Copper-catalyzed carbene/alkyne metathesis terminated with the Buchner reaction: synthesis of dihydrocyclohepta[b]indoles.

A copper-catalyzed selective cascade reaction of alkyne-tethered diazo compounds is reported for the direct and efficient construction of dihydrocyclohepta[b]indole skeletons under mild reaction conditions. A vinyl copper carbene is the key intermediate, which is generated in situ via carbene/alkyne metathesis (CAM) and terminated with the Buchner reaction.