Table 2. Optimization of reaction conditions for aerobic dehydrogenation of 2-phenyl-2,3 dihydroquinazolin-4(1H)-one using CuMnFe-LDHzyme/mediator catalytic systema.
| Entry | Mediator (mol%) | Amount of CuMnFe-LDHzyme | Temperature(°C) | Solvent | Yield (%) |
|---|---|---|---|---|---|
| 1 | DDQ (5) | 140 | 60 | CH3CN | 72 |
| 2 | 4-Phenyl urazole(5) | 140 | 60 | CH3CN | 70 |
| 3 | DDQ (10) | 140 | 60 | CH 3 CN | 98 b |
| 4 | 4-Phenyl urazole(10) | 140 | 60 | CH 3 CN | 98 b |
| 5 | DDQ (10) | 110 | 60 | CH3CN | 68 |
| 6 | 4-Phenyl urazole (10) | 110 | 60 | CH3CN | 65 |
| 7 | DDQ (10) | 130 | 60 | CH3CN | 85 |
| 8 | 4-Phenyl urazole(10) | 130 | 60 | CH3CN | 80 |
| 9 | DDQ (10) | 140 | 45 | CH3CN | 70 |
| 10 | 4-Phenyl urazole(10) | 140 | 45 | CH3CN | 75 |
| 11 | DDQ (10) | 140 | 60 | CH3CN/H2O | 35 |
| 12 | 4-Phenyl urazole(10) | 140 | 60 | CH3CN/H2O | 30 |
| 13 | DDQ (10) | 140 | 60 | DMSO | 60 |
| 14 | 4-Phenyl urazole(10) | 140 | 60 | DMSO | 60 |
a
Reaction conditions unless stated otherwise: substrate (1 mmol), CuMnFe-LDHzyme (140 mg), mediator (10 mol%), solvent (3 mL) under O2 (balloon), and 18 h;
b
The bolds represent the effective reaction conditions.