Synthesis of Spirooxindoles from N-Arylamide Derivatives via Oxidative C(sp2)–C(sp3) Bond Formation Mediated by PhI(OMe)2 Generated in Situ

A class of novel spirooxindole compounds ( 2 ) were readily synthesized, in a metal-free environment, from N -arylamide derivatives ( 1 ) via intramolecular oxidative cyclization. Direct oxidative C(sp 2 )–C(sp 3 ) bond formation was realized with the least-studied PhI(OMe) 2 as an oxidant, formed in situ from the reaction between PhIO and MeOH.