Table 1. Homogeneous catalysisa.
| Entry | Catalyst, mol% | Reusability | Medium | T, °C | Time | Yield, % | Ref. |
|---|---|---|---|---|---|---|---|
| 1 | Molecular iodine (5) | NO | S-F or C2H5Cl2 | 125 or r.t | 4–9 h or 10–26 h | 20–90 or 35–93 | 97 |
| 2 | Sulfamic acid (2.5 mmol) | NO | US | 30 | 15–120 min | 55–94 | 98 |
| 3 | Triethylammonium acetate (20) | NO | S-F | 90 | 40–90 min | 60–91 | 64 |
| 4 | Molybdophosphoric acid (0.12 g) | NO | Ethyl acetate | 65 | 3–4 h | 86–97 | 99 |
| 5 | p-Toluenesulfonic (10) | NO | CH2Cl2 | r.t | 8–24 h | 58–93 | 100 |
| 6 | Adipic acid (10) | NO | S-F | 120 | 9–76 min | 83–96 | 101 |
| 7 | p-Toluenesulfonic (30) | NO | S-F | 115 | 4.5–5.5 h | 80–90 | 102 |
| 8 | Phenylboronic acid (15) | NO | S-F | 120 | 1–7 h | 58–91 | 69 |
| 9 | PTSA (15) | NO | S-F | 80 | 24–60 min | 68–88 | 37 |
| 10 | Ascorbic acid (8.5) | NO | S-F | 100 | 4–12 min | 75–96 | 103 |
a
S-F: Solvent free, US: ultrasound irradiation.