A mild and efficient organocatalyzed [3+2] cycloaddition of isatin-derived ketimines and 2-ylideneindane-1,3-diones has been realized. The resulting spiro[oxindole-3,2′-pyrrolidine]s bearing both a spiro indane-1,3-dione motif and a trifluoromethyl group were obtained in high yields with good diastereo- and enantioselectivities.
Key words
asymmetric synthesis - indane-1,3-dione - isatin-based ketimine - organocatalysis - spiro[oxindole-3,2′-pyrrolidine]