PPh3-catalyzed chemoselective reduction of aldehydes to alcohols

Reduction of aldehydes to alcohols is a fundamental organic transformation, typically achieved through metal-catalyzed reductions or by the use of hydride-based reagents. However, these conventional methods often go through harsh conditions with expensive catalysts and additional reductants, limiting their broader applications. In this study, for the first time we introduce an efficient, metal-free reduction strategy using triphenylphosphine (PPh3) and KOtBu in MeOH. This method exhibits broad functional group tolerance, mild environment and selectivity in reducing aldehydes even in the presence of other reactive functionalities (NO2, CN, ketone, etc.). Key features highlight this novel approach with practicality, scalability to gram scales and excellent yields for the reduction of varied aldehydes to alcohols (30 examples; 65–95 % Yields).