Rhodium Boryl Complexes in the Catalytic, Terminal Functionalization of Alkanes.
A series of studies have been conducted by experimental and theoretical methods on the synthesis, structures, and reactions of Cp*Rh boryl complexes that are likely intermediates in the rhodium- catalyzed regioselective, terminal functionalization of alkanes. The photochemical reaction of Cp*Rh(n-CM...
| Publicado en: | Journal of the American Chemical Society Vol. 127; no. 8; pp. 2538 - 2553 |
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| Autores principales: | , , , , , , |
| Formato: | Artículo |
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American Chemical Society
3/2/2005
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=16361026&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 16361026 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 3/2/2005 vid: 127 iid: 8 pid: 997 pub: American Chemical Society artinfo: ui: 16361026 10.1021/ja045090c ppf: 2538 ppct: 15 formats: tig: atl: Rhodium Boryl Complexes in the Catalytic, Terminal Functionalization of Alkanes. aug: au: Hartwig, John F. Cook, Kevin S. Hapke, Marko Incarvito, Christopher D. Yubo Fan Webster, Charles Edwin Hall, Michael B. affil: Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107 Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255 su: Aliphatic compounds Alkanes Aromatic compounds Density functionals Nuclear magnetic resonance spectroscopy Spectrum analysis sug: subj: Aliphatic compounds Alkanes Aromatic compounds Density functionals Nuclear magnetic resonance spectroscopy Spectrum analysis ab: A series of studies have been conducted by experimental and theoretical methods on the synthesis, structures, and reactions of Cp*Rh boryl complexes that are likely intermediates in the rhodium- catalyzed regioselective, terminal functionalization of alkanes. The photochemical reaction of Cp*Rh(n-CMe) with pinacolborane (HBpin) generates the bisboryl complex Cp*Rh(H)(Bpin) (2), which reacts with neat HBpin to generate Cp*Rh(H)(Bpin) (3). X-ray diffraction, density functional theory (DFT) calculations, and NMR spectroscopy suggest a weak, but measurable, B-H bonding interaction. Both 2 and 3 dissociate HBpin and coordinate PEt or P(p-Tol) to generate the conventional rhodium(III) species Cp*Rh(PEt)(H)(Bpin) (4) and Cp*Rh[P(p-tol)](Bpin) 5). Compounds 2 and 3 also react with alkanes and arenes to form alkyl- and arylboronate esters at temperatures similar to or below those of the catalytic borylation of alkanes and arenes. Further, these compounds were observed directly in catalytic reactions. The enthalpies and free energies for generation of the 16-electron intermediate and for the C-H bond cleavage and B-C bond formation have been calculated with DFT. These results strongly suggest that the C-H bond cleavage process occurs by a metal-assisted u-bond metathesis mechanism to generate a borane complex that isomerizes if necessary to place the alkyl group cis to the boryl group. This complex with cis boryl and alkyl groups then undergoes B-C bond formation by a second a-bond metathesis to generate the final functionalized product. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2005 holdings: @attributes: islocal: N |
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