A stable ring-expanded NHC-supported copper boryl and its reactivity towards heterocumulenes

Horsley Downie, Thomas M. and Charman, Rex S. C. and Hall, Jonathan W. and Mahon, Mary F. and Lowe, John P. and Liptrot, David J. (2021) A stable ring-expanded NHC-supported copper boryl and its reactivity towards heterocumulenes. Dalton Transactions, 50 (44). pp. 16336-16342. ISSN 1477-9234 (https://doi.org/10.1039/D1DT03540A)

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Abstract

Reaction of bis(pinacolato)diboron with (6-Dipp)CuOtBu generates a ring-expanded N-heterocyclic carbene supported copper(i) boryl, (6-Dipp)CuBpin. This compound showed remarkable stability and was characterised by NMR spectroscopy and X-ray crystallography. (6-Dipp)CuBpin readily dechalcogenated a range of heterocumulenes such as CO2, isocyanates and isothiocyanates to yield (6-Dipp)CuXBpin (X = O, S). In the case of CO2 catalytic reduction to CO is viable in the presence of excess bis(pinacolato)diboron. In contrast, in the case of iso(thio)cyanates, the isocyanide byproduct of dechalcogenation reacted with (6-Dipp)CuBpin to generate a copper(i) borylimidinate, (6-Dipp)CuC(NR)Bpin, which went on to react with heterocumulenes. This off-cycle reactivity gives selective access to a range of novel boron-containing heterocycles bonded to copper, but precludes catalytic reactivity.

  • Item type:Article
    ID code:89506
    Dates:
    Date
    Event
    31 December 2021
    Published
    26 October 2021
    Published Online
    21 October 2021
    Accepted
    Subjects:
    Science > Chemistry
    Department:Faculty of Science > Pure and Applied Chemistry
    Depositing user: Pure Administrator
    Date deposited:07 Jun 2024 14:35
    Last modified:10 Jun 2024 14:27
    URI:https://strathprints.strath.ac.uk/id/eprint/89506
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