@article{TackeWagnerBrakmannetal.1993, author = {Tacke, Reinhold and Wagner, S. A. and Brakmann, S. and Wuttke, F. and Eilert, U. and Fischer, L. and Syldatk, C.}, title = {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.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64299}, year = {1993}, abstract = {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.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeLopezMrasSperlichetal.1993, author = {Tacke, Reinhold and Lopez-Mras, A. and Sperlich, J. and Strohmann, C. and Kuhs, W. F. and Mattern, G. and Sebald, A.}, title = {Neue zwitterionische \(\lambda_5\)-Spirosilicate: Synthesen, Einkristall-R{\"o}ntgenstrukturanalysen und Festk{\"o}rper-NMR-Untersuchungen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64251}, year = {1993}, abstract = {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 d{\"u}fraction. 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.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeLopezMrasSheldricketal.1993, author = {Tacke, Reinhold and Lopez-Mras, A. and Sheldrick, W. S. and Sebald, A.}, title = {Synthesen, Einkristall-R{\"o}ntgenstrukturanalysen und \(^{29}\)Si-Festk{\"o}rper-NMR-Untersuchungen eines zwitter- ionischen \(\lambda_5\)-Spirosilicats und eines k{\"a}figartigen Octa(silasesquioxans) : [Professor Hartmut B{\"a}rnighausen zum 60. Geburtstage gewidmet]}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64243}, year = {1993}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {de} } @article{TackeLopezMrasBechtetal.1993, author = {Tacke, Reinhold and Lopez-Mras, A. and Becht, J. and Sheldrick, W. S.}, title = {Synthese sowie Kristall- und Molek{\"u}lstruktur von Tetrafluoro[2-(pyrrolidinio)ethyl]silicat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64269}, year = {1993}, abstract = {Das zwitterionische Tctratluoro[2-(pyrrolidinio) ethyl]silicat (4) wurde durch Reaktion von Trimethoxy( 2-pyrrolidinoethyl)silan (5) mit Fluorwasserstoff in einem Ethanol/Flußs{\"a}ure-Gemisch bei 0 °C synthetisiert. Die Kristall- und Molek{\"u}lstruktur von 4 wurde bei - 100 °C mittels einer Einkristall-R{\"o}ntgenstrukturanalyse untersucht. Außerdem wurde 4 durch NMR-Untersuchungen in L{\"o}sung charakterisiert (CD\(_3\)CN: \(^1\)H, \(^{13}\)C).}, subject = {Anorganische Chemie}, language = {de} } @article{TackeBechtLopezMrasetal.1993, author = {Tacke, Reinhold and Becht, J. and Lopez-Mras, A. and Sheldrick, W. S. and Sebald, A.}, title = {Syntheses, X-ray crystal structure analyses, and solid-state NMR studies of some zwitterionic organofluorosilicates}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64272}, year = {1993}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{SperlichBechtMuehleisenetal.1993, author = {Sperlich, J{\"o}rg and Becht, Joachim and M{\"u}hleisen, Mathias and Wagner, Stephan A. and Mattern, G{\"u}nter and Tacke, Reinhold}, title = {Zwitterionische Bis[vic-arendiolato(2-)][(morpholinio)alkyl]silicate: Synthese sowie strukturelle Charakterisierung in L{\"o}sung und im Kristall}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73153}, year = {1993}, abstract = {No abstract available.}, subject = {Silicate}, language = {de} } @article{EltzeUllrichMutschleretal.1993, author = {Eltze, M. and Ullrich, B. and Mutschler, E. and Moser, U. and Bungardt, E. and Friebe, T. and Gubitz, C. and Tacke, Reinhold and Lambrecht, G.}, title = {Characterization of muscarinic receptors mediating vasodilation in rat perfused kidney}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64283}, year = {1993}, abstract = {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.}, subject = {Anorganische Chemie}, language = {en} }