Table 2.
Optimization of reaction conditions a.
| Entry | Additive (equiv.) | MW (W) | T (°C) | Time (min) | Yield (%) b |
|---|---|---|---|---|---|
| 1 | DMSO (3.0) | 100 | 100 | 15 | 90 |
| 2 | CH3CN (3.0) | 100 | 100 | 15 | 35 |
| 3 | EtOH (3.0) | 100 | 100 | 15 | 25 |
| 4 | Dioxane (3.0) | 100 | 100 | 15 | 40 |
| 5 | H2O (3.0) | 100 | 100 | 15 | - |
| 6 | TBHP (3.0) | 100 | 100 | 15 | - |
| 7 | - | 100 | 100 | 15 | 10 |
| 8 c | DMSO (3.0) | 100 | 100 | 15 | 29 |
| 9 | DMSO (2.0) | 100 | 100 | 15 | 78 |
| 10 | DMSO (4.0) | 100 | 100 | 15 | 90 |
| 11 | DMSO (3.0) | 100 | 100 | 10 | 73 |
| 12 | DMSO (3.0) | 100 | 100 | 20 | 88 |
| 13 | DMSO (3.0) | 100 | 80 | 15 | 68 |
| 14 | DMSO (3.0) | 100 | 120 | 15 | 77 |
| 15 | DMSO (3.0) | 120 | 100 | 15 | 86 |
| 16 | DMSO (3.0) | 80 | 100 | 15 | 70 |
| 17 d | DMSO (3.0) | - | 100 | 24 h | 57 |
a Reaction conditions: 1a (0.25 mmol), 2a (2.0 equiv.), CuI (3.0 mol %), DMSO (3.0 equiv.) under MW irradiation; b Isolated yield; c Reaction under argon atmosphere; d Conventional heating.