Table 1. Catalytic reactions with various gold catalysts.
| ||||||
| Entry | Catalyst [mol%] | Solvent | t [h] | Yield
b
[%] |
||
| 4a | 5a | 4a′ | ||||
| 1 | IPrAuCl/AgSbF6 (5) | DCM | 12 | 8 | 62 | 25 |
| 2 | IPrAuCl/AgSbF6 (10) | DCM | 3 | — | 85 | 12 |
| 3 | (PhO)3PAuCl/AgSbF6 (10) | DCM | 3 | — | 82 | 16 |
| 4 | Ph3PAuCl/AgSbF6 (10) | DCM | 4 | — | 55 | 36 |
| 5 | LAuCl/AgSbF6 (10) c | DCM | 3 | — | 40 | 52 |
| 6 | IPrAuCl/AgOTf (10) | DCM | 4 | — | 65 | 26 |
| 7 | IPrAuCl/AgNTf2 (10) | DCM | 4 | — | 71 | 20 |
| 8 | AgSbF6 (10) | DCM | 24 | 95 | — | — |
| 9 | IPrAuCl/AgSbF6 (10) | DCE | 5 | — | 70 | 24 |
| 10 | IPrAuCl/AgSbF6 (10) | MeCN | 12 | — | 20 | 65 |
| 11 | IPrAuCl/AgSbF6 (10) | Dioxane | 10 | — | — | 90 |
a[4a] = 0.05 M.
bProduct yields are reported after purification from a silica column.
cL = P(t-Bu)2(o-biphenyl). IPr = 1,3-bis(diisopropylphenyl)imidazole-2-ylidene, DCE = 1,2-dichloroethane.