Mechanisms and Origins of Periselectivity of the Ambimodal [6 + 4] Cycloadditions of Tropone to Dimethylfulvene.
The mechanisms and selectivities of the cycloadditions of tropone to dimethylfulvene have been investigated with M06-2X and B3LYP-D3 density functional theory (DFT) calculations and quasi-classical direct molecular dynamics simulations. The originally proposed reaction mechanism (Houk) involves a hi...
| Publicado en: | Journal of the American Chemical Society Vol. 139; no. 24; pp. 8251 - 8259 |
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| Autores principales: | , , , , , , , |
| Formato: | Artículo |
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American Chemical Society
6/21/2017
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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=125107933&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 125107933 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: 6/21/2017 vid: 139 iid: 24 pid: 997 pub: American Chemical Society artinfo: ui: 125107933 10.1021/jacs.7b02966 ppf: 8251 ppct: 8 formats: tig: atl: Mechanisms and Origins of Periselectivity of the Ambimodal [6 + 4] Cycloadditions of Tropone to Dimethylfulvene. aug: au: Yu, Peiyuan Chen, Tiffany Q. Yang, Zhongyue He, Cyndi Qixin Patel, Ashay Lam, Yu-hong Liu, Ching-Yang Houk, K. N. affil: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States Department of Applied Chemistry, Chinese Culture University, Taipei, Taiwan 11114, R O. C. su: Tropones Ring formation (Chemistry) Density functional theory Molecular dynamics Chemical adducts sug: subj: Tropones Ring formation (Chemistry) Density functional theory Molecular dynamics Chemical adducts ab: The mechanisms and selectivities of the cycloadditions of tropone to dimethylfulvene have been investigated with M06-2X and B3LYP-D3 density functional theory (DFT) calculations and quasi-classical direct molecular dynamics simulations. The originally proposed reaction mechanism (Houk) involves a highly peri-, regio-, and stereoselective [6 + 4] cycloaddition of tropone [4n] to dimethylfulvene [6n], followed by a [1,5] hydrogen shift, and, finally, a second [6 + 4] cycloaddition of tropone [6n] to the cyclopentadiene moiety [4n]. Paddon-Row and Warrener proposed an alternative mechanism: the initial cycloaddition involves a different [6 + 4] cycloaddition in which fulvene acts as the 4n component, and a subsequent Cope rearrangement produces the formal [6 + 4] adduct. Computations now demonstrate that the initial cycloaddition proceeds via an ambimodal transition state that can lead to both of the proposed [6 + 4] adducts. These adducts can interconvert through a [3,3] sigmatropic shift (Cope rearrangement). Molecular dynamics simulations reveal the initial distribution of products and provide insights into the time-resolved mechanism of this ambimodal cycloaddition. Competing [4 + 2] cycloadditions and various sigmatropic shifts are also explored. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2017 holdings: @attributes: islocal: N |
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