Photoinduced Synthesis of Polycyclic γ‐Sultines by a Radical‐Polar Crossover Cyclization

Abstract

AbstractDescribed herein is a visible light‐mediated radical addition/SO2 insertion/anionic cyclization of benzo‐fused homoallylic tosylates, allowing access to a diverse array of otherwise challenging‐to‐access fluoromethylated polycyclic γ‐sultines with two adjacent tetrasubstituted carbon stereocenters in 49–95% yields, which can be further readily functionalized towards bulky two adjacent tetrasubstituted carbon‐containing benzo‐fused γ‐sultone and mercaptoalkanol. Sodium fluoroalkanesulfinates were utilized as bifunctionalization reagents for both fluoromethyl groups and SO2. The cyclization proceeds through a stepwise photoinduced radical addition followed by an intramolecular 5‐exo‐tet anionic substitution cyclization after SO2 insertion.