Multinuclear NMR Study of the Reactive Intermediates in Enantioselective Epoxidations of Allylic Alcohols Catalyzed by a Vanadium Complex Derived from a Planar-Chiral Hydroxamic Acid Full article
| Journal |
New Journal of Chemistry
ISSN: 1144-0546 , E-ISSN: 1369-9261 |
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| Output data | Year: 2003, Volume: 27, Number: 3, Pages: 609-614 Pages count : 6 DOI: 10.1039/b208748k | ||||
| Tags | allyl alcohol; carbon 13; epoxide; geraniol; hydroxamic acid; metal complex; oxygen 17; paracyclophane derivative; tert butyl hydroperoxide; vanadium derivative | ||||
| Authors |
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| Affiliations |
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Funding (4)
| 1 | Russian Foundation for Basic Research | 00-03-32438 |
| 2 | International Association for the Promotion of Co-operation with Scientists from the New Independent States of the Former Soviet Union | YSF-006 |
| 3 | German Research Foundation | |
| 4 | Verband der Chemischen Industrie |
Abstract:
Structure and reactivity of vanadium(V) complexes formed in situ in the catalytic system VO(Oalkyl)3/hydroxamic acid/tert-butylhydroperoxide (TBHP) have been examined by means of 51V, 13C and 17O NMR spectroscopy. For the first time, reactive vanadium(V) alkylperoxo intermediates in vanadium/hydroxamic acid epoxidations were observed and spectroscopically characterized. With a planar-chiral [2.2]paracyclophane-derived hydroxamate as ligand two diastereomeric alkylperoxo vanadium(V) complexes were formed in a 3∶1 ratio. They differ in the relative positioning of the V[double bond, length as m-dash]O group and the planar-chiral aromatic part. Upon addition of geraniol as substrate, these complexes disappear in a parallel manner, and geraniol epoxide is formed. Probably, the existence of these two diastereomeric complexes and their comparable reactivity account for the observed enantioselectivity level (≤71% ee) and hence sets a fundamental limitation for the use of such ligands in this asymmetric catalysis.
Cite:
Bryliakov K.P.
, Talsi E.P.
, Kühn T.
, Bolm C.
Multinuclear NMR Study of the Reactive Intermediates in Enantioselective Epoxidations of Allylic Alcohols Catalyzed by a Vanadium Complex Derived from a Planar-Chiral Hydroxamic Acid
New Journal of Chemistry. 2003. V.27. N3. P.609-614. DOI: 10.1039/b208748k WOS Scopus РИНЦ ANCAN OpenAlex
Multinuclear NMR Study of the Reactive Intermediates in Enantioselective Epoxidations of Allylic Alcohols Catalyzed by a Vanadium Complex Derived from a Planar-Chiral Hydroxamic Acid
New Journal of Chemistry. 2003. V.27. N3. P.609-614. DOI: 10.1039/b208748k WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Sep 4, 2002 |
| Accepted: | Nov 5, 2002 |
| Published online: | Jan 15, 2003 |
| Published print: | Feb 27, 2003 |
Identifiers:
| Web of science: | WOS:000181210200028 |
| Scopus: | 2-s2.0-0037352252 |
| Elibrary: | 13426818 |
| Chemical Abstracts: | 2003:149731 |
| Chemical Abstracts (print): | 139:117495 |
| OpenAlex: | W2041465935 |