Table 1. Optimization of Reaction Conditionsa.
| entry | catalyst (mol %) | additive (equiv) | temp (°C) | time (h) | yieldb (%) |
|---|---|---|---|---|---|
| 1 | PEG-400 (5) | 110 | 10 | NR | |
| 2c | PEG-400 (5) | 110 | 10 | NR | |
| 3 | CuI (20) | PEG-400 (5) | 110 | 10 | traces |
| 4 | ZnI2 (20) | PEG-400 (5) | 110 | 10 | NR |
| 5 | KI (20) | PEG-400 (5) | 110 | 10 | 10 |
| 6 | KIO3 (20) | PEG-400 (5) | 110 | 10 | 61 |
| 7 | NaIO3 (20) | PEG-400 (5) | 110 | 10 | 35 |
| 8 | I2 (20) | PEG-400 (5) | 110 | 10 | 38 |
| 9 | KIO3 (20) | Et. lactate (5) | 110 | 10 | 67 |
| 10 | KIO3 (20) | glycerol (5) | 110 | 10 | 86 |
| 11 | KIO3 (20) | DMSO (5) | 110 | 10 | 52 |
| 12 | KIO3 (20) | toluene (5) | 110 | 10 | traces |
| 13 | KIO3 (15) | glycerol (5) | 110 | 10 | 85 |
| 14 | KIO3 (10) | glycerol (5) | 110 | 10 | 65 |
| 15 | KIO3 (15) | glycerol (5) | 100 | 10 | 86 |
| 16 | KIO3 (15) | glycerol (5) | 90 | 10 | 72 |
| 17 | KIO3 (15) | glycerol (5) | 100 | 8 | 86 |
| 18 | KIO3 (15) | glycerol (5) | 100 | 6 | 70 |
| 19 | KIO3 (15) | glycerol (3) | 100 | 10 | 71 |
| 20d | KIO3 (15) | glycerol | 100 | 10 | 85 |
a
Reaction conditions: 1a (0.25 mmol), 2a (0.125 mmol), catalyst (mol %), and additive (equivalent).
b
Isolated yields.
c
Reaction under argon atmosphere.
d
2 mL glycerol.