Construction of Spirocyclopropane-Linked Heterocycles Containing Both Pyrazolones and Oxindoles through Michael/Alkylation Cascade Reactions

An effective diastereoselective Michael/alkylation cascade reaction of arylidenepyrazolones with 3-chlorooxindoles catalyzed by DIPEA was developed. A variety of highly functionalized spiro-pyrazolone-cyclopropane-oxindoles were obtained in excellent yields (up to 99%) with good to excellent diastereoselectivities (up to >25:1 dr). Moreover, the squaramide-catalyzed asymmetric reactions of arylidenepyrazolones with 3-chlorooxindoles afforded the corresponding chiral spirocyclic heterocycles in excellent yields (up to 99%) with moderate diastereoselectivities (up to 87:13 dr) and moderate to high enantioselectivities (up to 74% ee).