Pd-Catalyzed asymmetric decarboxylative cycloaddition of vinylethylene carbonates with 3-cyanochromones

Abstract

An efficient method for the construction of furanobenzodihydropyran skeletons has been developed through Pd-catalyzed asymmetric decarboxylative cycloaddition of vinylethylene carbonates with 3-cyanochromones. By using a palladium complex generated in situ from [Pd₂(dba)₃]·CHCl₃ and phosphoramidite L3 as a catalyst under mild reaction conditions, the process afforded furanobenzodihydropyrans bearing vicinal quaternary stereocenters in high yields with good to high enantio- and diastereoselectivities.