Table 4. Effect of Different Catalysts on HMF Conversion and DFF Yield in CH3CNa.
| entry | catalyst, loading (mol %) | cocatalyst | additive | time (h) | conv. HMF (%) | yield DFF (%) | select.b (%) |
|---|---|---|---|---|---|---|---|
| 1 | Fe(NO3)3·9H2O, 5 | TEMPO | 24 | 96 | 91 | 95 | |
| 2 | Fe(NO3)3·9H2O, 5 | TEMPO | NaNO2 | 10 | 100 | 94 | 94 |
| 3 | Fe(NO3)3·9H2O, 5 | TEMPO | NaCl | 15 | 99 | 98 | 98 |
| 4 | Fe(NO3)3·9H2O, 5 | TEMPO | C4H9NO2 | 24 | 58 | 58 | 100 |
| 5 | TEMPO | NaNO2 | 24 | NR | |||
| 6 | Fe(NO3)3·9H2O, 5 | NaNO2 | 24 | NR | |||
| 7 | Fe(acac)3, 5 | TEMPO | NaNO2 | 24 | 2 | 0 | 0 |
| 8 | FeCl3·6H2O, 5 | TEMPO | NaNO2 | 24 | 36 | 36 | 100 |
| 9 | Cu(NO3)2·3H2O, 5 | TEMPO | NaNO2 | 10 | 62 | 61 | 98 |
| 10 | Cu(NO3)2·3H2O, 7.5 | TEMPO | NaNO2 | 10 | 100 | 99 | 99 |
| 11 | Al(NO3)3·9H2O, 5 | TEMPO | NaNO2 | 10 | 77 | 77 | 100 |
| 12 | Zn(NO3)2·6H2O, 5 | TEMPO | NaNO2 | 10 | 61 | 60 | 98 |
| 13 | Zn(NO3)2·6H2O, 7.5 | TEMPO | NaNO2 | 10 | 68 | 65 | 96 |
| 14 | NaNO3, 5 | TEMPO | NaNO2 | 10 | 5 | 1 | 20 |
| 15 | KNO3, 5 | TEMPO | NaNO2 | 10 | 2 | 1 | 50 |
a
Reaction conditions: HMF (1 mmol, 126 mg), additive (0.05 mmol), CH3CN (5 mL), 50 °C, and oxygen balloon. NR = no reaction. The conversion and yield were determined by HPLC. Conv. = conversion. Select. = selectivity.
b
S (DFF) = yield (DFF)/conversion (HMF).