Benzyne Polyfunctionalization via a Tandem C-C σ-Bond Insertion and Photo-Nazarov Cyclization.

A tandem benzyne C-C σ-bond insertion reaction and photo-Nazarov cyclization protocol was developed, leading to the formation of three C-C bonds at consecutive positions of a benzene ring with concomitant assembly of a 6-5-6 tricyclic ring system. When 3-silylbenzyne precursors were employed, a tandem process involving a benzyne C-C σ-bond insertion, a photo-Nazarov cyclization, and a 1,3-silyl group migration was observed, which could produce 1,2,3,5-tetrasubstituted benzenes.