Highly Stereoselective [3+2] Cycloadditions of Chiral Palladium-Containing N1-1,3-Dipoles: A Divergent Approach to Enantioenriched Spirooxindoles

A catalytic asymmetric [3+ 2] cycloaddition reaction of chiral palladium-containing N-1-1,3-dipoles with methyleneindolinones has been successfully developed. The reaction allows an efficient construction of 3,3'-pyrrolinyl spirooxindoles with high yields and excellent stereoselectivities (up to 93% yield, 19:1 d.r. and >99% ee). A synthetic application of this methodology is demonstrated and a stereocontrol mechanism is proposed.