Metal‐Free Direct C–H β‐Carbonyl Alkylation of Heteroarenes with Cyclopropanols Mediated by K2S2O8

Direct C–H β‐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 β‐carbonyl alkylation efficiently via K2S2O8‐mediated ring‐opening of cyclopropanols. The corresponding β‐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. A metal‐free direct C–H β‐carbonyl alkylation of heteroarenes has been achieved through K2S2O8‐mediated ring‐opening of cyclopropanols. A wide scope of substrates, such as various substituted quinolines and isoquinolines, pyridines, pyridazine, benzo[d]thiazole, and phenanthroline, underwent the β‐carbonyl alkylation efficiently and afforded the β‐heteroarylated ketones in moderate to excellent yields.