Rh(II)/Chiral Phosphoric Acid-Cocatalyzed Enantioselective Synthesis of Spirooxindole-Fused Thiaindans

An asymmetric strategy for the construction of chiral sulfur-containing spirooxindole-fused heterocycles was achieved via a rhodium(II)/chiral phosphoric acid-cocatalyzed reaction between 2-mercaptophenyl ketones and 3-diazooxindoles. With this method, a series of spirooxindole-thiaindan derivatives bearing two contiguous quaternary carbon stereogenic centers were obtained in high yields with high diastereoselectivities and high-to-excellent enantioselectivities.