TY - JOUR A1 - Christl, Manfred A1 - Lang, Reinhard A1 - Herzog, Clemens A1 - Stangl, Roland A1 - Peters, Karl A1 - Peters, Eva-Maria A1 - Schnering, Hans Georg von T1 - Reaktion von Homobenzvalen mit Tetracyanethylen : Bildung eines Tetracyandihydrobarbaralan- und eines Tetracyancyclopropan-Derivats N2 - In den Reaktionen von Tetracyanethylen (TCNE) und 5,6-Dichlor-2,3-dicyan-p-benzochinon mit Benzvalen haben wir kürzlich die ersten Beispiele für die lange gesuchte einstufige 1,4-Cycloaddition eines Alkens an ein Vinylcyclopropan gcfunden(I~J. Sie ist als [(.,2.+.2s)+ 112J-Prozeß der Dicls-Alder-Addition nahe verwandtllbl. Allerdings entsteht das betreffende TCNE-Addukt, ein Dihydrosemibullvalen-Derivat, nur in einer Ausbeute von wenigen Prozent. Die Hauptprodukte gehen aus einer Zwitterionischen Zwischenstufe hervor, die durch Anlagerung von TCNE an die Benzvalen-n-Bindung resultiert. Professor Rolf Huisgen zum 65. Geburtstag gewidmet KW - Chemie KW - Homobenzvalene Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31839 ER - TY - JOUR A1 - Schreck, Michael A1 - Christl, Manfred T1 - Generation and Interception of 1-Oxa-3,4-cyclohexadiene N2 - No abstract available KW - Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31601 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Martin T1 - Generation and interception of 1-OXA-2,3-Cyclohexadiene and 1,2,4-Cyclohexatriene N2 - The cycloadducts 6 and 7 of tricyc1o[4.1.0.0 2 ,7)hepta- 3,4-diene (~) with styrene and 1,3-butadiene rearrange to unusual products on thermolysis, namely the cycloheptatriene derivatives ~ and 10. 1-0xa-3,4-cyclohexadiene (20) is generated smoothly from 6,6-dichloro-3-oxabicyclo[3.1.0]hexane (22) and n-butyllithium. 1-0xa-2,3-cyclohexadiene (11) is formed from 6-exo-bromo-6-endo-fluoro-2-oxabicyclo[ 3.1.0]hexane (30) and methyllithium. In the presence of activated olefins, this reaction provides an efficient route to 28 and 33 - 38, the trapping products of 21. Interestingly, [2+2]-cycloadditions do not take place at the same double bond of 21 as [4+2]-cycloadditions. The reactions of 1,3-cyclopentadiene and indene with bromofluorocarbene afford 6-exo-bromo-6-endo-fluorobicyclo[3.1.0]hex-2-ene (50) and its benzo derivative ~, respectively. On treatment of these compounds with methyl lithium in the presence of styrene, the interception products 53 and 47 of 1,2,4-cyc10- hexatriene (44) and its benzo derivative 43, respectively, are formed in good yields. KW - Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-56566 ER - TY - JOUR A1 - Schreck, Michael A1 - Christl, Manfred T1 - Freisetzung und Abfangreaktionen von 1-Oxa-3,4-cyclohexadien N2 - No abstract available KW - Chemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31597 ER - TY - JOUR A1 - Gleiter, Rolf A1 - Bischof, Peter A1 - Christl, Manfred T1 - Electronic Structure of Octavalene : Photoelectron Spectroscopic Investigations N2 - The He I photoelectron (PE) spectra of octavalene (5) as weil as its hydrogenated products 6-8 have been investigated. The assignment given is based on an empirical comparison of 5-8 with related compounds, a ZDO model, and semiempirical and ab initio calculations. Within the ZDO model the interaction between the buta.diene moiety and the bicyclobutane fragment of 5 is described by a resonance integral of -2.3 eV. The orbitalsequence of 5 is found tobe 2a\(_2\) (\(\pi\)-\(\sigma\)), 9a\(_1\) (\(\sigma\)), 3b1 (\(\pi\) - \(\sigma\)), 1a\(_2\) (\(\sigma\) + \(\pi\)), 2b\(_1\) (\(\sigma\) + \(\pi\)). KW - Chemie KW - Octavalen KW - Photoelektron Y1 - 1986 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31588 ER - TY - JOUR A1 - Homann, Arne A1 - Timm, Malte A1 - Seibel, Jürgen T1 - Chemo-enzymatic synthesis and in vitro cytokine profiling of tailor-made oligofructosides N2 - Background It is well known that carbohydrates play fundamental roles in cell signaling and infection processes as well as tumor formation and progression. However, the interaction pathways and cellular receptors targeted by carbohydrates and glycoconjugates remain poorly examined and understood. This lack of research stems, at least to a major part, from accessibility