Cobalt-Catalyzed Hydrogenation of Esters to Alcohols: Unexpected Reactivity Trend Indicates Ester Enolate Intermediacy

The atom‐efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious‐metal‐based catalysts, with few exceptions. Presented here is the first cobalt‐catalyzed hydrogenation of esters to the corresponding alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates. Getting involved: The atom‐efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious‐metal‐based catalysts. Presented here is the first cobalt‐catalyzed hydrogenation of esters to alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates.