Microwave-Promoted Synthesis of 1-Tetralones via Iminyl Radical-Mediated 1,5-Hydrogen Atom Transfer

Microwave irradiation of O-phenyloximes produces 1-tetralones via N-O homolysis, 1,5-hydrogen atom transfer (HAT), and cyclization of a radical intermediate onto an aromatic ring. The HAT step is facilitated by coordination of Lewis acid InCl3·H2O to an iminyl radical. The reaction is rapid and exhibits a broad substrate scope. A larger scale transformation can be performed using conventional heating instead of microwave irradiation.