Enantioselective Synthesis of Dispirooxindole Derivatives via Asymmetric Catalytic Cascade Reactions

A series of optically active 3,3′-pyrrolidinyl-dispirooxindole derivatives containing a CF3 moiety have been efficiently constructed through asymmetric catalytic cascade reactions catalyzed by cinchona-derived bifunctional squaramide catalyst, bearing four contiguous stereogenic centers, two of which are vicinal spiro-stereocenters. Additionally, a wide range of substituted products were achieved with moderate to high yields (up to 99% yield) and excellent stereoselectivities (up to >20:1 dr for all cases and up to 99% ee).