Lewis Acid-Catalyzed Regioselective Substitution of 2-Indolylmethanols with Pyrroles

A Lewis acid-catalyzed regioselective C2’-electrophilic substitution of 2-indolylmethanols with pyrroles was established, which afforded indole-based tetraarylmethanes in overall high yields (up to 99%) with excellent regioselectivities. Moreover, such indole-based tetraarylmethanes exhibited potent cytotoxicity against HepG2 cancer cells, which demonstrated their potential applications in medicinal chemistry. This reaction not only represents the regioselective C2’-electrophilic substitution of 2-indolylmethanols with aryl nucleophiles (Ar-Nu), but also provides a new strategy for the synthesis of biologically important tetraarylmethanes.