Table 2.
Investigation of a one-pot enantioselective synthesis of 1H-pyrrol-3(2H)-one derivatives.a
| ||||
|---|---|---|---|---|
| Entry | Additive | Solvent | Yieldb | Eec |
| 1 | --- | MeCN | 32% | 30% |
| 2 | CF3COOH | MeCN | 82% | 31% |
| 3 | CF3COOH | DCM | 67% | 47% |
| 4 | CF3COOH | CHCl3 | 64% | 41% |
| 5 | CF3COOH | DCE | 72% | 44% |
| 6 | CF3COOH | Toluene | 55% | 41% |
Reaction conditions: 1) 1a (0.10 mmol), 2a (0.20 mmol), L-proline (20 mol%), solvent (0.50 mL), rt, 24 h; 2) 5a (0.11 mmol), CF3COOH (20 mol%), 65 °C, 24 h.
Yield of the isolated product after column chromatography.
The ee value was determined by HPLC using a chiral stationary phase.