KINETIC RESOLUTION OF THE CHIRAL IRON ACETYL COMPLEXES [FE(CO)(ETA(5)-C5H5)-(L)COCH3] [L=PPH(3), P(P-TOLYL)(3)] VIA ALDOL REACTIONS WITH CAMPHOR
The chiral iron acetyl complexes [Fe(CO)(η5-C 5H5)(L)COCH3] [L = PPh3, P(p-tolyl)3] have been kinetically resolved via aldol reactions involving their derived lithium enolates and camphor in the presence of lithium chloride. With (1R)-(+)-camphor the faster reacting iron acetyl enantiomer had the (S...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
1994
|
| Summary: | The chiral iron acetyl complexes [Fe(CO)(η5-C 5H5)(L)COCH3] [L = PPh3, P(p-tolyl)3] have been kinetically resolved via aldol reactions involving their derived lithium enolates and camphor in the presence of lithium chloride. With (1R)-(+)-camphor the faster reacting iron acetyl enantiomer had the (S)-configuration allowing the (R)-iron acetyls to be obtained after recovery of starting material and crystallisation. The corresponding (S)-iron acetyls can be obtained by a base-promoted reverse aldol reaction of the isolated products. A mechanistic rationale for the high enantiomeric discrimination is proposed which involves a chelation-controlled chair transition state with a disfavourable 1 -methyl to cyclopentadienyl interaction in the mismatched pairing. |
|---|