Non-innocent Character of Oxyanions in Ruthenium Metathesis Catalysts
摘要:
The synthesis, characterization, reactivity, and selectivity of six novel ruthenium metathesis catalysts containing oxyanions as ligands are described. A drop in chemoselectivity and/or reactivity in alternating ring-opening metathesis polymerization of norbornene and cyclooctene for catalysts with nitrate, acetate, and benzoate ligands (i.e., catalysts 7, 8, and 10a) compared to the parent complex bearing chloride as a ligand (513) is observed, while catalysts with trifluoroacetate, methylbenzoate, and triisopropylbenzoate ligands (i.e., catalysts 9, 10b, and 10c) exhibit the expected activities and chemoselectivities. A model accounting for the aforementioned observations is based on a chelating effect of oxyanion ligands in these complexes and is supported by NMR data, crystal structures of the new complexes, and DFT calculations. Through comparison of selectivity and reactivity in copolymerizations with NMR and X-ray structures, we have uncovered correlations that serve as predictive tools for catalyst design.
Synthesis of Dibenzofurans via Palladium-Catalyzed Phenol-Directed C–H Activation/C–O Cyclization
摘要:
A practical, Pd(0)/Pd(II)-catalyzed reaction was developed for phenol-directed C-H activation/C-O cyclization using air as an oxidant. The turnover-limiting step of the process was found to be C-O reductive elimination instead of C-H activation. This reaction can tolerate a variety of functional groups and is complementary to the previous methods for the synthesis of substituted dibenzofurans.
Diastereoselective synthesis of α-bromo amides leading to diastereomerically enriched α-amino-, α-hydroxy- and α-thiocarboxylic acid derivatives
作者:By Robert S Ward、Andrew Pelter、Dominique Goubet、Martyn C Pritchard
DOI:10.1016/0957-4166(95)00032-k
日期:1995.2
prepared diastereoselectively starting from racemic α-bromo acids, and undergo epimerisation under appropriate conditions leading to an enhanced d.e.. By reacting the individual isomers or the mixture of diastereoisomers with a suitable nucleophile it is possible to obtain α-substituted carboxylic acids, including α-amino- α-hydroxy- and α-thiocarboxylic acid derivatives, in diastereomerically enriched
ORGANIC COMPOSITION, AND ORGANIC OPTOELECTRONIC ELEMENT AND DISPLAY DEVICE
申请人:Samsung SDI Co., Ltd.
公开号:EP3020708A1
公开(公告)日:2016-05-18
Disclosed are an organic compound represented by a combination of a moiety represented by Chemical Formula 1 and a moiety represented by Chemical Formula 2, an organic optoelectronic device and a display device including the organic compound.
Organic composition, and organic optoelectronic element and display device
申请人:SAMSUNG SDI CO., LTD.
公开号:US10032990B2
公开(公告)日:2018-07-24
Disclosed are an organic compound represented by a combination of a moiety represented by Chemical Formula 1 and a moiety represented by Chemical Formula 2, an organic optoelectronic device and a display device including the organic compound.