Selective Access to Sultams and Spirocyclic Sultams by the Divergent Annulations of (N‐Aryl)‐Alkynyl Sulphonamides

Abstract

Herein, we present the first annulation reaction of (N‐aryl)‐alkynyl sulphonamides leading to sultams or spirocyclic sultams. The selective formation of aforesaid products is based on the variable reactivity, intramolecular ortho‐cyclization or dearomative ipso‐annulation, guided by the substituent on N‐aryl group of the substrate. The ortho‐annulation is mediated by electrophile, while the ipso‐annulation is promoted by the radical, enabling the functionalization (selenyl or iodo) on sultams. The synthetic potential of this method is illustrated by modifications of the functional groups present in the products obtained.