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

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)

[thumbnail of Percy-etal-CAEJ-2015-Developing-the-Saegusa-Ito-cyclisation-for-the-synthesis]
Preview
 Text. Filename: Percy_etal_CAEJ_2015_Developing_the_Saegusa_Ito_cyclisation_for_the_synthesis.pdf
Accepted Author Manuscript
Download (2MB)| Preview

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
CORE (COnnecting REpositories)