B(C6F5)3-Catalyzed transfer hydrogenation of esters and organic carbonates towards alcohols with ammonia borane.

Herein, we report an efficient metal-free system for the transfer hydrogenation of esters and carbonates by-passing the otherwise ubiquitous formation of transesterification side-products. The Lewis acid B(C6F5)3 is used as catalyst and ammonia borane as hydrogen donor. This methodology shows broad substrate scope and functional group tolerance in excellent yields at very mild conditions.