Table 1. Optimization of Reaction Conditions for the Alcohol Nucleophile.
| yielda |
|||||
|---|---|---|---|---|---|
| entry | cat. | conditions | 3ba | 4ba | ratio (3ba/4ba) |
| 1 | Ph3PAuCl/AgSbF6 | CH2Cl2, rt, 4 h | 30% | 53% | 1:1.8 |
| 2 | Et3PAuCl/AgSbF6 | CH2Cl2, rt, 1.5 h | 13% | 82% | 1:6.3 |
| 3 | (p-CF3-C6H4)3PAuCl/AgSbF6 | CH2Cl2, rt, 6 h | 44% | 37% | 1.2:1 |
| 4 | (IMes)AuCl/AgSbF6 | CH2Cl2, rt, 1 h | 10% | 87% | 1:8.7 |
| 5b | (IMes)AuCl/AgSbF6 | CH2Cl2, rt, 1.5 h | 7% | 86% | 1:12 |
| 6b | (tBu)3PAuCl/AgSbF6 | CH2Cl2, rt, 2 h | 3% | 89% | 1:30 |
| 7 | Ph3PAuCl/AgSbF6 | toluene, rt, 2 h | 56% | 23% | 2.4:1 |
| 8 | Ph3PAuCl/AgSbF6 | CH2Cl2, 0 °C, 8 h | 56% | 36% | 1.6:1 |
| 9b | (p-CF3-C6H4)3PAuCl/AgSbF6 | toluene, 0 °C, 8 h | 61% | 20% | 3:1 |
a
Isolated yield after column chromatography.
b
2 equiv of alcohol was used.