Table 3. Screening of Palladium Complexesa.
| yield
(%)b |
|||||
|---|---|---|---|---|---|
| entry | Pd complex | time (h) | 2a | 4 | recovered 1 |
| 1 | (MeCN)2PdCl2 | 2 | 69 (64)c | 0 | 0 |
| 2 | (Ph3P)2PdCl2 | 23.5 | 0 | 0 | 99 |
| 3 | PdCl2 | 23.5 | 30 | 0 | 51 |
| 4 | (PhCN)2PdBr2 | 1 | 70 | 0 | 0 |
| 5 | Pd(OAc)2 | 22.5 | 0 | 5 | 83 |
| 6 | Pd(OCOCF3)2 | 22.5 | 0 | 71 | 0 |
| 7 | Pd(PPh3)4 | 16 | 0 | 0 | >99 |
| 8 | Pd2(dba)3·CHCl3 | 16 | 0 | 0 | >99 |
All reactions were conducted with 0.194 mmol of 1 in DME (1.0 mL).
Determined by 1H NMR analysis using an internal standard.
Isolated yield is given in parentheses.
