Mechanistic studies of the molybdenum-catalyzed asymmetric alkylation reaction
Hughes, DL; Lloyd-Jones, GC; Krska, SW; Gouriou, L; Bonnet, VD; Jack, K; Sun, Y; Mathre, DJ; Reamer, RA
| HERO ID | 4559723 |
|---|---|
| In Press | No |
| Year | 2004 |
| Title | Mechanistic studies of the molybdenum-catalyzed asymmetric alkylation reaction |
| Authors | Hughes, DL; Lloyd-Jones, GC; Krska, SW; Gouriou, L; Bonnet, VD; Jack, K; Sun, Y; Mathre, DJ; Reamer, RA |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 101 |
| Issue | 15 |
| Page Numbers | 5379-5384 |
| Abstract | Enantiomerically enriched, deuterated branched carbonates (Z)-(S)-PhCH(OCO(2)Me)-CH = CHD (1-D), (Z)-(R)-PhCH(OCO(2)Me)CH = CHD (2-D), and linear carbonate (E)-(S)-PhCH = CHCHD(OCO(2)Me) (3-D) were used as probes in the Mo-catalyzed asymmetric allylic alkylation with sodium dimethyl malonate, catalyzed by ligand-complex 11 derived from the mixed benzamide/picolinamide of (S,S)-transdiaminocyclohexane and (norbornadiene)Mo(CO)(4). The results of these studies, along with x-ray crystallography and solution NMR structural analysis of the pi-allyl intermediate, conclusively established the reaction proceeded by a retention-retention pathway. This mechanism contrasts with that defined for Pd-catalyzed allylic alkylations, which proceed by an inversion-inversion pathway. A proposed rationale for the retention pathway for nucleophilic substitution involves CO-coordination to form a tri-CO intermediate, followed by complexation with the anion of dimethyl malonate to produce a seven-coordinate intermediate, which reductively eliminates to afford product with retention of configuration. |
| Doi | 10.1073/pnas.0306918101 |
| Pmid | 15056759 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |
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