The radical-radical cross-coupling of alkyl carboxylic acids and organoborons

Carbon–carbon bond-forming reactions are fundamental in organic chemistry, constructing molecular backbones. Despite over a century of research on radicals from carboxylic acids and boronic acids, efficient cross-coupling between these species has not been achieved. Here, we revisit radical-radical cross-coupling to enable the first direct coupling of carboxylic and boronic acids to form alkyl-alkyl C–C bonds using abundant precursors. This breakthrough is enabled by integrating redox-matched alternating polarity electrolysis with controlled activation of redox-active species, ensuring high reactivity, selectivity, and broad scope. This radical-radical cross-coupling strategy opens new directions in C–C bond-forming transformations in organic synthesis.