Cobalt-Catalyzed Intramolecular Hydroacylation Involving Cyclopropane Cleavage

Article abstract of DOI:10.1002/chem.202001223

A simple cobalt-diphosphine catalyst has been found to efficiently promote intramolecular cyclization of ortho-cyclopropylvinyl- and cyclopropylidenemethyl-substituted benzaldehydes into benzocyclooctadienone and benzocycloheptadienone derivatives, respectively. This ring-opening hydroacylation likely involves aldehyde C?H oxidative addition, olefin insertion, cyclopropane cleavage by β-carbon elimination, and C?C bond-forming reductive elimination, as was supported by mechanistic experiments and DFT calculations.