Reductively Stable Platinum Catalyst Enabling Metallaphotoredox Reductive Allylation of Ketones, Aldehydes, and Imines

This work demonstrates the catalytic reductive allylation of ketones, aldehydes, and imines using a synergistic platinum/photoredox catalyst system. Notably, this method is applicable even to acetophenone derivatives, affording homoallylic alcohols that are otherwise difficult to obtain using conventional photoredox methodologies. A platinum complex exhibited remarkable catalytic activity in this allylation reaction, whereas palladium and nickel‐based compounds either failed to catalyze the reaction or displayed significantly lower efficiency. Mechanistic investigations suggest that the reductive stability of the (π‐allyl)platinum(II) complex, which enables the selective reduction of substrates by a photoredox catalyst, is a key feature of this widely applicable reaction.