Metal-Free Direct C-H beta-Carbonyl Alkylation of Heteroarenes with Cyclopropanols Mediated by K2S2O8

Direct C-H beta-carbonyl alkylation of heteroarenes under metal-, acid- and photo-catalyst free conditions has been achieved. A wide scope of substrates, such as various substituted quinolines and isoquinolines, pyridines, pyridazine, benzo[d]thiazole and phenanthroline, underwent the beta-carbonyl alkylation efficiently via K2S2O8-mediated ring-opening of cyclopropanols. The corresponding beta-heteroarylated ketones were obtained in moderate to excellent yields and gram-scale experiments further demonstrated the practicality of this synthetic protocol. The readily available reagents, mild and environmentally benign conditions make the method extremely attractive. The reaction mechanism is also proposed.