Table 2.
| ||||
---|---|---|---|---|
entry | R1 | R2 | yielda (%) | eeb (%) |
1 | Ph | Ph | 70 (5) | 93 |
2 | 4-Me–C6H4 | Ph | 71 (6) | 90 |
3 | 4-Br–C6H4 | Ph | 68 (7) | 84 |
4 | 4-MeO-C6H4 | Ph | 62 (8) | 90 |
5 | 2-naphthyl | Ph | 69 (9) | 81 |
6 | cyclohexyl | Ph | 0 | |
7 | Ph | 4Cl-Ph | 80 (10) | 93 |
Isolated yields.
Enantiomeric excess determined by HPLC Chiracel OD-H or AD-H. Diastereomeric ratio determined by 1H NMR spectroscopy (500 MHz).