Table 1. Optimization of Reaction Conditionsa.
entry | Pd(OAc)2 (mol %) | base | solvent | temp (°C), time | yieldb (%) |
---|---|---|---|---|---|
1 | 10 | KOAc | DMF | 100, 30 min | 19 |
2 | 10 | KOAc | DMF | 120, 30 min | 36 |
3 | 10 | KOAc | DMF | 140, 30 min | 42 |
4 | 10 | KOAc | DMF | 160, 30 min | 66 |
5 | 10 | KOAc | DMF | 170, 30 min | 51 |
6 | 10 | KOAc | DMF | 180, 30 min | 49 |
7 | 10 | KOAc | DMF | 160, 1 h | 84 |
8 | 2 | KOAc | DMF | 160, 1 h | 45 |
9 | 4 | KOAc | DMF | 160, 1 h | 56 |
10 | 6 | KOAc | DMF | 160, 1 h | 68 |
11 | 8 | KOAc | DMF | 160, 1 h | 78 |
12 | 10 | CsOAc | DMF | 160, 1 h | 67 |
13 | 10 | NaOAc | DMF | 160, 1 h | 54 |
14 | 10 | K2CO3 | DMF | 160, 1 h | 35 |
15 | 10 | Cs2CO3 | DMF | 160, 1 h | 23 |
16 | 10 | KOAc | DMAc | 160, 1 h | 77 |
17 | 10 | KOAc | NMP | 160, 1 h | 62 |
18 | 10 | KOAc | xylene | 160, 1 h | 35 |
19 | 10 | KOAc | dioxane | 160, 1 h | 24 |
20 | 10 | KOAc | butan-1-ol | 160, 1 h | 11 |
Reaction conditions: 1a (1 mmol), 2a (1 mmol), 3a (2 mmol), base (2 mmol), solvent (6 mL).
Isolated yield.