| Entry | Phosphine/1 (mol%) | Yieldb(%) | |
| 3 | 4 | ||
| 1 | PPh3 (10) | 82 | - |
| 2 | PPh3 (30) | 87 | - |
| 3 | PPh3 (50) | 86 | - |
| 4 | PPh3 (100) | 87 | - |
| 5 | P(p-C6H4F)3 (30) | 78 | - |
| 6 | P(p-C6H4OMe)3 (30) | 88 | - |
| 7 | PMePh2 (30) | 67 | - |
| 8 | Bu3P (30) | 14 | 12 |