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

Abstract A strategic approach to incorporate CF 3 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 arylidene 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 (72 %–99 %) with excellent diastereoselectivity (in all cases >20 : 1 dr), offering new candidate compounds for drug screen.