TABLE 6.
Cross Coupling of Cyclic Enaminone and Arylboronic Acida
| ||||
|---|---|---|---|---|
| entry | Pd(OAc)2 | Cu(OAc)2 | CuCl2 | 3a (%) |
| 1 | none | 2 equiv | 2 equiv | 0 |
| 2 | none | 2 equiv | none | 0 |
| 3 | none | none | 2 equiv | 0 |
| 4 | 10 mol% | none | none | < 5 |
| 5 | 10 mol% | 2 equiv | 2 equiv | 81 |
| 6 | 10 mol% | 2 equiv | none | 18 |
| 7 | 10 mol% | none | 2 equiv | 18 |
| 8 | 10 mol% | 4 equiv | none | 25 |
| 9 | 100 mol% | none | none | 30 |
| 10 | 100 mol% | 2 equiv | 2 equiv | 66 |
| 11 | 100 mol% | 2 equiv | none | 49 |
| 12 | 100 mol% | none | 2 equiv | 60 |
Reaction conditions: 1 (1 equiv), 2a (2 equiv), DMF (0.2 M) under N2 at 60 °C for 1 h, the yield was determined by 1H NMR analysis of the crude product using Ph3SiMe (1 equiv) as the internal standard.