Decarbonylation of benzaldehydes by dual photoorgano-cobalt catalysis.

We report a mild alternative to thermally-driven noble-metal catalyzed decarbonylation protocols for the defunctionalization of benzaldehydes in short reaction times. Our cooperative photocatalytic system involves thioxanthone as an inexpensive HAT-agent and a cobalt complex required for selective C(sp 2 )-C(sp 2 ) bond cleavage. The generated acyl and phenyl intermediates are postulated to be stabilized as cobalt complexes.