Entry | Catalyst | Solvent | Temp (oC) | Yield (%)b |
1 | 5a | CH2Cl2 | rt | 74 |
2 | 5b | CH2Cl2 | rt | 63 |
3 | 4a | CH2Cl2 | rt | 67 |
4 | 4b | CH2Cl2 | rt | 61 |
5 | 5a | Toluene | rt | 34 |
6 | 5a | CHCl3 | rt | 81 |
7 | 5a | ClCH2CH2Cl | rt | 54 |
8 | 5a | CHCl3 | 0 | 69 |
9 | 5a | CHCl3 | 40 | 91 |