Table 2.
Product Stability Experiments
| ||||
|---|---|---|---|---|
| entry | reagent | pKa (in H2O) | time [h] | yield [%]b |
| 1 | TfOH | ca. −14 | 1 | 59 |
| 2 | TfOH | ca. −14 | 3 | 20 |
| 3 | 2b | −2.6 | 12 | 73 |
| 4 | 2b | −2.6 | 36 | 72 |
| 5 | p-TsOH | −2.8 | 12 | 6 |
| 6 | MsOH | −2.6 | 12 | 9 |
| 7 | F3CCO2H | +0.3 | 12 | 0 |
Conditions: 0.1 mmol 1i, 0.1 mmol reagent, 0.5 mL DCE (0.2 M), 90 °C.
Yield determined by 1H NMR using 1,1,2,2-tetrachloroethane as the internal standard.