Radical Functionalization of 1,6-Diene via Transannular Cyano Migration: Synthesis of Polysubstituted Cyclopentanes†

Abstract

An efficient transannular cyano migration is reported for gem-dicyano-1,6-diene, which is triggered by the addition of external arylsulfonyl radicals. The overall transformation proceeds through a sequence of intramolecular 5-exo-trig cyclization, suprafacial 1,4-cyano migration, and the capture by H or D atom, leading to the production of valuable polysubstituted cyclopentanes under mild photoredox catalytic conditions. The reaction is adapted to a wide range of sodium (hetero)arylsulfinates, demonstrating good functional group compatibility. This method provides a new protocol for radical-mediated functional group migration.