Table 5.
Yields and conditions of photoinduced biflavanone formation with amines.
| Reaction Conditions | Conversion (%) | Yields (%)*4 | ||
|---|---|---|---|---|
| Molar ratios*1, Amines*2, Solvents, Irradiation Time, Irradiation Source*3 | 39 | 40 | 41 | |
| 1/2, TEA, benzene, 25 hrs, A | 75.0 | 22.0 | 22.3 | 13.0 |
| 1/4, TEA, ACN, 25 hrs, A | 78.4 | 15.9 | 26.1 | 10.2 |
| 1/1, TEA, ACN, 14 hrs, A | 88.5 | 12.2 | 9.7 | 11.6 |
| 1/2, TEA, ACN, 14 hrs, A | 78.0 | 20.9 | 30.0 | 15.8 |
| 1/4, TEA, ACN, 14 hrs, A | 85.4 | 16.7 | 14.6 | 14.4 |
| 1/10, TEA, ACN, 14 hrs, A | 82.6 | 29.7 | 13.5 | 15.8 |
| 1/2, DMAE, benzene, 12 hrs, A | 88.8 | 15.2 | 22.8 | 13.7 |
| 1/2, TEA, DCM, 16 hrs, A | 71.1 | 17.4 | 7.9 | 16.9 |
| 1/2, TEA, benzene, 25 hrs, B | 78.7 | 17.6 | 7.5 | 8.9 |
| 1/2, TEA, ACN, 14 hrs, B | 75.8 | 12.5 | 4.8 | 11.9 |
| 1/2, DMAE, benzene, 14 hrs, A | 79.1 | 9.6 | 19.3 | 11.2 |
*1 Molar ratio of substrate to amine; *2 Amine: TEA: triethylamine, DMAE: 2-(N,N-dimethylamino)ethanol. *3 Irradiation Source: A (Sankyo 254 nm Germicidal Lamp), B (Sankyo 306 nm UV-B Lamp), *4 Yield based on consumed flavone 1.