Table 1. Optimization of Reaction Conditionsa.
| entry | SiR3 | additive | cat. (mol %) | light source | solvent | yieldb (%) |
|---|---|---|---|---|---|---|
| 1 | TMS | DIPEA | 1% | 10 W blue LED | THF | 0 |
| 2 | TMS | 1% | 10 W blue LED | THF | trace | |
| 3 | TES | 1% | 10 W blue LED | THF | 13% | |
| 4 | TIPS | 1% | 10 W blue LED | THF | 25% | |
| 5 | TIPS | 1% | 10 W blue LED | dioxane | trace | |
| 6 | TIPS | 1% | 10 W blue LED | DMF | 5% | |
| 7 | TIPS | 1% | 10 W blue LED | DMSO | 5% | |
| 8 | TIPS | 1% | 10 W blue LED | hexane | N.D. | |
| 9 | TIPS | 1% | 10 W blue LED | CH3CN | 50 | |
| 10 | TIPS | 1% | 5 W blue LED | CH3CN | 37 | |
| 11 | TIPS | 1% | 15 W blue LED | CH3CN | 50 | |
| 12 | TIPS | 1% | 10 W white LED | CH3CN | 25 | |
| 13c | TIPS | 1% | 10 W blue LED | CH3CN | 69 | |
| 14c | TIPS | 2% | 10 W blue LED | CH3CN | 64 | |
| 15c | TIPS | 3% | 10 W blue LED | CH3CN | 60 | |
| 16c,d | TIPS | 1% | 10 W blue LED | CH3CN | 80 | |
| 17c,e | TIPS | 1% | 10 W blue LED | CH3CN | 85 | |
| 18c,e | TIPS | 10 W blue LED | CH3CN | N.D. | ||
| 19c,e | TIPS | 1% | CH3CN | N.D. |
Reaction conditions: 1a (0.5 mmol, 1.0 equiv), CF3Br (1.0 atm), photocatalyst (0.005 mmol, 1 mol %) in a 20 mL quartz tube, room temperature, 10 W blue LED.
Isolated yield.
Replace the air in the container with CF3Br three times and then fill it with CF3Br (1.5 atm).
25 mL flask.
50 mL Schlenk flask. N.D.: not detected.