Rh(III)-Catalyzed Cascade C-H Activation/Annulation of Cyclic 2-Diazo-1,3-diketones with Benzoylacetonitriles to Polycyclic Benzo[de]chromenes

Abstract

The Rh(III)-catalyzed cascade C-H activation/benzannulation reactions of cyclic 2-diazo-1,3-diketones with benzoylacetonitriles leading to a simple and efficient strategy for the synthesis of polycyclic benzo[de]chromenes in good-tohigh yields has been described. Four new bonds and two rings are generated through sequential C-H activation, carbenoid insertion, migratory insertion, and intramolecular annulation process in a single procedure. This protocol is features with readily available starting materials, favorable functional group compatibility, and high efficiency, atom-and step-economy.