - Bungardt, E.
A1  - Vockert, E.
A1  - Feifel, R.
A1  - Moser, U.
A1  - Tacke, Reinhold
A1  - Mutschler, E.
A1  - Lambrecht, G.
A1  - Suprenant, A.
T1  - Characterization of muscarinic receptors mediating vasodilation in guinea-pig ileum submucosal arterioles by the use of computer-assisted videomicroscopy
N2  - Muscarinic receptors of rcsistance vessels (submucosal artcrioles, outside diametcr 50-75 J,Lm) from the guinea-pig small intestinc were invcstigatcd in vitro using a computcr-assisted vidcomicroscopy system (Diamtrak <~t ). The muscarinic receptor which mediates vasodilation of prccontractcd [U-46619 (300 nM) or (- )-noradrcnaline (1 0 J.L M)] artcriolcs was characterized with scveral muscarinic agonists and subtypc-sclectivc antagonists. Thc following agonists all produccd cquivalent maximum vasodilation (given in rank ordcr of potency): acctylcholinc = arccaidinc propargyl cstcr (APE) > oxotremorine = ( ± )-muscarinc = ( ± )-mcthacholinc > carbachol > 4-[[N-{4-chlorophenyl)carbamoyl]oxy]-2-hutynyltrimcthylammonium iodide (4-CI-McN-A- 343). 4-([N-(3-ChlorophcnyD-carbamoyl)oxy]-2-butynyltrimcthylammonium chloride (McN-A-343) and N-ethyl-guvacinc propargyl ester (NEN-APE) produccd minimal or no artcriolar vasodilation. Thc muscarinic antagonists pircnzcpinc, ( ± )-5,11-dihydro-11- [[[2-[2-((dipropylamino)methyl}-1-pipcridinyl]ethyl]amino ]-carbonyi]-6H-pyrido(2,3-h)( 1 ,4)-benzodiazcpin-6-onc (AF-DX 384 ), 11- [[ 4-[4-(dicthylamino)butyl]-1-piperidinyl]acetyl]-5, ll-dihydro-6H-pyrido(2.3-h)( 1,4 )-bcnzodiazepin-6-onc (AQ-RA 741 ), p-fluorohexahydro- sila-difcnidol (p-F-HHSiD), 4-diphcnylacetoxy-N-methylpipcridine mcthiodidc (4-DAMP) and (R)- and (S)hexahydro- difcnidol [(R)-HHD, (S)-HHD] shifted thc muscarinc, mcthacholinc or carbachol dosc-rcsponsc curve to the right in a compctitive manner. Schildanalysis of the data yicldcd pA\(_2\) valucs for pircnzcpinc (6.74/6.9), AF-DX 384 (6.72), AQ-RA 741 (6.58), p-F-HHSiD (7.53/7.57), 4-DAMP (9.06), (R)-HHD (7.88/8.32) and (S)-HHD (5.52/5.88). Thus, it can he concluded that submucosal arteriolcs posscss only the M\(_3\) functional muscarinic reccptor, the activation of which causcs hlood vcsscl dilation. The preparation dcscribcd is considcrcd to be a valuable now bioassay for pharmacological investigations of drug actions at muscarinic receptors in the peripheral vascular system.
KW  - Anorganische Chemie
KW  - Muscarinic receptor subtypes; Muscarinic rcceptor agonists (M 1-selective)
KW  - Muscarinic receptor antagonists (M 3-selective)
KW  - Vidcomicroscopy
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64206
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Wiesenberger, F.
A1  - Becker, B.
A1  - Rohr-Aehle, R.
A1  - Schneider, P. B.
A1  - Ulbrich, U.
A1  - Sarge, S. M.
A1  - Cammenga, H. K.
A1  - Koslowski, T.
A1  - Niessen, W. von
T1  - Ester von (Hydroxymethyl)diorganylsilanen: Synthese und thermisch induzierte Umlagerung
T1  - Esters of (Hydroxymethyl)diorganylsllanes: Synthesis and Thermally Induced Rearrangement
N2  - Twenty silanes of the type R\(^1\)R\(^2\)Si(H)CH\(_2\)OR\(^3\) (A) were syn- and entropy of activation) of these reactions were studied by thesized {R\(^1\), R\(^2\) = Me, Ph, 1-naphthyl, PhCH\(_2\), Me\(_3\)SiCH\(_2\); OR\(^3\) means of düferential scanning calorimetry (DSC). In addition, = OC(O)Me, OC(O)Ph, OC(O)CF\(_3\) , OS(0)\(_2\)CF\(_3\), OP(O)Ph\(_2\), the kinetics of all reactions were investigated by 1H-NMR OC(O)Cl, and studied for their thermal behaviour. The silanes spectroscopy. The transition state of the rearrangement was A undergo a thermally induced rearrangement to give the investigated by an ab initio study based on the model comcorresponding silanes R\(^1\)R\(^2\)Si(OR\(^3\))Me (B). For compounds with pound H\(_3\)SiCH\(_2\)OC(O)H (-> MeH\(_2\)SiOC(O)H]. The theoretical OR3 = OC(O)Cl, an additional decarboxylation takes place to data and the experimentally obtained energetic and kinetic yield the chlorosilanes R1R2Si(Cl)Me. Except for the deriva- data are discussed in terms of mechanistic aspects of the retives with OR\(^3\) = OC(O)Cl, the energetic (reaction enthalpy) arrangement reaction A -> B. and kinetic data (reaction order, frequency factor, enthalpy ...
KW  - Anorganische Chemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64188
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Hengelsberg, H.
A1  - Klingner, E.
A1  - Henke, H.
T1  - Synthese der Si-funktionellen Acetylsilane tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiF und tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiH sowie Synthese und Kristallstruktur des Acetylsilanols tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiOH: Substrate für mikrobielle Reduktionen
N2  - The racemic Si-functional acetylsilanes tBu(Me\(_3\)SiCH\(_2\))[ MeC(O)]SiF (1) and tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiH (2) and the racemic acetylsilanol tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiOH (3) were synthesized from Si(OMe)\(_4\) (4) as substrates for microbial reductions [4 -> tBuSi(OMe)\(_3\) (5) -> tBu(Me\(_3\)SiCH\(_2\))Si(OMe)\(_2\) (6) -> tBu(Me\(_3\)SiCH\(_2\))SiF\(_2\) (7)-> tBu(Me\(_3\)SiCH\(_2\))(CH\(_2\) = C(OMe))SiF (8) -> 1; 8 -> tBu(Me\(_3\)SiCH\(_2\))[CH\(_2\) = C(OMe)]SiH (9) -> 2; 6 -> tBu(Me\(_3\)SiCH\(_2\))[CH\(_2\) = C(OMe)]SiOMe (10) -> 3]. Compounds 1-3 were found to be reduced by cells of Trigonapsis variabilis (DSM 70714) ( = SiC(O)Me -> = SiCH(OH)Me}. The crystal and molecular structure of 3 was studied by singlecrystal X-ray diffraction. In the crystal, racemic 3 forms infinite chains built up by intermolecular 0-H .. ·O bonds between the hydroxyl and acetyl groups of molecules of the same absolute configuration.
KW  - Anorganische Chemie
KW  - Silanes
KW  - acetyl-
KW  - Si-functional
KW  - Silanol
KW  - crystal structure of
KW  - Microbial reduction
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64192
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Mahner, K.
A1  - Strohmann, C.
A1  - Forth, B.
A1  - Mutschler, E.
A1  - Friebe, T.
A1  - Lambrecht, G.
T1  - Cyclohexyl(4-fluorophenyl)(3-piperidinopropyl)silanol (p-fluoro-hexahydro-sila-difenidol, p-F-HHSiD) and derivatives: synthesis and antimuscarinic properties
N2  - Four different syntheses of the potent and selective muscanruc antagonist cyclohexyl( 4- fluorophenyl)(3-piperidinopropyl)silanol ( p-fluoro-hexahydro-sila-difenidol, p-F-HHSiD (2b); isolated as hydrochloride 2b· HCl) are described (starting materials: (CH\(_3\)O)\(_2\)SiCH\(_2\)CH\(_2\)CH\(_2\)Cl and Si(OCH\(_3\))\(_4\) ). In addition, the synthesis of the corresponding carbon analogue p-fluoro-hexahydro-difenidol ( p-F-HHD (2a); isolated as 2a· HCI) and the syntheses of three p-F-HHSiD derivatives (3-5), with a modified cyclic amino group, are reported (3: piperidinojpyrrolidino exchange, isolated as 3· HCI; 4: piperidinoj hexamethylenimino exchange, isolated as 4 · HCl; 5: quaternization of 2b with methyl iodide). The chiral compounds 2a, 2b, 3, 4 and 5 were prepared as racemates. In functional pharmacological studies, 3-5 behaved as simple competitive antagonists at musearlnie Ml receptors in rabbit vas deferens, M2 receptors in guinea-pig atria, and M3 receptors in guinea-pig ileal smooth rnuscle. The pyrrolidino (3) and hexamethylenimino (4) analogues of the parent drug p-F-HHSiD (2b) displayed the highest affinity for Ml and M3 receptors (pA\(_2\) values: 7.0-7.4) but exhibited lower affinity for cardiac M2 receptors (pA\(_2\) : 5.9 and 6.0). Their affinity profile (Ml- M3 > M2) is different from that of p-F-HHSiD (2b) (M3 > Ml > M2), but qualitatively very similar tothat of p-F-HHD (2a). The methiodide 5 exhibited the highest affinity for Ml receptors (pA\(_2\) : 8.5) but lower affinity for M2 and M3 receptors by factors of 5.6 and 3.6, respectively.
KW  - Anorganische Chemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64162
ER  - 
TY  - JOUR
A1  - Hengelsberg, H.
A1  - Tacke, Reinhold
A1  - Fritsche, K.
A1  - Syldatk, C.
A1  - Wagner, F.
T1  - Synthesis and enantioselective enzymatic hydrolysis of rac-dimethylphenyl[1-(phenylacetamido)- ethyl]silane
N2  - Racemic dimethylphenyl(l-(phenylacetamido)ethyl)silane [rac-5) has been made by a four-step synthesis starting from (chloromethyl)dimethylphenylsilane [PhMe\(_2\)SiCH2Cl (1) ~ PhMe\(_2\)SiCH(Cl)Me (rac-2) - PhMe\(_2\)SiCH(l)Me (rac-3) - PhMe2SiCH(NH2)Me (rac-4) ~ PhMe\(_2\)SiCH[N(H)C(O)CH\(_2\)Ph]Me ( rac-5); total yield 41% ). Enantioselective enzymatic hydrolysis of rac-5, catalyzed by immobilized penicillin G acylase (E.C. 3.5.1.11) from Escherichia coli 5K (pHM 12), gave (R)-(1- aminoethyl)dimethylphenylsilane [( R )-4] in 40% yield with an enantiomeric purity of 92% ee.
KW  - Anorganische Chemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64153
ER  - 
TY  - JOUR
A1  - Strohmann, C.
A1  - Bauerecker, S.
A1  - Cammenga, H. K.
A1  - Jones, P. G.
A1  - Mutschler, E.
