Table 1.
Entry | Ligand | Base | Solvent | Yield (%) |
---|---|---|---|---|
1b | L1 | K2HPO4 | DMA | 37 |
2 | L1 | K2HPO4 | DMA | 0 |
3 | L2 | K2HPO4 | DMA | 0 |
4 | L3 | K2HPO4 | DMA | 0 |
5 | L4 | K2HPO4 | DMA | 65 |
6 | L5 | K2HPO4 | DMA | trace |
7 | L6 | K2HPO4 | DMA | trace |
8c | L7 | K2HPO4 | DMA | <5 |
9c | L8 | K2HPO4 | DMA | 0 |
10 | No L | K2HPO4 | DMA | 0 |
11 | L4 | KHCO3 | DMA | 80 |
12 | L4 | K2HPO4 | CH3CN | 86 |
Conditions: 4-Trifluoro-phenylacetic acid (1.0 mmol), Pd(OAc)2 (2 mol%), ligand (4 mol%), H2O2 (35% aqueous solution, 3.5 equiv.), base (1.5 equiv.) in solvent (3.0 mL) r.t., 24 h. Yields were determined by 1H NMR using CH3NO2 as the internal standard.
90°C.
2 mol% ligand.