Table 1.
Optimization of the Reaction and Its Conditionsa
| |||
|---|---|---|---|
| entry | base (equiv) | solvent (mL) | yield (%)b |
| 1 | LiOtBu (1.0) | PhCF3 (1.0) | 42 |
| 2 | LiOtBu (1.0) | PhCl (1.0) | 67 (65)c |
| 3 | LiOtBu (1.0) | CH3CN (1.0) | 10 |
| 4 | LiOtBu (1.0) | PhH (1.0) | 49 |
| 5 | NaOtBu (1.0) | PhCl (1.0) | 24 |
| 6 | KOtBu (1.0) | PhCl (1.0) | 2 |
| 7 | – | PhCl (1.0) | – |
| 8 | LiOtBu (0.75) | PhCl (1.0) | 45 |
| 9 | LiOtBu (1.25) | PhCl (1.0) | 63 |
| 10 | LiOtBu (1.5) | PhCl (1.0) | 35 |
| 11d | LiOtBu (1.0) | PhCl (1.0) | 7 |
| 12e | LiOtBu (1.0) | PhCl (1.0) | 44 |
| 13f | LiOtBu (1.0) | PhCl (1.0) | 60 |
| 14g | LiOtBu (1.0) | PhCl (1.0) | 16 |
a
Reaction conditions: 1a (0.2 mmol, 1 equiv), 2a (1.0 mmol, 5 equiv), base (1 equiv), solvent (1 mL), room temperature around the reaction flask of 35 °C (heating caused by the LED lamp), reaction flask capped, overnight.
b
1H NMR yields using dibromomethane as the internal standard.
c
Isolated yield.
d
Reaction performed at 60 °C without light.
e
With 2.5 equiv of 2a instead of 5 equiv.
f
With 4 equiv of 2a intead of 5 equiv.
g
Reaction performed by adding 20 μL of H2O.