Lighting up peptides: direct dehydroalanine formation from diselenides via Rose Bengal photocatalysis

Abstract

A visible-light-driven method for the site-selective conversion of diselenide-containing peptides to dehydroalanine (Dha) is presented. Using Rose Bengal as a photosensitizer in aqueous conditions, this photocatalytic process proceeds via oxidative cleavage of the Se–Se bond followed by β-elimination to afford Dha with high yield and chemoselectivity. This mild and bioorthogonal strategy enables downstream peptide functionalization and offers a practical route for post-synthetic peptide editing.