Diastereoselective assembly of complex benzofuran-annulated spiro-tetrahydroquinoline frameworks via Povarov cyclization

Abstract

A Sc(OTf)₃/HFIP-catalyzed annulation of isatins, anilines and 3-methylbenzofurans has been developed for the diastereoselective synthesis of spiro-tetrahydroquinolines. The reaction proceeds via a regioselectively reversed Povarov reaction as established through DFT calculations. Broad substrate scope, high functional-group tolerance, and gram-scale applicability are the key highlights of this strategy.