Excited-state palladium-catalysed reductive alkylation of imines: scope and mechanism

Chem Sci. 2022 Jul 7;13(29):8583-8589. doi: 10.1039/d2sc02363f. eCollection 2022 Jul 29.

Abstract

Palladium catalysis induced by visible-light irradiation is a promising tool for promoting unusual chemical transformations. We describe the development of excited-state palladium-catalyzed reductive alkylation of imines with alkyl bromides. The new methodology shows broad functional group tolerance and can additionally be applied in the direct three-component reaction of aldehydes, anilines, and alkyl bromides to give the alkyl amines under mild reaction conditions. Time-resolved photoluminescence experiments allowed the determination of the excited-state reaction kinetics and indicate that the reaction is proceeding via the inner-sphere electron transfer mechanism.