Expedient synthesis of 9,10-phenanthrenes via LiOPiv-promoted and palladium-catalysed aryne annulation by vinyl triflates

Abstract

A novel LiOPiv-promoted and palladium-catalysed formal [2 + 2 + 2] annulation reaction of vinyl triflates and o-silylaryl triflates via aryne intermediates has been developed. This methodology affords good to excellent yields of 9,10-substituted phenanthrenes (including cyclohexa[l]phenanthrenes) and is tolerant of a variety of functional groups such as ester, cyano, and ketone.