Table 2.
Entry | Additional ligand | Yield (%) 3 | er (S:R) |
---|---|---|---|
1 | TMEDA | 73 | 80:20 |
2 | TMEDA (0.1 equiv.) | 68 | 80:20 |
3 | TMEDA (2 equiv.) | 59 | 77:23 |
4 | none | <10 | 50:50 |
5 | Et3N | 11 | 50:50 |
6 | (−)-sparteine 1 | 27 | 50:50 |
7 | PMDTA | 56 | 59:41 |
8 | Me2NCH2CH2OLi | 31 | 53:47 |
9 | TEEDA | 8 | 83:17 |