Table 1.
| ||||||
---|---|---|---|---|---|---|
entry | R | X | time [h] | pyrrolidine | yield [%][a] | ee [%][b] |
1 | Bn | SbF6 | 5 | 3a | 100[c] | 29 |
2 | Cbz | ClO4 | 48 | 3b | 99 | 79 |
3 | Boc | ClO4 | 48 | 3c | 97 | 80 |
4[d] | Troc | ClO4 | 48 | 3d | 62 | 84 |
5 | CO2Me | ClO4 | 48 | 3e | 97 | 75 |
6 | Ts | ClO4 | 48 | 3f | 98 | 76 |
7 | Fmoc | ClO4 | 48 | 3g | 95 | 91 |
Isolated yield.
Determined by HPLC analysis on chiral support.
Conversion.
Reaction run at 40 °C.