Late-Stage Diversification of Peptides via Pd-Catalyzed Site-Selective δ-C(sp 2 )-H Fluorination and Amination.

Site-selective C-H fluorination is an attractive strategy for directly transforming inert C-H bonds into C-F bonds, yet it remains a significant challenge. Herein, we have developed an efficient and versatile strategy for site-selective fluorination and amination of phenylalanine-containing peptides via late-stage Pd-catalyzed δ-C(sp 2 )-H activation, providing a valuable tool for the in situ synthesis of fluorinated indoline scaffolds within peptides.