A1  - Lambrecht, G.
A1  - Tacke, Reinhold
T1  - Enantiomers of the muscarinic antagonist 1-cyclohexyl-1-(4-fluorophenyl)-4-piperidino-1-butanol (p-fluoro-hexahydro-difenidol): synthesis, absolute configuration, and enantiomeric purity
N2  - The enantiomers of the antimuscarinic agent 1-cyclohexyl-1- (4-fluorophenyl)-4-piperidino-1-butanol [(R)- and (S)-p-fluorohexahydro- difenidol] ((R)- and (S)-2a] and their methiodides (R)- 3 and (S)-3 were prepared with high enantiomeric purity. (R)- 2a and (S)-2a (isolated as hydrochlorides) were obtained by catalytic hydrogenation (Pd/C contact) of the corresponding enantiomers of 1-cyclohexyl-1-( 4-fl uorophen yl)-4-piperidino- 2-butyn-1-ol [(R)- and (S)-4]. Reaction of (R)-2a and (S)-2a with rnethyl iodide led to (R)-3 and (S)-3, respectively. The unsaturated precursors (R)- and (S}-4 (enantiorneric purity ~ 99.80 and ~99.94% e.e.; calorimetric analysis) were prepared by res-sepaolution of rac-4 [available from 4-FC\(_6\)H\(_4\)C(O)C\(_6\)H\(_{11}\) by reaction with LiC ~ CCH\(_2\)NC\(_5\)H\(_{10}\)] using (R)- and (S)-mandelic acid as resolving agents. The absolute configurations of the (R) and (S) enantiomers of 2a, 3, and 4 were determined by an X-ray crystal-structure analysis of (S)-5, the methiodide of (S)-4. (R)- 2a and (R)-3 exhibit a higher affinity for muscarinic M1, M2, M3, and M4 receptors (by up to two orders of magnitude) than their corresponding antipodes (S)-2a and (S)-3, the degree of stereoselectivity depending on the receptor subtype involved. (R)-2a represents a useful tool for rnuscarinic receptor research (affinity profile: M1 ~ M3 ~ M4 > M2).
KW  - Anorganische Chemie
KW  - Difenidol
KW  - p-fluoro-hexahydro-
KW  - enantiomers of / Muscarinic receptors
KW  - subtypes of
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64144
ER  - 
TY  - JOUR
A1  - Waelbroeck, M.
A1  - Camus, J.
A1  - Tastenoy, M.
A1  - Mutschler, E.
A1  - Strohmann, C.
A1  - Tacke, Reinhold
A1  - Lambrecht, G.
A1  - Christophe, J.
T1  - Stereoselectivity of (R)- and (S)-hexahydro-difenidol binding to neuroblastoma M\(_1\), cardiac M\(_2\), pancreatic M\(_3\), and striatum M\(_4\) muscarinic receptors
N2  - (R)-Hexahydro-difenidol has a higher affinity for M\(_1\) receptors in NB-OK 1 cells, pancreas M\(_3\) and striatum M\(_4\) receptors (pKi 7.9 to 8.3) than for cardiac M2 receptors (pKi 7 .0). (8)-Hexahydro-difenidol, by contrast, is nonselective (pKi 5.8 to 6.1). Our goal in the present study was to evaluate the importance ofthe hydrophobic phenyl, and cyclohexyl rings of hexahydro-difenidol for the stereoselectivity and reeeptor selectivity of hexahydro-difenidol binding to the four muscarinic receptors. Our results indieated that replacement of the phenyl ring of hexahydro-difenidol by a cyclohexyl group <~ dicyclidol) and ofthe cyclohexyl ring by a phenyl moiety <~ difenidol) indueed a !arge (4- to 80-fold) decrease in binding affinity for all musearlnie receptors. Difenidol had a signifieant preference for M\(_1\) , M\(_3\) , and M\(_4\) over M\(_2\) receptors; dicyclidol, by eontrast, had a greater affinity for M\(_1\) and M\(_4\) than for M\(_2\) and M\(_3\) receptors. The binding free energy deerease due to replacement ofthe phenyl and the cyelohexyl groups of(R)-hexahydro-difenidol by, respectively, a eyclohexyl and a phenyl moiety was almostadditive in the ease of M\(_4\) (striatum) binding sites. In the ease ofthe cardiac M\(_2\), pancreatic M\(_3\) , or NB-OK 1 M\(_1\) receptors the respective binding free energies were not eompletely additive. These results suggest that the four (R)-hexahydro-difenidol ''binding moieties" (phenyl, cyclohexyl, hydroxy, and protonated amino group) cannot simultaneously form optimal interaetions with the M\(_1\), M\(_2\), and M\(_3\) muscarinic receptors. When eaeh of the hydrophobic groups is modified, the position of the whole molecule, relative to the four subsites, was changed to allow an optimal overall interaction with the musearlnie receptor.
KW  - Anorganische Chemie
KW  - hexahydro-difenidol enantiomers
KW  - muscarinic receptor subtypes
KW  - stereoselective interaction
KW  - difenidol
KW  - dicyclidol
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64135
ER  - 
TY  - JOUR
A1  - Waelbroeck, M.
A1  - Camus, J.
A1  - Tastenoy, M.
A1  - Mutschler, E.
A1  - Strohmann, C.
A1  - Tacke, Reinhold
A1  - Lambrecht, G.
A1  - Christophe, J.
