Synergistic Cobalt and Cerium <scp>LMCT</scp> Photocatalysis for Decarboxylative Heck Type Reaction Facilitated by Efficient Acceptorless Dehydrogenation

Comprehensive Summary The direct construction of C(sp 3 )−C(sp 2 ) bonds from operationally convenient, synthetically versatile, and readily accessible building blocks serves as a key driving force for innovation in synthetic organic chemistry. These scaffolds enhance drug properties, facilitating the development and clinical translation of lead compounds. In this work, we report the first use of the synergistic effect between Co and Ce LMCT catalysis, presenting an effective photocatalytic strategy for the decarboxylative Heck type coupling reaction of primary, secondary, and tertiary aliphatic carboxylic acids. Under mild conditions, this method achieves the effective coupling of C(sp 3 ) and C(sp 2 ) motifs, demonstrating excellent functional group tolerance and offering significant potential for the late‐stage modification of bioactive carboxylic acids. Notably, this transformation proceeds without the need for external oxidants or pre functionalization of the carboxylic acids, with H 2 and CO 2 as the sole byproducts.