Condition optimization for photocatalytic defluoroalkylation of polyfluoroarenes.
| ||
|---|---|---|
| Entry | Deviation | Yieldb (%) |
| 1a | No | 87c |
| 2 | Ir(ppy)3 (2 mol%) instead of 4-CzIPN | 0 |
| 3 | PC1 (1 mol%) instead of 4-CzIPN | 6 |
| 4 | PC2 (1 mol%) instead of 4-CzIPN | 70 |
| 5 | MeCN, EtOAc, DMF, or DMA as solvent | <15 |
| 6 | No light, 4-CzIPN, or quinuclidine | 0 |
| 7 | Without ZnCl2 | 28 |
| 8 | Without K3PO4 | 86 |
| 9 | ZnCl2 (50 mol%) and without K3PO4 | 70 |
a
Reaction conditions: methyl 2,3,4,5,6-pentafluorobenzoate (1a, 0.20 mmol), hexan-1-ol (2a, 0.30 mmol), 4-CzIPN (3 mol%), quinuclidine (30 mol%), ZnCl2 (0.30 mmol), DMSO (4 mL), 18 W blue LED irradiation, room temperature, 24 h.
b
Yields of 3aa were determined by analysis of the crude 1H NMR spectra using 1,3,5-trimethoxybenzene as an internal standard.
c
Isolated yields.