Yuyu Cheng, Zhongyue Lu and Pengfei Li* Pages 134 - 139 ( 6 )
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.
Annulation, azonaphthalenes, MBH carbonates, 4-dimethylaminopyridine, regioselective, spirooxindole.
Department of Chemistry, Southern University of Science and Technology, Department of Chemistry, Southern University of Science and Technology, Department of Chemistry, Southern University of Science and Technology