Table 2. Homo- and Heterodinuclear CHO/CO2 ROCOP Catalysts Using L1a.
| # | catalyst | p(CO2) (bar) | conv.b (%) | CO2c (%) | polym.d (%) | TONe | TOF (h–1)f |
|---|---|---|---|---|---|---|---|
| 1 | Mg(II)Mg(II) | 1 | 18 | >99 | >99 | 368 | 368 |
| 2 | Co(II)Co(II) | 1 | 36 | >99 | 96 | 712 | 712 |
| 3 | Mg(II)Co(II) | 1 | 25 | >99 | 99 | 502 | 1205 |
| 4 | Mg(II)Mg(II) | 20 | 91 | >99 | >99 | 1820 | 1060 |
| 5 | Co(II)Co(II) | 20 | 94 | >99 | >99 | 1880 | 4200 |
| 6 | Mg(II)Co(II) | 20 | 95 | >99 | >99 | 1900 | 7200 |
| 7g | Mg(II)Co(II) | 20 | 96 | >99 | >99 | 1920 | 12460 |
a
Reaction conditions: [Cat]/[trans-1,2-cyclohexane diol (CHD)]/[CHO] = 1:20:2000, neat epoxide, 120 °C.
b
Conversion of epoxide, determined by 1H NMR.
c
Selectivity for carbonate vs ether, determined by 1H NMR.
d
Selectivity for polymer vs cyclic carbonate, determined by 1H NMR.
e
Turnover number (TON) = total number of moles of epoxide consumed/mol of catalyst.
f
Turnover frequency (TOF) = TON/time (hours).
g
[Cat]/[CHD]/[CHO] = 1:20:2000, 3 M CHO in diethylcarbonate, 140 °C.2