The Mechanism of the Rhodium(I)-Catalyzed [2 + 2 + 1] Carbocyclization Reaction of Dienes and CO: A Computational Study.
The rhodium(I) catalyzed [2 + 2 + 1] carbocyclization of tethered diene-enes to afford substituted hexahydropentalenones with high levels of diastereoselectivity was modeled using density functional theory. Previously, this transformation was observed to be facile, whereas the analogous bis-ene subs...
| Publicado en: | Journal of the American Chemical Society Vol. 130; no. 17; pp. 5821 - 5831 |
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| Autores principales: | , , |
| Formato: | Artículo |
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American Chemical Society
4/30/2008
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| 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=31931719&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 31931719 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: 4/30/2008 vid: 130 iid: 17 pid: 997 pub: American Chemical Society artinfo: ui: 31931719 10.1021/ja800856p ppf: 5821 ppct: 10 formats: tig: atl: The Mechanism of the Rhodium(I)-Catalyzed [2 + 2 + 1] Carbocyclization Reaction of Dienes and CO: A Computational Study. aug: au: Pitcock Jr., William H. Lord, Richard L. Mu-Hyun Baik affil: Department of Chemistry and School of Informatics, Indiana University, Bloomington, Indiana 47405 su: Rhodium Density functionals Electron distribution Chemical reactions Chemistry education sug: subj: Rhodium Density functionals Electron distribution Chemical reactions Chemistry education ab: The rhodium(I) catalyzed [2 + 2 + 1] carbocyclization of tethered diene-enes to afford substituted hexahydropentalenones with high levels of diastereoselectivity was modeled using density functional theory. Previously, this transformation was observed to be facile, whereas the analogous bis-ene substrate could not be cyclized under any reasonable conditions. To establish a conceptual understanding of the carbocyclization mechanism and to identify the functional role of the diene fragment we analyzed the simulated reaction mechanisms using the two parent systems. We discovered a thus far unrecognized, but intuitively plausible, role of the CO ligand for controlling the electron density at the metal center, which affects the feasibility of oxidative addition and reductive elimination steps that are key components of the mechanism. Our calculations suggest that the diene moiety is unique and required because of its ability to undergo a η η reorganization allowing for the thermoneutral expulsion of one CO ligand, which in turn generates an electron-rich, coordinatively saturated Rh(I) center that can efficiently promote the oxidative addition with a low barrier. A number of functionalization strategies were considered explicitly to derive a rational plan for optimizing the catalysis and to expose the roles of the different components of the reactant—catalyst complex. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2008 holdings: @attributes: islocal: N |
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