Optimization of the reaction conditionsa.
| ||||
|---|---|---|---|---|
| Entry | R | Cat. (mol%) | 2 (eq.) | Yieldb |
| 1 | –OCH3 (1a) | Rh2(OPiv)4 (5) | 5.0 | 73% |
| 2 | –OCH3 (1a) | PtCl2 (5) | 5.0 | N.D. |
| 3 | –OCH3 (1a) | PPh3AuCl/AgOTf (5) | 5.0 | N.D. |
| 4c | –OCH3 (1a) | Rh2(OPiv)4 (5) | 5.0 | Trace |
| 5 | –OBn (1b) | Rh2(OPiv)4 (5) | 5.0 | 82% |
| 6 | –tBu (1c) | Rh2(OPiv)4 (5) | 5.0 | 80% |
| 7 | –Ph (1d) | Rh2(OPiv)4 (5) | 5.0 | 74% |
| 8 | –CH3 (1e) | Rh2(OPiv)4 (5) | 5.0 | 94% |
| 9 | –CH3 (1e) | Rh2(OPiv)4 (1) | 5.0 | 84% |
| 10d | –CH3 (1e) | Rh2(OPiv)4 (1) | 5.0 | 97% |
| 11d | –CH3 (1e) | Rh2(OPiv)4 (1) | 2.0 | 95%(82%)e |
a
Reaction conditions: 1 (0.2 mmol), 2a and the catalyst in 2 mL of DCE at 80 °C for 24 h.
b
NMR yield.
c
60 °C.
d
48 h.
e
Isolated yield. DCE: 1,2-dichloroethane.