problems of large, branched oligosaccharides. Results To test glycan - cell interactions in vitro, a variety of tailored oligosaccharides was synthesized chemo-enzymatically. Glycosyltransferases from the GRAS organisms Bacillus megaterium (SacB) and Aspergillus niger (Suc1) were used in this study. Substrate engineering of these glycosyltransferases generally acting on sucrose leads to the controlled formation of novel tailored di-, tri- and tetrasaccharides. Already industrially used as prebiotics in functional food, the immunogenic potential of novel oligosaccharides was characterized in this study. A differential secretion of CXCL8 and CCL2 was observed upon oligosaccharide co-cultivation with colorectal epithelial Caco-2 cells. Conclusion Pure carbohydrates are able to stimulate a cytokine response in human endothelial cells in vitro. The type and amount of cytokine secretion depends on the type of co-cultivated oligosaccharide. KW - Chemie KW - Oligofructoside KW - Glycosyltransferase KW - Suc1 KW - Aspergillus niger KW - SacB KW - Bacillus megaterium KW - CXCL8 (IL-8) KW - CCL2 (MCP-1) KW - Caco-2 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76393 ER - TY - JOUR A1 - Menekse, Kaan A1 - Renner, Rebecca A1 - Mahlmeister, Bernhard A1 - Stolte, Matthias A1 - Würthner, Frank T1 - Bowl-shaped naphthalimide-annulated corannulene as nonfullerene acceptor in organic solar cells JF - Organic Materials N2 - An electron-poor bowl-shaped naphthalimide-annulated corannulene with branched alkyl residues in the imide position was synthesized by a palladium-catalyzed cross-coupling annulation sequence. This dipolar compound exhibits strong absorption in the visible range along with a low-lying LUMO level at –3.85 eV, enabling n-type charge transport in organic thin-film transistors. Furthermore, we processed inverted bulk-heterojunction solar cells in combination with the two donor polymers PCE–10 and PM6 to achieve open-circuit voltages up to 1.04 V. By using a blend of the self-assembled naphthalimide-annulated corannulene and PCE–10, we were able to obtain a power conversion efficiency of up to 2.1%, which is to the best of our knowledge the highest reported value for a corannulene-based organic solar cell to date. KW - Chemie KW - corannulene KW - nonfullerene acceptors KW - curved π-systems KW - bulk-heterojunction solar cells KW - aggregation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299095 UR - https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0040-1714283 SN - 2625-1825 VL - 2 IS - 3 ER - TY - JOUR A1 - Gleiter, Rolf A1 - Bischof, Peter A1 - Gubernator, Klaus A1 - Christl, Manfred A1 - Schwager, Luis A1 - Vogel, Pierre T1 - 2,3-Bis(methylene)bicyclo[2.1.1]hexane and 3,4-Bis(methylene)tricyclo[3.1.0.0\(^{2,6}\)]hexane : Interaction between a π System and a Cyclobutane or Bicyclobutane Moiety N2 - The He (I) photoelectron spectra of 2-bicyclo[2.1.l]hexene (1), 2,3-bis(methylene)bicyclo[2.1.l]hexane (3), and 3,4-bis(methylene)tricyclo[3.l.O.0\(^{2.6}\)]hexane (4) have been investigated. The assignment given is based on a ZDO model and semiempirical calculations. Tagether with the PE data of benzvalene (2), the reported data allow a comparison between 1-2 and 3-4. This yields a measure of the interactions between 8 cyclobutane or 8 bicyclobutane moiety and a double bond system within a ZDO model. The resonance integral found in the case of 1 and 3 amounts to -1.9 eV, that for 2 and 4, to -2.3 eV. The investigations furthermore reveal that the electronic factors which contribute to the higher reactivity of the bicyclobutane compounds amount to 5 kcal/mol. KW - Chemie Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31845 ER - TY - JOUR A1 - Christl, Manfred A1 - Schreck, Michael T1 - 1,2,3,5,8,8a-Hexahydronaphthalin aus 1,2-Cyclohexadien N2 - Reaktionen von 1,3-Butadien und einigen seiner Methylderivate mit 1a und 1- Methyl-1,2-cyclohexadien 1b sowie den Übergang der [2 + 2]-Cycloaddukte 2 und 3 in das bisher unbekannte 1,2,3,5,8,8a-HexahydronaphthaJin 4a und einige seiner Methylderivate KW - Chemie KW - Butadien Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31656 ER -