Backbone-enabled modification of peptides with benzoquinone via palladium-catalyzed δ-C(sp 2 )-H functionalization.

Backbone-enabled site-selective modification of peptides with benzoquinone via Pd-catalyzed δ-C(sp 2 )-H functionalization has been achieved. The amide groups of peptides serve as internal directional groups, facilitating C-H functionalization through a kinetically less favored six-membered palladacycle. This methodology presents novel opportunities for the late-stage site-selective diversification of peptides.