Abstract: This study presents a visible-light-induced photocatalytic strategy employing triphenylphosphine-promoted deoxygenative amidation for dipeptide synthesis. Utilizing an iridium metal complex as the catalyst under blue light irradiation, N-protected amino acids generate acyl radicals that subsequently couple with amino acid esters to form dipeptides. The method demonstrates high product yields and exceptional diastereoselectivity. This protocol features cost-effective reagents, mild reaction conditions, operational simplicity, environmental friendliness, high efficiency, and excellent reproducibility, with the entire process completable within an 8-hour timeframe.

Key words: Visible light catalysis, Dipeptide, Deoxygenative amidation, Iridium complex, Triphenylphosphine