Design and Atroposelective Construction of IAN analogues by Organocatalytic Asymmetric Heteroannulation of Alkynes

Abstract

An organocatalytic atroposelective strategy for accessing enantioenriched axially chiral IAN analogues was developed for the first time. A class of novel atropisomeric C2-arylquinoline skeletons were synthesized with high enantiocontrol via chiral phosphoric-acid-catalyzed heteroannulation of in situ generated vinylidene ortho-quinone methide (VQM) intermediates with ortho-aminophenones. The strategy tolerated a broad substrate scope, providing a facile organocatalytic approach to IAN analogues in good yields and excellent enantioselectivities under mild reaction conditions. Moreover, the synthetic utility of this methodology was illustrated through further transformations into IAN-type ligand and axially chiral thiourea.