Developing the Saegusa-Ito cyclisation for the synthesis of difluorinated cyclohexenones

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Percy, Jonathan M. and McCarter, Adam W. and Sewell, Alan L. and Sloan, Nikki and Kennedy, Alan R. and Hirst, David J. (2015) Developing the Saegusa-Ito cyclisation for the synthesis of difluorinated cyclohexenones. Chemistry - A European Journal, 21 (52). 19119–19127. ISSN 1521-3765 (https://doi.org/10.1002/chem.201503653)

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Abstract

Palladium(II)-catalysed cycloalkenylation (Saegusa-Ito cyclisation) has been used for the first time to transform difluorinated silylenol ethers to difluorinated cycloalkenones under mild conditions. The silylenol ether precursors were prepared in two high-yielding steps from trifluoroethanol, and cyclised in moderate to good yields. A combination of air and copper(I) chloride in acetonitrile achieved the turnover of the initial palladium(II) salt, while the provision of an oxygen atmosphere ensured more rapid reaction. Annulations required a minimum level of substitution on the chain, but failed when the alkene was substituted. Annelations allowed a range of n,6-bicyclic systems to be prepared and afforded three products in which heterocycles were fused to the new cyclohexenone. The least substituted system explored underwent cyclisation followed by terminal oxidation to a cyclic enal, which corresponded to a Wacker product of unusual regiochemistry.

ORCID iDs

Percy, Jonathan M. ORCID logoORCID: https://orcid.org/0000-0001-8636-2704, McCarter, Adam W. ORCID logoORCID: https://orcid.org/0000-0003-4794-110X, Sewell, Alan L., Sloan, Nikki, Kennedy, Alan R. ORCID logoORCID: https://orcid.org/0000-0003-3652-6015 and Hirst, David J.;
  • Item type:Article
    ID code:54720
    Dates:
    Date
    Event
    21 December 2015
    Published
    13 November 2015
    Published Online
    16 October 2015
    Accepted
    Notes:This is the peer reviewed version of the following article: Percy, J. M., McCarter, A. W., Sewell, A. L., Sloan, N., Kennedy, A. R. and Hirst, D. J. (2015), Developing the Saegusa–Ito Cyclisation for the Synthesis of Difluorinated Cyclohexenones. Chem. Eur. J., 21: 19119–19127, which has been published in final form at http://dx.doi.org/10.1002/chem.201503653
    Subjects:Science > Chemistry
    Department:Faculty of Science > Pure and Applied Chemistry
    Depositing user: Pure Administrator
    Date deposited:11 Dec 2015 01:19
    Last modified:11 Nov 2024 11:13
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/54720
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