Abstract
1,3-Dipolar cycloadditions involving 1,4-naphthoquinone and an azomethine ylide generated from α-amino acids and isatins have been used in this reaction to afford the pyrrolidine-2-spiro-3′-oxindole 4 or 5 with moderate to excellent yields.
ACKNOWLEDGMENTS
This work was supported in part by the Natural Science Foundation of Jiangsu Province (No. BK2006048), the Nature Science Key Basic Research of Jiangsu Province for Higher Education (No. 06KJA15007), and the National Natural Science Foundation of China (Nos. 20472062 and 20672079).
Notes
a All reactions were carried out in methanol under sonic waves.
b Isolated yields.
c The reaction was carried out in methanol under reflux conditions.
a All reactions were performed in methanol under sonic waves.
b Chemical yields are given for the isolated product.