Figure 1: Pd-catalyzed carbonylation of C(sp³)–H bonds.

(a) Previous reports on Pd-catalyzed carbonylation of methyl C(sp³)–H bonds with carbon monoxide through a Pd(0)/Pd(II) catalytic cycle. (b) Our work on Pd-catalyzed alkoxycarbonylation of unactivated C(sp³)–H bonds with alkyl chloroformates through a Pd(II)/Pd(IV) catalytic cycle.