Metal-free oxidative C-C bond formation of active methylenic sp C-H bonds with benzylic sp C-H and allylic sp C-H bonds mediated by DDQ

An efficient and simple method for the oxidative coupling of benzylic and allylic sp³ C-H bonds with active methylenic sp³ C-H bonds under metal-free conditions was developed by employing 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) as an oxidant. The reaction was shown to proceed smoothly for various 1,3-dicarbonyl compounds with a range of benzylic and allylic substrates in good to excellent yields.