Asymmetric Suzuki Cross-Couplings of Activated Secondary Alkyl Electrophiles: Arylations of Racemic alpha-Chloroamides

作者:Lundin Pamela M; Fu Gregory C*
来源:Journal of the American Chemical Society, 2010, 132(32): 11027-11029.
DOI:10.1021/ja105148g

摘要

A nickel-catalyzed stereoconvergent method for the enantioselective Suzuki arylation of racemic alpha-chloroamides has been developed. This process provides a unique example of an asymmetric arylation of an alpha-haloamide, an enantioselective arylation of an alpha-chlorocarbonyl compound, and an asymmetric Suzuki reaction with an activated alkyl electrophile or an arylboron reagent. The method is also applicable to the corresponding enantioselective cross-coupling of alpha-bromoamides. The coupling products can be transformed without racemization into enantio-enriched alpha-arylcarboxylic acids and primary alcohols. A modest kinetic resolution of the alpha-chloroamide was observed; a mechanistic study indicated that the selectivity may reflect discrimination by the chiral catalyst of the two enantiomeric alpha-chloroamides in an irreversible oxidative-addition process.

  • 出版日期2010-8-18