Visible‐Light‐Promoted C(sp3)‐H Alkylation by Intermolecular Charge Transfer: Preparation of Unnatural α‐Amino Acids and Late‐stage Modification of Peptides

Disclosed herein is the visible-light-promoted deaminative C(sp(3) )-H alkylation of glycine and peptides using Katritzky salts as electrophiles. Simple reaction conditions and excellent functional-group tolerance provide a general strategy for the efficient preparation of unnatural alpha-amino acids and precise modification of peptides with unnatural alpha-amino-acid residues. Mechanistic studies suggest that visible-light-promoted intermolecular charge transfer within a glycine-Katritzky salt electron donor-acceptor (EDA) complex induces a single-electron transfer process without the assistance of photocatalyst.