Table 1.
Optimization of the reaction conditions.[a]
|
| |||
|---|---|---|---|
|
Entry[a] |
Catalysts |
Time |
Yield [%][d] |
|
1 |
(IPr)Au(NCMe)SbF6 |
1 h |
94 |
|
2 |
Ph3PAuNTf2 |
1 h |
94 |
|
3[b] |
(CF3CH2O)3PAuCl/NTf2 |
2.5 h |
90[e] |
|
4 |
(SPhos)AuCl/AgNTf2 |
1 h |
88 |
|
5[c] |
(IPr)Au(NCMe)SbF6 |
15 min |
96 |
|
6 |
(IPr)AuCl |
4 h |
10 (89)[f] |
|
7 |
(IPr*)AuCl/AgSbF6 |
1 h |
90[e] |
|
8 |
AgNTf2 |
5 h |
48 (36)[f] |
[a] Reactions were run on 0.01 mmol scale in CDCl3, and were afterwards directly analyzed by 1H NMR spectroscopy. [b] 60 °C. [c] In [D6]benzene. [d] Yield was determined by 1H NMR by using hexamethylbenzene as the internal standard. [e] Isolated yield. [f] Recovery of 1 a. 