Background: A cheap and commercially available organocatalyst, 4-dimethylaminopyridine
was successfully employed in the regioselective [3+2] cycloaddition of isatin-derived Morita-Baylis-
Hillman carbonates with azonaphthalenes for the construction of 3-spiropyrazole-2-oxindoles in excellent
yields under mild conditions.
Methods: In the presence of 4-dimethylaminopyridine with a loading of 10 mol%, a series of isatinderived
Morita-Baylis-Hillman carbonates reacted smoothly with azonaphthalenes in dichloromethane
at room temperature to furnish 3-spiropyrazole-2-oxindoles in 72-98% yield.
Results and Conclusion: In summary, we have developed reasonably cheap and commercially available
4-dimethylaminopyridine-mediated regioselective [3+2] annulations between isatin-derived Morita-
Baylis-Hillman carbonates and azonaphthalenes for the construction of 3-spiropyrazole-2-oxindoles
under mild conditions.