T1  - Binding affinities of hexahydro-difenidol and hexahydro-sila-difenidol analogues at four muscarinic receptor subtypes: constitutional and stereochemical aspects
N2  - Hexahydro-sila-difenidoJ and eight analogues behaved as simple cumpetitive inhibitors of eHJN·methyl·scopoJamine binding to homogenates frorn human neuroblastoma NB-OK 1 cells (M\(_1\) sites), rat heart (M\(_2\) sites), rat pancreas (M\(_3\) sites), and rat striatum 'B' sites (M\(_4\) sites). Pyrrolidino- and hexamethyleneimino analogues showed the same sekctivity profile as the parent compound. Hexahydro-sila-difenidol methiodide and the methiodide of p-fluoro-hexahydro·sila-difenidol had a fügher affinity but a lower selectivity than the tertiary amines. Compounds containing a p·methoxy, p-chJoro or p-fluoro substituent in the phenyl ring of hexahydro-sila-difenidol showed a qualitative)y similar selectivity profile as the parent compound (i.e., M\(_1\)= M\(_3\) = M\(_4\) >M\(_2\) ), but up to 16-fold lower affinities. o-Methoxy-hexahydro-sila-difenidol has a lower affinity than hexahydro-sila-difeni.:!o! at the four binding sites. lts selectivity profile (M\(_4\) > M\(_1\), M\(_3\) > M\(_2\) ) was different from hexahydro-sila-difenidol. Replacement of the centrat silicon atom of hexahydro-sila-difenidol, p-fluoro-hexahydro-sila-difenidol and thdr quatemary (N-methylated) analogues by a carbon atom did not change their binding affinities significantly. The iour muscarinic receptors showed a higher affinity for the (R)- than for the (S)-enantiomers of hexahydro-difenidol, p-fluorohexahydro-difenidol and their methiodides. The stereoselectivity varied depending on the receptor subtype and drug considered.
KW  - Anorganische Chemie
KW  - Muscarinic receptor antagonists (selective)
KW  - Hexahydro-sila-difenidol analogues
KW  - p-Fluoro-hexahydro-sila-difenidol
KW  - Stereoselectivity
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64128
ER  - 
TY  - JOUR
A1  - Dörje, F.
A1  - Wess, J.
A1  - Lambrecht, G.
A1  - Tacke, Reinhold
A1  - Mutschler, E.
A1  - Brann, M. R.
T1  - Antagonist binding profiles of five cloned human muscarinic receptor subtypes
N2  - A variety of muscarinic antagonists are currently used as tools to pharmacologically subclassify muscarinic receptors into M\(_1\), M\(_2\) and M\(_3\) subtypes. ln the present study I we have determined the affinity proflies of several of these antagonists at five cloned human muscarinic receptors (m1-m5) stably expressed in Chinesehamster ovary cells (CHO-K1). At all five receptorsl the (R)-enantiomers of trihexyphenidyl and hexbutinol displayed considerably higher affinities (up to 525-fold) than their corresponding (S)-isomers. The stereoselectivity ratios [inhibition constant( S)/inhibition constant(R)] for both pairs of enantiomers were lowest at m2 receptors, suggesting that less stringent configurational demands are made by this receptor subtype. The "M\(_1\)-selective" antagonist (R)-trihexyphenidyl displayed high affinities for m1 and m4 receptors. The "M\(_2\)-selective" antagonists himbacinel (±}-5, 11-dihydro-11-1[(2-[(dipropylamino)methyl]-1- piperidinyllethyl)amino]carbonyii-6H-pyrido(213-b)(1 ~4)benzodiazepine- 6-one (AF-DX 384)1 11-(14-[4-(diethylamino)butyl)-1-piperidinyll acetyl)-5~ 11-dihydro-6H-pyrido(2~3-b) (1~4)benzodiazepine-6-one (AQ-RA 741) and (+K11-(12-[(diethylamino)methyl]-1-piperidinyll acetyl)-5~ 11-di-hydro-6H-pyrido(2~3-b)(1,4)benzodiazepine-6-one (AF-OX 250; the (+)-enantiomer of AF-DX 116] exhibited high affinities for m2 and m41 intermediate affinities for m1 and m3 and low affinities for m5 receptors. This selectivity profile was most prominent for AQ-RA 7 41 I which displayed 195- and 129-fold higher affinities for m2 and m4 receptors than for mS receptors. The "M\(_3\)-selective" antagonist (±)-p-fluoro-hexahydro-sila-difenidol hydrochloride (pFHHsiD) exhibited high affinity for m1 I m3 and m4 receptors. 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) bound with up to 7 -fold higher affinities to m1 I m31 m4 and m5 receptors than to m2 receptors. Although none of the tested antagonists showed more than 2-fold selectivity for one subtype over all other subtypes, each receptor displayed a unique antagonist binding profile.
KW  - Anorganische Chemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64113
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Brakmann, S.
A1  - Wuttke, F.
A1  - Fooladi, J.
A1  - Syldatk, C.
A1  - Schomburg, D.
