An Acid-Catalyzed Addition and Dehydration Sequence for the Synthesis of Heteroarylated Steroidal Dienes

Additions of heteroarenes to hormone steroids containing an alpha,beta-unsaturated ketone are reported. Additions of a range of electron-rich heteroarene nucleophiles, including indoles, a pyrrole, and a thiophene, to a variety of commercially available steroids and subsequent dehydration formed 3-heteroarylated steroidal dienes in up to 93% yield. This atom-economical reaction sequence occurs under mild reaction conditions in the presence of catalytic bismuth triflate.