Table 1. Optimization of Reaction Conditions for RCMa.
| entry | cat. (mol %) | additive (10 mol %) | solvent | temp (°C) | timeb (h) | yieldc (%) |
|---|---|---|---|---|---|---|
| 1 | EtOAc | 70 | 24 | |||
| 2 | GB-2d (5) | EtOAc | 70 | 24 | ||
| 3 | GB-2 (5) | EtOAc | 70 | 1 + 24 | 10 | |
| 4 | GB-2 (5) | BQ | EtOAc | 70 | 1 + 2 | 40 |
| 5 | GB-2 (5) | TFBQ | EtOAc | 70 | 1 + 2 | 90 |
| 6 | GB-2(5) | TFBQ | EtOAc | 50 | 1 + 2 | 90 |
| 7e | GB-2 (5) | TFBQ | EtOAc | 50 | 1 + 2 | 10 |
| 8f | GB-2 (5) | TFBQ | EtOAc | 50 | 1 + 2 | 40 |
| 9 | GB-2 (5) | EtOAc | 50 | 1 + 24 | 15 | |
| 10 | GB-2 (5) | TFBQ | DCM | 50 | 1 + 2 | 85 |
| 11 | GB-2 (5) | TFBQ | DCM | 25 | 1 + 24 | 40 |
| 12 | GB-2 (5) | TFBQ | EtOAc | 25 | 1 + 24 | 45 |
| 13 | GB-2 (3) | TFBQ | EtOAc | 50 | 1 + 12 | 40 |
| 14 | HG-2 (5) | TFBQ | EtOAc | 50 | 1 + 2 | 60 |
| 15 | HG-2 (5) | TFBQ | DCM | 50 | 1 + 2 | 40 |
| 16 | HG-2 (5) | BQ | EtOAc | 50 | 1 + 2 | 30 |
| 17 | HG-2 (3) | TFBQ | EtOAc | 50 | 1 + 12 | 30 |
| 18 | HG-2 (5) | TFBQ | EtOAc | 70 | 1 + 2 | 75 |
a
Reaction conditions: 1a (50 mg, 1.0 equiv), GB-2 (5 mol %), TFBQ (10 mol %), EtOAc (1 mM), 50 °C, (1 + 2) h.
b
Addition of the catalyst in six equal portions in intervals of 10 min that took 1 h for complete catalyst addition.
c
Isolated yield.
d
One portion catalyst addition.
e
Olefin concentration in solvent = 10 mM.
f
Olefin concentration in solvent = 5 mM. Reactions were performed at 1 mM concentration of olefin.