Efficient Palladium-Catalyzed Aerobic Oxidative Carbocyclization to Seven-Membered Heterocycles.

ABSTRACT: The use of molecular oxygen in palladium-catalyzed oxidation reactions is highly widespread in organic chemistry. However, the direct reoxidation of palladium by O₂ is often kinetically unfavored, thus leading the deactivation of the palladium catalyst during the catalytic cycle. In the present work, we report a highly selective palladium-catalyzed carbocyclization of bisallenes to seven-membered heterocycles under atmospheric pressure of O₂ . The use of a homogenous hybrid catalyst (Co(salophen)-HQ, HQ=hydroquinone) significantly promotes efficient electron transfer between the palladium catalyst and O₂ through a low-energy pathway. This aerobic oxidative transformation shows broad substrate scope and functional group compatibility and allowed the preparation of O-containing seven-membered rings in good yields in most cases.

SUBMITTER: Liu J 

PROVIDER: S-EPMC7894550 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature