Table 1.
| ||||||
---|---|---|---|---|---|---|
Entry | Ni (mol%) | Ligand (mol%) | Temp (°C) | Solvent | Conv.(%) | Yield (%)[a] |
1 | 10% | dppp (12) | 100 | Tol | 100 | 0 |
2 | 10% | dppb (12) | 100 | Tol | 100 | 0 |
3 | 10% | dppe (12) | 100 | Tol | 100 | 0 |
4 | 10% | BINAP (12) | 100 | Tol | 100 | 0 |
5 | 10% | PPh3 (24) | 100 | Tol | 100 | 92 |
6 | 10% | PCy3 (24) | 100 | Tol | 100 | 80 |
7 | 10% | PPh3 (12) | 100 | Tol | 100 | 92 |
8 | 10% | PPh3 (12) | 100 | THF | 100 | 85 |
9 | 10% | PPh3 (12) | 100 | 1,4-dioxane | 100 | 86 |
10 | 5% | PPh3 (6) | 100 | Tol | 100 | 91 |
11 | 2.5% | PPh3 (3) | 100 | Tol | 75 | 71 |
12[b] | 10% | PPh3 (12) | 25 | Tol | 100 | 91 |
Determined by 1H NMR using mesitylene as the internal standard. PCy3 = tricyclohexylphosphine. cod = 1,5-cyclooctadiene.
72 h.