| Entry | Catalyst (mol%) | Time (h) | Yield (%)b |
| 1 | 5 | 5 | 45 |
| 2 | 10 | 5 | 61 |
| 3 | 15 | 5 | 67 |
| 4 | 20 | 5 | 89 |
| 5 | 25 | 5 | 87 |
| 6 | 30 | 5 | 84 |
| 7 | 20 | 2 | 52 |
| 8 | 20 | 4 | 73 |
| 9 | 20 | 6 | 85 |
| 10 | 20 | 8 | 88 |