Studies on the 1,2-Migrations in Pd-Catalyzed Negishi Couplings with JosiPhos Ligands
作者:Anders T. Lindhardt、Thomas M. Gøgsig、Troels Skrydstrup
DOI:10.1021/jo801824e
日期:2009.1.2
cross-coupling, which is promoted by palladium catalyst systems generated with JosiPhos ligands. Several of the factors that were demonstrated to be important for the 1,2-migration include (1) the nucleophilicity of the organometallic reagent, which possibly influences the transmetalation step in direct competition with the intermediate β-hydride elimination of the alkenyl Pd(II) species; (2) the structural
ACRYLONITRILE DERIVATIVES, LIQUID-CRYSTAL COMPOSITION, AND LIQUID-CRYSTAL DISPLAY DEVICE
申请人:CHISSO CORPORATION
公开号:EP0820983A1
公开(公告)日:1998-01-28
Acrylonitrile derivatives represented by general formula (I), a liquid-crystal composition containing the above compound and being improved in viscosity, optical anisotropy and so forth, and a liquid-crystal display device prepared from the composition, wherein A1 to A3 represent each phenylene, cyclohexylene, dioxane or pyrimidine; R1 represents cyano, halogeno, alkyl, alkoxy, etc.; and R2 represents a group represented by general formula (II) or (III).