Table 1.
Optimization of reaction conditions for the formation of the sulfinate 2 a from 4-iodotoluene.[a]
| Entry | Ligand | Reductant | Yield [%][b] |
|---|---|---|---|
| 1 | PtBu3⋅HBF4 | HCO2Na | 68 |
| 2 | PtBu3⋅HBF4 | HCO2K | 38 |
| 3 | PtBu3⋅HBF4 | (HCO2)2Ca | 71 |
| 4 | binap | (HCO2)2Ca | 23 |
| 5 | dppf | (HCO2)2Ca | 84 |
| 6 | dccp⋅(HBF4)2 | (HCO2)2Ca | 25 |
| 7 | PCy3⋅HBF4 | (HCO2)2Ca | 88 |
| 8 | PtBu2Me⋅HBF4 | (HCO2)2Ca | 95 |
| 9 | PAd2Bu | (HCO2)2Ca | 96 |
| 10 | PAd2Bu | none | 96 |
| 11[c] | PAd2Bu | none | 99 |
| 12[d] | PAd2Bu | none | 91 |
[a]
Reaction conditions: Pd(OAc)2 (10 mol %), ligand (20 mol %), DABSO (1.1 equiv), Et3N (3.0 equiv), iPrOH [0.2 m], 75 °C, 16 h.
[b]
HPLC yield relative to an internal standard.
[c]
Pd(OAc)2 (5 mol %), PAd2Bu (7.5 mol %), DABSO (0.6 equiv).
[d]
Pd(OAc)2 (0.5 mol %), PAd2Bu (0.75 mol %). binap=2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyl, dccp=1,3-bis(dicyclohexylphosphino)propane, dppf=1,1′-bis(diphenylphosphino)ferrocene.