Table 1. Exploration of CAT Reagents for the Synthesis of Nonracemic α-Trialkyl-α-tertiary Amines.
| entry | CAT reagent | e.r.a | yield (%)b |
|---|---|---|---|
| 1 | 4a | 81:19 | 70 |
| 2 | 4b | 84:16 | 68 |
| 3 | 4c | 82:18 | 46 |
| 4 | 4d | 82:18 | 24 |
| S | 4e | 10:90 | 52 |
| 6 | 4f | – | – |
| 7 | 4g | 73:27 | 47c |
| 8 | 4h | 32:68 | >90c |
a
Enantiomeric ratio determined via derivatization to benzoylated amine and separation using chiral HPLC.
b
Yields determined by 1H NMR relative to 1,1,2,2-tetrachloroethane internal standard.
c
Yield determined via consumption
of phenyl vinyl sulfone as determined by 1H NMR relative
to 1,1,2,2-tetrachloroethane internal standard.