Harnessing Photoredox Catalysis to Access <i>β</i> ‐Ketoamino Esters from 3‐(2‐Isocyanoethyl)indoles

The direct and selective modification of glycine derivatives has garnered significant attention interest in recent years, owing to the prevalence of the glycine motif in bioactive peptides. In this study, we present the first example of direct CC bond formation via carbonylation of glycine ester with 3‐(2‐Isocyanoethyl)indoles to furnish β ‐ketoamino ester derivatives. This transformation proceeds efficiently under visible‐light irradiation using Rose Bengal B as an organic photosensitizer, exhibits broad functional group compatibility, and delivers the desired products in 60%–72% yields. Preliminary mechanistic investigations suggest that the reaction proceeds through a reductive quenching pathway, in which an in situ ‐ generated iminium ion intermediate undergoes nucleophilic addition to afford the final products. Overall, this strategy provides a practical, efficient, and straightforward approach to the synthesis of β ‐ketoamino ester derivatives.