T1  - Stereoselective microbial reduction of racemic acetyl(t-butyl)methylphenylsilane by Trigonopsis variabilis (DSM 70714) and Corynebacterium dioxydans (ATCC 21766)
N2  - (SiR,CR)- and (SiS,CR)-t-butyl(l-hydroxyethyl)methylphenylsilane [(SiR,CR)-2 and (SiS,CR)-3] have been prepared by (R)-selective microbial rcduction of racemic acetyl(t-butyl)methylphenylsilane (rac-1) using resting free cells of the yeast Trigonopsis variabilis (DSM 70714) or the bacterium Corynebacterium dioxydans (ATCC 21766). The biotransfonnations were carried out on a 10 g scale. Afterseparation by column chromatography on silica gel, the optically active diastereomers (SiR,CR)-2 and (SiS,CR)-3 produccd by T. variabilis were obtained in good yields [74% ((SiR,CR)-2). 78% ((SiS,CR)-3)]. The products obtained from the reduction with C. dioxydans were isolated in significantly lower yields [20% ((SiR,CR)-2), 20% ((SiS,CR)-3)]; reaction conditions not optimized). Both bioconversions gave products with high enantiomeric purities (T. variabilis: 91% ee ((SiR,CR)-2), 96% ee ((SiS,CR)-3); C. dioxydons: ~ 991 ee ((SiR,CR)-l), ~ 99% ee ((SiS,CR)-3)). To throw light on the stereochemical aspects of these biotransfonnations, an X-ray diffraction study was carried out on the 3,5-dinitrobenzoate of rac-(SiR,CS/SiS,CR)-3. In addition, 1H NMR spectroscopic stereochemical correlation studies were performed with the (S)-MTPA esters derived from (SiR,CR)-l, (SiS,CR)-3, rac-(SiR,CRjSiS,CS)-2 and rac-(SiR,CSjSiS,CR)-3 [rac-(SiR,CR/ SiS,CS)-2 and rac-(SiR,CS/SiS,CR)-3 were obtained by reduction of rac-1 with LiAIH\(_4\) in diethylether, followed by chromatographic separation of the diastereomers on silica gel]. These stereochemical studies allowed assignment of the absolute configurations and enantiomeric purities of the biotransformation products.
KW  - Anorganische Chemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64109
ER  - 
TY  - JOUR
A1  - Strohmann, C.
A1  - Tacke, Reinhold
A1  - Mattern, G.
A1  - Kuhs, W. F.
T1  - Bis(2,3-naphthalindiolato)[2-(pyrrolidinio)ethyl]silicat: Synthese und strukturelle Charakterisierung eines zwitterionischen \(\lambda_5\)-Spirosilicates
N2  - The zwi tterionic spirocyclic bis(2,3-naphthalenediolato )[2-(pyrrolidinio )ethyl]silicate [ ( C\(_{10}\)H\(_6\)O\(_2\)-SiCH\(_2\)CH\(_2\)(H)NC\(_4\)H\(_8\), 3 was synthesized and its structure characterized (single crystal X-ray structural analysis; \(^1\)H, \(^{13}\)C and \(^{29}\)Si NMR studies of solutions in DMSO). 3 was obtained by reaction of cyclohexylmethoxyphenyl(2-pyrrolidinoethyl)silane [C\(_6\)H\(_{11}\)(CH\(_3\)O)Si(C\(_6\)H\(_5\))CH\(_2\)CH\(_2\) NC\(_4\)H\(_8\), 4] with 2,3-dihydroxynaphthalene [C\(_{10}\)H\(_6\)(OH)\(_2\)] in acetonitrile at room temperature (isolated as 3·CH\(_3\)CN, yield 81 %). The formation of 3 involves two unusual Si-C cleavage reactions (cleavage of Si-C\(_6\)H\(_5\) and Si-C\(_6\)H\(_{11}\) under mild reaction conditions). In addition, 3 was prepared by reaction of 2,3-dihydroxynaphthalene with dimethoxyphenyl(2-pyrrolidinoethyl)silane [C\(_6\)H\(_5\) (CH\(_3\)O)\(_2\)SiCH\(_2\)CH\(_2\)NC\(_4\)H\(_8\) , 5] and trimethoxy( 2-pyrrolidinoethyl)silane [(CH\(_3\)O)\(_3\)SiCH\(_2\)CH\(_2\)NC\(_4\)H\(_8\), 6], respectively (isolated as 3·CH\(_3\)CN; yields 83 and 86%, respectively). 3·CH\(_3\)CN crystallizes in the space group Pbca with a = 8.877(2) A. b-= 22.823(4) Ä, c""" 24.597(4) A, and Z = 8 (R- 0.0592, Rw = 0.0529). The pentacoordinated Si atom of 3·CH\(_3\)CN is surrounded by its ligands in a nearly ideal square-pyramidal fashion (four basal 0 atoms and one apical C atom). The CH3CN molecule does not coordinate to the Si atom.
N2  - Das Zwitterionische spirocyclische Bis(2,3-naphthalindiolato )[2-(pyrrolidinio )ethyl)silicat [( C\(_{10}\)H\(_6\)O\(_2\)-SiCH\(_2\)CH\(_2\)(H)NC\(_4\)H\(_8\), 3) wurde synthetisiert und strukturell charakterisiert (Einkristallröntgenstrukturanalyse von 3·CH\(_3\)CN; \(^1\)H-, \(^{13}\)C- und \(^{29}\)Si-NMR-Untersuchungen von Lösungen in DMSO). 3 wurde durch Reaktion von Cyclohexylmethoxyphenyl(2·pyrrolidinoetbyl)silan [C\(_6\)H\(_{11}\)(CH\(_3\)O)Si(C\(_6\)H\(_5\))CH\(_2\)CH\(_2\) NC\(_4\)H\(_8\), 4] mit 2,3-Dihydroxynaphthalin [C\(_{10}\)H\(_6\)(OH)\(_2\)] in Acetonitril bei Raumtemperatur erhalten (isoliert als 3·CH\(_3\)CN, Ausbeute 81%). Der Bildung von 3 liegen zwei ungewöhnliche Si-eSpaltungen zugrunde (Spaltung von Si-C\(_6\)H\(_5\) und Si-C\(_6\)H\(_{11}\) unter milden Reaktionsbedingungen). 3 wurde auch durch Reaktion von 2,3-Dibydroxynaphthalin mit Dimethoxyphenyl(2-pyrrolidinoethyl)silan [C\(_6\)H\(_5\) (CH\(_3\)O)\(_2\)SiCH\(_2\)CH\(_2\)NC\(_4\)H\(_8\), 5) bzw. Trimethoxy(2-pyrrolidinoethyl)silan [(CH\(_3\)O)\(_3\)SiCH\(_2\)CH\(_2\)NC\(_4\)H\(_8\),6] dargestellt (isoliert als 3·CH\(_3\)CN, Ausbeute 83 bzw. 86%). 3·CH\(_3\)CN kristallisiert in der Raumgruppe Pbca mit a- 8.877(2) b = 22.823(4), c- 24.597(4) A und Z-8 (R == 0.0592,
KW  - Anorganische Chemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64095
ER  - 
TY  - JOUR
A1  - Feifel, R.
