Reduction by a Model of NAD(P)H. 33. Steric and Electronic Effects on Asymmetric Reduction of 2-Acylpyridines

Article abstract of DOI:10.1246/bcsj.54.3482

Series of alkyl and fluorinated alkyl 2-pyridynyl ketones have been reduced by a chiral NAD(P)H-model (Me2PNPH) in the presence of magnesium ion in acetonitrile.Optical yield decreases in the order of substituent: CH3 > C2H5 > C(CH3)3 > CH(CH3)2 and CH3 > CH2F > CHF2 > CF3.The results have been interpreted in terms of conformation of the substrates for alkyl 2-pyridynyl ketones and of electronic competitional effect between two substituents for fluorinated alkyl 2-pyridynyl ketones.Magnesium ion freezes intermolecular arrangement at the transition state of the reduction.