Table 2. Summary of High-Throughput Catalyst Screening for the Asymmetric Reduction of 17.
| entry | reductant | cat | conditions | HPLC area % | % ee |
|---|---|---|---|---|---|
| 1 | H2 (3 MPa) | 27 | tBuOK (10 equiv), MeOH, 40 °C | 25.9 | 100 |
| 2 | H2 (3 MPa) | 28 | nBu4NI (10 equiv), AcOH/toluene 40 °C | 93.5 | 34.2 |
| 3 | H2 (3 MPa) | 29 | MeOH/THF, 40 °C | 82.3 | 85.5 |
| 4 | HCOOH (6 equiv) | 30 | Et3N (2.4 equiv), DMF, rt | 89.1 | 82.7 |
