Visible-Light-Driven, Copper-Catalyzed Decarboxylative C(sp3 )-H Alkylation of Glycine and Peptides

Abstract

Despite a well-developed and growing body of work in Cu catalysis, the potential of Cu to serve as a photocatalyst remains underexplored. Reported herein is the first example of visible-light-induced Cu-catalyzed decarboxylative C(sp³ )-H alkylation of glycine for preparing α-alkylated unnatural α-amino acids. It merits mentioning that the mild conditions and the good functional-group tolerance allow the modification of peptides using this method. The mechanistic studies revealed that a radical-radical coupling pathway is involved in the reaction.

Keywords: copper; cross-coupling; peptides; photochemistry; radicals.