Sequential Gold and Organocatalyzed Bicyclization for Asymmetric Construction of Contiguous Tetrasubstituted Carbon Stereocenters

Employing a sequential gold and organocatalytic system, we have achieved a one-pot double annulation of versatile 1,3-dicarbonyl compounds bearing a 3-butynoic acid moiety. This process proceeds through a gold-catalyzed 5-endo-dig cyclization, followed by a thiourea-catalyzed intramolecular vinylogous aldol reaction. By strategically employing desymmetrization and dynamic kinetic resolution, respectively, this methodology enables the efficient and asymmetric construction of a series of spiro-butenolide architectures incorporating contiguous tetrasubstituted carbon stereocenters.