Pd‐Catalyzed Umpolung of η3‐Benzylpalladium Enabled the Construction of All‐Carbon α‐Vinyl Quaternary Aldehydes

Abstract A Pd‐catalyzed decarboxylative approach for the construction of 2‐allyl‐2,2‐diarylacetaldehydes via dearomative umpolung strategy is reported. The reaction is applicable to a number of cyclic carbonates or allylic acetates featuring with different functional groups. These reactions could be performed in a gram‐scale but without loss of the reaction efficiency. The control experiments suggest that the reaction proceeds though a palladium catalyzed dearomative decarboxylation step followed by an umpolung nucleophilic attack. magnified image