Copper(I)-Catalyzed Asymmetric Intermolecular [3+2] Cycloaddition of Azomethine Ylides with Isatin-derived Trifluoromethyl Acrylates

An efficient, reliable and atom-economic strategy employing azomethine ylides and isatin-derived trifluoromethyl acrylates via intermolecular [3+2] cycloaddition for construction of valuable highly substituted pyrroledines bearing adjacent all-carbon quaternary stereocenters (one of which is a spirocyclic all-carbon quaternary stereocenter and the other is a trifluoromethylated all-carbon quaternary stereocenter) at C3 and C4 positions has been developed for the first time. The corresponding products with a broad substrate scope, good functional group tolerance and high stereoselectivity (29 examples, 60-96% yields, 80->99% ee, dr >20:1). In addition, subsequent amplification experiment and derivations further demonstrated the applicability of the synthetic methodology.