Iron-Catalyzed Dearomatizing Reductive Cyclization of Arenes

An efficient iron-catalyzed intramolecular dearomatizing reductive cyclization of arenes has been developed. By employing FeBr₂ as the catalyst, tripyridine as the ligand, and Mn powder as the reductant, a series of spiro-cyclohexadienes and dihydronaphthalenes were afforded in moderate to excellent yields with aryliodine-tethered benzyl tert-butyl carbonate or naphthalene derivatives as substrates. In addition, several synthetic transformations were conducted to demonstrate the utility of the reaction, and control experiments were carried out to gain insight into the mechanism.