Entrya | Catalyst | Temp. (°C) | Conversion (%)b | e.e. (%)c |
---|
1 |
2
| 70 | 21d | 56 |
2 |
3
| 70 | >99 | 49 |
3 |
8
| 70 | 37 | 50 |
4 |
3
| 50 | 14 | 54 |
5 |
4
| 70 | <5 | n.d. |
- aReactions were carried out using 0.5 mol% preformed catalyst and 1 mol% KOtBu at 70°C and 50 bar of hydrogen pressure with a 16 h reaction time unless indicated otherwise. bConversions were determined by 1H NMR analysis of the crude reaction mixtures (all peaks assigned). cThe e.e. value was determined by chiral HPLC (Chiralpak AD-H/Chiralcel OD-H column). The absolute configuration was determined to be S by comparison of optical rotation values with literature values. dBase: catalyst of 50:1 used as is more common with Noyori catalysts.