Cobalt-Catalyzed Intramolecular Dearomative Alkylation of Phenols with Alkenes

A cobalt-catalyzed intramolecular dearomative <i>ipso</i>-spirocyclization of phenols bearing a tethered alkene has been developed. A range of structurally unique spirocyclodienone lactams were achieved in moderate to excellent yields. Synthetic transformations of the product were carried out to demonstrate the practical utility of the reaction. The primary result about the asymmetric reaction was also presented.