Table 3. Self-condensation of butanol catalyzed by Ir catalysts in aqueous phasea.
| Entry | Catalyst | T (°C) | Conv. (%) | Yield (Sele.) of2-ethylhexanol (%) | TOFb (h−1) |
|---|---|---|---|---|---|
| 1 | – | 170 | – | – | – |
| 2 | 5%Ir-MC-550 | 170 | 3.2 | 1 | 1 |
| 3 | 5%Ir-0.25DMC-550 | 170 | 37.8 | 34.5 (83.1) | 17 |
| 4 | 5%Ir-0.4DMC-550 | 170 | 41.2 | 39.9 (96.7) | 19 |
| 5 | 5%Ir-0.5DMC-550 | 170 | 28.2 | 27.2 (96.5) | 13 |
| 6 | 5%Ir-0.6DMC-550 | 170 | 19 | 16.9 (88.5) | 9 |
| 7 | 5%Ir-0.7DMC-550 | 170 | 18 | 16.5 (91.5) | 8 |
| 8 | 5%Ir-0.4DMC-700 | 170 | 49.8 | 46.5 (93.2) | 23 |
| 9 | 5%Ir-0.4DMC-800 | 170 | 40.8 | 38.4 (94.1) | 19 |
| 10 | 5%Ir-0.4DMC-900 | 170 | 32.6 | 30.7 (94.3) | 15 |
| 11 | 5%Ir-0.4DMC-550 | 150 | 31.7 | 27.3 (86.1) | 15 |
| 12 | 5%Ir-0.4DMC-550 | 190 | 55.3 | 42.8 (77.3) | 25 |
| 13 | 1%Ir-0.4DMC-550 | 170 | 27.5 | 27 (98) | 63 |
| 14 | 3%Ir-0.4DMC-550 | 170 | 44.9 | 43.6 (97.1) | 34 |
| 15c | Reuse entry 4 for 2nd | 170 | 41.8 | 40.2 (96.2) | 19 |
| 16c | Reuse entry 4 for 3rd | 170 | 40.2 | 38.9 (96.9) | 18 |
| 17c | Reuse entry 4 for 4th | 170 | 40.7 | 39.2 (96.3) | 19 |
| 18c | Reuse entry 4 for 5th | 170 | 39.6 | 37.9 (95.6) | 18 |
aReaction conditions: 1 g butanol, 0.1 g iridium catalysts, 1.0 equiv. of NaOH, 15 ml H2O, 17 h.
bTOF = [reacted mol butanol]/[(total mol metal) * (reacton time)].
cThe catalysts were washed with ethanol and water, and then dried for the recycling test.