A Formal Intermolecular [4+1] Cycloaddition Reaction Of 3-Chlorooxindole And O-Quinone Methides: A Facile Synthesis Of Spirocyclic Oxindole Scaffolds

Herein, we developed an efficient and straightforward method for the rapid synthesis of spirocyclic oxindole scaffolds via the [4 + 1] cyclization reaction of 3-chlorooxindole with o-quinone methides (o-QMs), which were generated under mild conditions. The products could be obtained in excellent yields with numerous types of 3-chlorooxindole. This methodology features mild reaction conditions, high atom-economy and broad substrate scope.