Table 1.
Catalytic enantioselective synthesis of oxygen heterocycles by chiral bidentate and monodentate phosphines.
 | |||
|---|---|---|---|
| entry | cat. | ee (%)[a] | yield (%)[b] |
| 1 | (S,S)-CHIRAPHOS | - | <2 |
| 2 | (R,R)-DIPAMP | 22 | 70 |
| 3 | (R,R)-Me-DUPHOS | - | <2 |
| 4 | (R,R)-BINAPHANE | 17 | 9 |
| 5 | (R)-MOP | - | <2 |
| 6 | (S)-MONOPHOS | - | <2 |
| 7 | (S)-4 | −66 | 72 |
| 8 | (S)-5 | −45 | 65 |
| 9 | (S)-1 | 87 | 80 |
All data are the average of two experiments.
[a]
A negative value for the ee signifies that the enantiomer of 3 is formed preferentially.
[b]
The yield was determined by GC analysis with the aid of a calibrated internal standard.