Table 4 Comparison of the efficiency of NH4VO3 with other catalysts for synthesizing 1,4-DHP (1f.).
Entry | Catalyst (amount of catalyst) | Condition | Time (min) | Yielda (%) | References |
|---|---|---|---|---|---|
1 | Nano-ZnO (10Â mol%) | EtOH/r. t | 50 | 83 | |
2 | Nano-g-Alumina (10Â mg) | EtOH/r. t | 50 | 85 | |
3 | Nano-ZMS-5 (10Â mg) | EtOH/r. t | 55 | 90 | |
4 | Succinic acid (0.5 mmol) | EtOH: H2O/80 (°C) | 150 | 92 | |
5 | PhB(OH)2 (10Â mol%) | EtOH/reflux | 5Â h | 82 | |
6 | PPh3 (20Â mol%) | EtOH/reflux | 120 | 81 | |
7 | NH4VO3(15Â mg) | EtOH/reflux | 20 | 93 | This work |
