Ammonia-Borane Dependent Transfer Hydrogenation of Carboxylic Esters to Primary Alcohols

Abstract

Here, we present a user-friendly protocol that uses bench-stable NH 3 • BH 3 (AB) as the hydrogen transfer agent for the reduction of both aromatic and aliphatic esters without an external catalyst and base, delivering a structurally diverse array of primary alcohols (80−98% yields). The broad functional-group tolerance (halogen, boronic ester, −NO 2 , −OH, etc.) under environmentally acceptable conditions implies high practical utility. Further, a tandem catalytic conversion of a plastic waste polyethylene terephthalate (PET) bottle to 1,4-benzenedimethanol including fatty esters into respective fatty alcohols was shown.