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

Abstract

Herein, a palladium-catalyzed bicycloaromatization of o-(alkynyl)styrenes with alkynes is reported. In this protocol, the 6-endo-dig cyclization of o-(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 stepeconomical syntheses of polysubstituted chrysenes. Notably, the products can be further used to construct π-extended arenes using the Scholl reaction.