1,2-Reduction of α,β-unsaturated hydrazones using dimethylamine–borane/p-toluenesulfonic acid: an easy route to allyl hydrazines
作者:Maria E Casarini、Franco Ghelfi、Emanuela Libertini、Ugo M Pagnoni、Andrew F Parsons
DOI:10.1016/s0040-4020(02)00914-6
日期:2002.9
alpha,beta-Unsaturated hydrazones can be easily converted into N-allyl hydrazines by reaction with dimethylamine-borane/p-toluenesulfonic acid under mild reaction conditions. The reduction works well for N'-allyhydrazides but N'-allyl-N,N-dimethylhydrazines are rapidly reoxidised by air and so need to be manipulated under an inert atmosphere prior to M-acylation. Competitive conjugate reduction can also be observed and the regioselectivity of the dimethylamine-borane attack is determined by steric and/or electronic factors. The procedure is also effective for the C=N reduction of unconjugated hydrazones. (C) 2002 Elsevier Science Ltd. All rights reserved.