Au-Catalyzed Synthesis of Thiopyrano[2,3-b]indoles Featuring Tandem Rearrangement and Hydroarylation

Abstract

Gold(III)-catalyzed synthesis of 14-π electron heteroaromatic thiopyrano[2,3-b]indole is reported using conjugated enyne tethered indole sulfides, featuring skeletal rearrangement conjoined with intramolecular hydroarylation (via C3–H functionalization of the indole core) and oxidative aromatization. Subsequent Pd-catalyzed C–C coupling resulted in a 16-π electron heteroaromatic isothiochromeno[1,8,7-bcd]indole.