TABLE 1.
Optimization table of photocatalyst for the synthesis of 4a a .
| |||||
| Entry | Photocatalyst | Light source | Solvent (3 ml) | Time (min) | Isolated yields (%) |
| 1 | — | White light (18 W) | H2O/EtOH (2:1) | 15 | 57 |
| 2 | Na2 eosin Y (0.2 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 78 |
| 3 | Na 2 eosin Y (0.5 mol%) | White light (18 W) | H 2 O/EtOH (2:1) | 5 | 93 |
| 4 | Na2 eosin Y (1 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 93 |
| 5 | Erythrosin B (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 51 |
| 6 | Phenanthrenequinone (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 53 |
| 7 | Rhodamine B (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 72 |
| 8 | Acenaphthenequinone (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 57 |
| 9 | Riboflavin (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 64 |
| 10 | 9H-xanthen-9-one (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 60 |
| 11 | Fluorescein (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 77 |
| 12 | Rose bengal (0.5 mol%) | White light (18 W) | H2O/EtOH (2:1) | 5 | 68 |
a
Reaction conditions: benzaldehyde (1 mmol), malononitrile (1 mmol), resorcinol (1 mmol) in H2O/EtOH (2:1) (3 ml), white LED (18 W), and various photocatalysts at rt. Bold values provides optimal conditions for reaction.