A1  - Rodrigues de Miranda, J. F.
A1  - Strohmann, C.
A1  - Tacke, Reinhold
A1  - Aasen, A. J.
A1  - Mutschler, E.
A1  - Lambrecht, G.
T1  - Selective labelling of muscarinic M\(_1\) receptors in calf superior cervical ganglia by [\(^3\)H](\(\pm\))-telenzepine
N2  - A method was developed to detennine the affinities of antimuscarinic drugs at M\(_1\) receptors. [\(^3\)H](±)-Telenzepine served as radioligand in crude preparations of calf superior cervical ganglia and showed high affinity for a single receptor population. consisting of M1 receptors (K\(_D\) = 1.12 nM). Kinetic experiments showed monophasic association (k\(_1\) =0.017 min\(^{-1}\) nM\(^{-1}\) ) and dissociation (k\(_1\) = 0.017 min\(^{-1}\) ) kinetics, the half-life of dissociation being 41 min at 37°C. The kinetie K\(_D\) value amounted to 1.00 nM. M\(_1\) affinities for pirenzepine, methoctramine. hexahydro-sila-difenidol and p-fluoro-hexahydro-sila-difenidol detennined in competition experiments were similar to those found in functional studies with MI receptors in rabbit isolated vas deferens. The binding assay was used to deterriline the affinities of the (R) and (S) enantiomers of tertiary (trihexyphenidyl, hexahydro-difenidol. hexbutinol, p-fluoro-hexbutinol) and quatemary musearlnie antagonists (trihexyphenidyl methiodide. hexbutinol methiodide). Comparison of results obtained with the rabbit vas deferens suggested that the ionic environment may influence the affinities.
KW  - Anorganische Chemie
KW  - Muscarinic M1 receptors
KW  - Superior cervical ganglia (calf)
KW  - Hexahydro-difenidol analogues
KW  - Trihexyphenidyl
KW  - Hexbutinol
KW  - Stereoselectivity
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64082
ER  - 
TY  - JOUR
A1  - Dörje, F.
A1  - Friebe, T.
A1  - Tacke, Reinhold
A1  - Mutschler, E.
A1  - Lambrecht, G.
T1  - Novel pharmacological profile of muscarinic receptors mediating contraction of the guinea-pig uterus
N2  - The present study was designed to further characterize the muscarinic receptors mediating contraction of the guinea-pig uterus. The affinities of various selective muscarinic antagonists were determined and compared with those obtained at M\(_1\) (rabbit vas deferens), M\(_2\) (guinea-pig atria) and M\(_3\) receptors (guinea-pig ileum). The contractile responses of uterine smooth muscle from immature guinea-pigs to carbachol (pD\(_2\) = 5.73) were competitively antagonized by pirenzepine (pA\(_2\) = 7.04), AF-DX 116 (11-[[2-[(diethylamino)methyl]-1-piperidinyl] acetyl]- 5,11-dihydro-6H -pyrido[2,3-b][1 ,4]benzo. diazepin-6-one) (pA\(_2\) = 6.96), himbacine (pA\(_2\) = 7.92), methoctramine (pA\(_2\) = 7.52), 4-DAMP (4-diphenylacetoxy- N-methylpiperidine methiodide) (pA\(_2\) = 8.87) and sila-hexocyclium (pA\(_2\) = 8.81). A comparison of affinity values indicates that the muscarinic receptors present in guinea-pig uterus display a novel pharmacological profile which is not consistent with the presence of either an M\(_1\), M\(_2\) or M\(_3\) receptor. The affinities determined for the different antagonists rather showed a close similarity to those obtained at muscarinic receptors present in rat striatum and NG108-15 cells which are considered pharmacological equivalents (M\(_4\) receptors) of the m4 gene product. We thus hypothesize that the guinea-pig isolated uterus preparation may serve as a simple functional assay system to study the pharmacology of M\(_4\) receptors.
KW  - Anorganische Chemie
KW  - Muscarinic receptors
KW  - M4 receptors
KW  - Guinea-pig uterus
KW  - Pirenzepine
KW  - Methoctramine
KW  - Sila-hexocyclium
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64071
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Becker, B.
A1  - Lange, H.
T1  - (Thioacetoxy-S-methyl)diorganylsilane und (Mercaptomethyl)diorganylsilane: Synthese und Eigenschaften
N2  - Die erstmalige Synthese der (Thioacetoxy-S-methyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (9) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (10) und der (Mercaptomethyl) diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SH (11) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SH (12) wird beschrieben. Während sich die Silane 9 und 10 leicht handhaben lassen, neigen die strukturanalogen (Hydroxymethyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)OH (1) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OH (2) zu einer basenkatalysierten Zersetzung (Bildung oligomerer (polymerer) Alkoxysilane und Wasserstoff). Im Gegensatz zu den thermisch labilen (Acetoxymethyl)diorganylsilanen (CH\(_3\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (3) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (4) (--+ Umlagerung zu den entsprechenden Acetoxy(methyl) diorganylsilanen (CH\(_3\)) \(_3\)SiOC(O)CH\(_3\) (5) und CH\(_3\)(C\(_6\)H\(_5\))\(_2\)SiOC(O)CH\(_3\) {6)) sind die Thio-Analoga 9 und 10 thermisch stabil (I-molare Lösungen in C\(_6\)D\(_6\), 30 h bei 180 o C).
