Table 1.
Reaction development. 
| Entry[a] | Ru dimer (mol %) | Ag source (mol %) | Cu(OAc)2·H2O (equiv) | 6 a[%] | 7 a[%] |
|---|---|---|---|---|---|
| 1 | 5 | AgBF4 (20) | 2 | 43 | 11 |
| 2 | 2.5 | AgBF4 (10) | 2 | 32 | 4 |
| 3 | 5 | AgBF4 (10) | 2 | 53 | 8 |
| 4 | 5 | AgOTf (10) | 2 | 45 | 10 |
| 5 | 5 | AgSbF6 (10) | 2 | 55 | 6 |
| 6 | 5 | AgSbF6 (10) | 1.5 | 64 | 6 |
| 7 | – | AgBF4 (10) | 1.5 | – | – |
| 8 | 5 | – | 1.5 | – | – |
| 9 | 5 | AgBF4 (10) | – | – | – |
| 10 | 5 | HBF4 (50) | 2 | 48 | 8 |
| 11 | [b] | AgSbF6 (10) | 1.5 | 56 | 8 |
[a]
Reaction conditions: 0.5 mmol of 4 a, 1 mmol of 5 a, Ru dimer, Ag source, Cu(OAc)2⋅H2O, 2 mL of DCE, T=100°C, 8 h. Yields of isolated products are given. [b] [{Rh(Cp*)Cl2}2] (5 mol % of dimer) used. DCE=1,2-dichloroethane, Cp*=pentamethylcyclopentadienyl.