Palladium-Catalyzed Bicycloaromatization of <i>o</i>-(Alkynyl)styrenes with Alkynes: Economical Access to Chrysene Derivatives

Abstract

Herein, a palladium-catalyzed bicycloaromatization of <i>o</i>-(alkynyl)styrenes with alkynes is reported. In this protocol, the 6-<i>endo</i>-<i>dig</i> cyclization of <i>o</i>-(alkynyl)styrenes is followed by deprotonation to complete the first cycloaromatization, and then, a regioselective alkyne insertion/C-H activation occurs to achieve the second cycloaromatization, resulting in atom- and step-economical syntheses of polysubstituted chrysenes. Notably, the products can be further used to construct π-extended arenes using the Scholl reaction.