NHC-catalyzed regiodivergent transformations of Ynones with trifluoromethyl ketones: Aldol reaction or [3+2] annulation

A novel NHC-catalyzed regiodivergent reaction of ynones with trifluoromethyl ketones consisting of Aldol reactions and intermolecular [3 + 2] annulations has been developed. Employing two different NHC catalysts, various tertiary alcohols and dihyrofuranones containing trifluoromethyl can be obtained in moderate to good yields (35 examples, up to 91% yield). This protocol features mild reaction conditions, high efficiency and broad substrates scope, promoting the development of NHC catalysis and transformations of ynones.