Table 1.
Ruthenium‐catalyzed hydrogenative degradation of poly(lactide) (1 a) ‐ optimization of the reaction conditions.
|
| |||||
|---|---|---|---|---|---|
|
Entry[a] |
Catalyst loading [mol %] |
T [°C] |
t [h] |
p [bar] |
Yield 2 [%][b] |
|
1 |
0.5 |
140 |
6 |
45 |
>99 |
|
2 |
0.5 |
140 |
3 |
45 |
>99 |
|
3 |
0.5 |
140 |
1 |
45 |
33 |
|
4 |
0.25 |
140 |
3 |
45 |
32 |
|
5 |
0.1 |
140 |
3 |
45 |
<1 |
|
6 |
0 |
140 |
3 |
45 |
<1 |
|
7 |
0.5 |
120 |
3 |
45 |
67 |
|
8 |
0.5 |
100 |
3 |
45 |
4 |
|
9 |
0.5 |
140 |
3 |
30 |
95 |
|
10 |
0.5 |
140 |
3 |
20 |
<1 |
|
11[c] |
0.5 |
140 |
1 |
45 |
<1 |
|
12[d] |
0.5 |
140 |
1 |
45 |
<1 |
[a] Reaction conditions: poly(lactide) (1 a) (68.2 μmol based on the repeating unit of 1 a), 6 (0–0.5 mol%, 0–0.341 μmol based on the repeating unit of 1 a), THF (1.0 mL), 100–140 °C, 1–6 h, 20–45 bar H2. [b] The yield was determined by 1H NMR. [c] Toluene as solvent. [d] Hexane as solvent.