Enantioselective alpha-arylation of ketones with aryl triflates catalyzed by difluorphos complexes of palladium and nickel.

ABSTRACT: The asymmetric alpha-arylation of ketones with aryl triflates is described, and the use of this electrophile with nickel and palladium catalysts containing a segphos derivative increases substantially the scope of highly enantioselective arylations of ketone enolates. The combination of aryl triflates as reactant, difluorphos as ligand, palladium catalysts for reactions of electron-neutral or electron-rich aryl triflates, and nickel catalysts for reactions of electron-poor aryl triflates led to a series of alpha-arylations of tetralone, indanone, cyclopentanone, and cyclohexanone derivatives. Enantioselectivities ranged from 70% to 98% with 10 examples over 90%. Systematic studies on these alpha-arylations have revealed a number of factors that affect enantioselectivity. Ligands containing

SUBMITTER: Liao X 

PROVIDER: S-EPMC2551326 | biostudies-literature | 2008 Jan

REPOSITORIES: biostudies-literature