Lewis Acid-Free Ynoate-Mediated Chemoselective Reduction of Carboxylic Acids to Primary Alcohols

摘要

We present an economical and facile catalytic reduction process of carboxylic acids for the synthesis of alcohols.This pyridine-catalyzed strategy operates through addition of carboxylic acids with methyl propiolate followed by NaBH4 reduction or unexpected ester exchange,providing the corresponding primary alcohols and esters,respectively.A range of carboxylic acids bearing other reductive groups(e.g.,halogen,cyano,nitro,ester and double bond)are accessed with uniformly high chemoselectivity.The use of environmentally benign,convenient and safe procedure also makes this catalytic protocol attractive for practical application.