N2  - The novel synthesis of the (thioacetoxy-S-methyl)diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (9) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (10) and the (mercaptomethyl) diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)SH (11) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SH (12) is described. The silanes 11 and 12 areeasy to handle, whereas the structurally analogous (hydroxymethyl)diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)OH (1) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OH (2) tend to undergo a base-catalyzed decomposition (formation of oligomeric (polymeric) alkoxysilanes and hydrogen). In cantrast to the thermally unstable (acetoxymethyl)diorganylsilanes (CH\(_3\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (3) and (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (4) (--+ rearrangement to the corresponding acetoxy(methyl)diorganylsilanes (CH\(_3\)) \(_3\)SiOC(O)CH\(_3\) (5) and CH\(_3\)(C\(_6\)H\(_5\))\(_2\)SiOC(O)CH\(_3\) (6)), the thio-analogues 9 and 10 are thermally stable (1 molar solutions in C\(_6\)D\(_6\) , 30 h at 180°C).
KW  - Anorganische Chemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64065
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Fritsche, K.
A1  - Tafel, A.
A1  - Wuttke, F.
T1  - Synthese von racemischem Acetyl(t-butyl)methylphenylsilan und Acetylmethylphenyl[(trimethylsilyl)methyl]silan: Substrate für stereoselektive mikrobielle Reduktionen
KW  - Anorganische Chemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64055
ER  - 
TY  - JOUR
A1  - Polidori, C.
A1  - Massi, M.
A1  - Lambrecht, G.
A1  - Mutschler, E.
A1  - Tacke, Reinhold
A1  - Melchiorre, C.
T1  - Selective antagonists provide evidence that M\(_1\) muscarinic receptors may mediate carbachol-induced drinking in the rat
N2  - The present study served to investigate the ability of seven selective muscarinic antagonists to inhibit carbachol-induced drinking in the rat. The muscarinic antagonists were given by intracerebroventricular (i.c.v.) injection 1 min before the i.c.v. injection of carbachol (1 \(\mu\)g/rat). The M\(_2\) antagonist, methoctramine, was inactive up to 80.3 nmol/rat. The M\(_3\) antagonist, p-fluoro-hexahydro-sila-difenidol, elicited a modest (42%) but statistically significant inhibition of drinking only at 80 nmol/rat. On the other band, the selective M\(_1\) antagonists, (R)-trihexyphenidyl, o-methoxy-sila-hexocyclium and pirenzepine, produced a marked and dose-dependent inhibition of carbachol-induced drinking, their 1050 values being 0.51. 7.36 and 9.31 nmoljrat. Also the M\(_1\)/M\(_3\) antagonists, 4-diphenylacetoxy-Nmethylpiperidine methiodide and hexahydro-sila-difen.idol, were potent inhibitors of carbachol-induced drinking, their ID\(_50\) values (0.28 and 11.09 nmoljrat) being related to their pA\(_2\) values for M1 receptors in rabbi t vas deferens. These data suggest that carbachol-induced drinking may be mediated by activation of muscarinic M\(_1\) receptors.
KW  - Anorganische Chemie
KW  - Carbachol-induced drinking
KW  - Muscarinic receptor antagonists
KW  - Muscarinic receptor subtypes
KW  - Muscarinic M1 receptors; Muscarinic M2 receptors
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64044
ER  - 
TY  - JOUR
A1  - Waelbroeck, M.
A1  - Camus, J.
A1  - Tastenoy, M.
A1  - Lambrecht, G.
A1  - Mutschler, E.
A1  - Tacke, Reinhold
A1  - Christophe, J.
T1  - Stereoselectivity of procyclidine binding to muscarinic receptor subtypes M\(_1\), M\(_2\) and M\(_4\)
N2  - The goals of the present study were: (1) to investigate thc binding properlies oi (R)- and (S)-procyclidine and two aehiral derivatives of muscarinic M\(_1\)• M\(_2\) and M\(_4\) receptor subtypes and (2) to identify the interaetions which allow these receptors to diseriminate between the two stereoisomers. (R)-Procyclidine showed a higher affinity for human neuroblastoma NB-OK 1 muscarinie M\(_1\) and rat striatum musearinie M\(_4\) receptors. a~ compared to rat cardiac M\(_2\) receptors. (S)-Procyclidine had a 130-iold lower affinity than (R)-procyclidine for M\(_1\) and M\(_4\) receptors. and a 40-fold lower affinity for M\(_2\) receptors. Pyrrinol. the aehiral diphenyl derivative with the eyclohexyl g.roup of (S}-procyclidine replaeed by a phenyl group, has an eight-fold lower affinity for M\(_1\) and M\(_4\) receptors. as eompared to (R)-procyclidine, and a three-fold lower affinity for M\(_2\) receptors. Hexahydro-procyclidine. the eorresponding achiral dicyclohexyl compound, had a 10- to 20-fold lower affinity than (R)-procyclidine for the three reeeptors. The inerease in binding free energy, which is observed when the phenyl and eyclohexyl groups of procyelidine are separately replaeed by cyclohexyJ and phenyl groups, respectively. was additive in the ease of M\(_1\)• M\(_2\) and M\(_4\) receptcrs. This indicates that the musearinic reeeptor s!ereoseleetivity was based on the eoexistence of two binding sites, one preferring a phenylrather than eyclohexyl group and the seeond preferring a cyclohexyl rather than a phenyl group. In addition. there were aiso binding sites for the hydroxy moiety and the protonated amino group of the ligands. The greater affinity and stereoselectivity of M\(_1\) and M\(_4\) muscarinic receptors for (R)-procyelidine reflected the better fit of the eyclohexyl group of (R)-procyclidine to the subsite of M\(_1\) and M\(_4\) as compared to M\(_2\) receptors.
