Unexpected formation of [5]helicenes from hexaarylbenzenes containing pyrrole moieties

Abstract

A synthetic route to hexaarylbenzenes containing up to six pyrrole units was developed. These pyrrole moieties are connected to the central benzene core via their β-carbon atom. Oxidative cyclodehydrogenation of systems containing one pyrrole ring led to the formation of [5]helicenes instead of the completely fused coronene-like structure.