DMAP‐Catalyzed Efficient Diastereo‐ and Regioselective Synthesis of Isoxazolone‐Based Bisspiroheterocyclic Oxindoles

A strategic approach to incorporate CF3 group into oxindoles, pyrrolidines, and isoxazolones to construct spiro heterocyclic skeletons with quaternary carbon stereocenters was developed. Using a DMAP catalyst under mild conditions, the controllable synthesis of spiro oxindole‐pyrrolidine‐isoxazoline derivatives was achieved via concerted 1,3‐dipolar cycloaddition reactions of akylidene isoxazolones with N‐(2,2,2‐trifluoroethyl)isatin ketimines.This method exhibits robust regioselectivity and provides a series of isoxazolone‐based bispiro heterocycles in good to high yields (82%–99%) with excellent diastereoselectivity (in all cases >20:1 dr), offering new candidate compounds for drug screen.