Transition Metal-Free α-Csp3-H Methylenation of Ketones to Form C=C Bond Using Dimethyl Sulfoxide as Carbon Source

A direct alpha-Csp(3)-H methylenation of arylke-tones to form C=C bond using dimethyl sulfoxide as one carbon source is achieved under transition metal-free reaction condition. Various aryl ketone derivatives react readily with DMSO, producing the alpha,beta-unsatirated carbonyl compounds in yields of 42 to 90%. This method features a transition metal free reaction condition, wide substrate scope and using DMSO as novel one-carbon source to form C=C bond, thus providing an efficient and expeditious approach to an important class of alpha,beta-unsaturated carbonyl compounds. Based on the preliminary experiments, a plausible mechanism of this transformation is disclosed.