Reduction by a Model of NAD(P)H. 34. Substituent Effect on Asymmetric Reduction of Trifluoroacetophenones

Substituted and unsubstituted α,α,α-trifluoroacetophenones were reduced by a chiral NAD(P)H-model (RR-Me2PNPH). Both electron-releasing and -withdrawing substituents give better optical yields than unsubstitued compound. The result has been interpreted in terms of three-step mechanism which involves initial electron-transfer process.