Formal [4+3] Epoxide Cascade Reaction via a Complementary Ambiphilic Pairing Strategy

A formal [4+3] epoxide cascade protocol utilizing ambiphilic sulfonamides and a variety of epoxides (masked ambiphiles) has been developed for the generation of benzothiaoxazepine-1,1′-dioxides and oxathiazepine-1,1′-dioxides. This protocol combines an epoxide ring-opening with either an S_NAr or oxa-Michael cyclization pathway.