KW  - Anorganische Chemie
KW  - Musearlnie M1
KW  - receptors
KW  - Muscarinie M2 receptors
KW  - Musearinic M4 receptors
KW  - Pyrrinol
KW  - Hexahydro-procyclidine
KW  - Muscarinic receptors
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64034
ER  - 
TY  - JOUR
A1  - Rettenmayr, N. M.
A1  - Rodrigues de Miranda, J. F.
A1  - Rijntjes, N. V. M.
A1  - Russel, F. G. M.
A1  - van Ginneken, C. A. M.
A1  - Strohmann, C.
A1  - Tacke, Reinhold
A1  - Lambrecht, G.
A1  - Mutschler, E.
T1  - Pharmacokinetic properties of the antimuscarinic drug [\(^3\)H]-hexahydro-sila-difenidol in the rat
N2  - The pharmacokinetics of tritiated hexahydrosila- difenidol ([\(^3\)H]-HHSiD) were examined in rats. Furthermore, the distribution of radioactivity was studied by means of whole body autoradiography. After i. v. administration of 2.9 mg/kg HHSiD plus [\(^3\)H]-HHSiD to anaesthetized rats bearing a catheter implanted in the ductus choledochus and receiving a mannitol infusion, HHSiD was rapidly distributed and metabolized. Only 5% ofthe radioactivity was recovered in blood after 23 s and 0.4% after 2.5 h. 64% of the plasma radioactivity could be extracted with hexane from the samples taken 23 s after administration. 52% of the radioactivity was eliminated within 2.5 h, 13% by urinary and 39% by biliary excretion. Following oral administration of 8.6 mg/kg HHSiD plus [\(^3\)H]-HHSiD there was an absorption of approximately one fourth of the administered radioactivity within 4 h. By means of whole body autoradiography (i. v. injection) as well as by tissue distribution measurement the highest Ievels of radioactivity were found in bile, urine, lung, kidney, adrenals, liver and .pancreas. Thus, after i. v. administration to rats HHSiD is rather quickly distributed, metabolized and excreted. This explains its low antimuscarinic potency in vivo.
KW  - Anorganische Chemie
KW  - Pharmacokinetics
KW  - [3H]-Hexahydro-siladifenidol
KW  - Sila-drug
KW  - Rat
KW  - Autoradiography
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64022
ER  - 
TY  - JOUR
A1  - Tacke, Reinhold
A1  - Hengelsberg, H.
A1  - Zilch, H.
A1  - Stumpf, B.
T1  - Enantioselective microbial reduction of 1,1-dimethyl-1-sila-cyclohexan-2-one with growing cells of the yeast Kloeckera corticis (ATCC 20109)
N2  - (R)-1,1-Dimethyl-1-sila-cyclohexan-2-ol [(R)-2] was prepared by enantioselective microbial reduction of 1,1-dimethyl-1-sila-cyclohexan-2-one (1) with growing cells of the yeast Kloeckera corticis (ATCC 20109). At a substrate concentration of 0.5 g/1 (temperature 27° C, incubation time 16 h), (R}-2 was obtained on a preparative scale in 60% yield and with an enantiomeric purity of 92% ee. Repeated recrystallization of the biotransformation product from n-hexane raised the enantiomeric purity to 99% ee.
KW  - Anorganische Chemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64010
ER  - 
TY  - JOUR
A1  - Feifel, R.
A1  - Wagner-Röder, M.
A1  - Strohmann, C.
A1  - Tacke, Reinhold
A1  - Waelbroeck, M.
A1  - Christophe, J.
A1  - Mutschler, E.
A1  - Lambrecht, G.
T1  - Stereoselective inhibition of muscarinic receptor subtypes by the enantiomers of hexahydro-difenidol and acetylenic analogues
N2  - 1 Tbc affinities of the (R)- and (S)-enantiomers of hexahydro-difenidol (1) and its acetylenie analogues hexbutinol (2), hexbutinol methiodide (3) and p-fluoro-hexbutinol (4) (stereochemieal purity > 99.8%) for musearlnie receptors in rabbit vas deferens (M1), guinea-pig atria (M2) and guinea-pig ileum (M3) were measured by dose-ratio experiments. 2 The (R)-enantiomers consistently showed higher aßinities than the (S)-isomers. The stereosclectivity ratios [(R)/(S)] wcrc greatest with thc enantiomers of 1 (vas deferens: 550; ilcum: 191; atria: 17) and least with thosc ofthc p-Fluoro-analogue 4 (vas defercns: 34; ileum: 8.5; atria: 1.7). 3 The enantiomerie potency ratios for compounds 1-4 were highest in rabbit vas deferens, intermediate in guinea-pig ileum and much less in guinea-pig atria. Thus, these ratios may serve as a predietor of muscarinic receptor subtype identity. 4 (S)-p-Fluoro-hexbutinol [(S)-4] showed a novel receptor selectivity profile with preference for M\(_3\) receptors: M\(_3\) > M\(_2\) \(\geq\) M\(_1\)• 5 These results do not conform to Pfeiffer's rule that aetivity differences between enantiomers are greater with more potent compounds.
KW  - Anorganische Chemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64002
ER  -