N-heterocyclic carbene-stabilized germa-acylium ion : reactivity and utility in catalytic CO2 functionalizations

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Sarkar, Debotra and Weetman, Catherine and Dutta, Sayan and Schubert, Emeric and Jandl, Christian and Koley, Debasis and Inoue, Shigeyoshi (2020) N-heterocyclic carbene-stabilized germa-acylium ion : reactivity and utility in catalytic CO2 functionalizations. Journal of the American Chemical Society, 142 (36). pp. 15403-15411. ISSN 1520-5126 (https://doi.org/10.1021/jacs.0c06287)

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Abstract

The first acceptor-free heavier germanium analogue of an acylium ion, [RGe(O)(NHC)2]X (R = MesTer = 2,6-(2,4,6-Me3C6H2)2C6H3; NHC = IMe4 = 1,3,4,5-tetramethylimidazol-2-ylidene; X = (Cl or BArF = {(3,5-(CF3)2C6H5)4B}), was isolated by reacting [RGe(NHC)2]X with N2O. Conversion of the germa-acylium ion to the first solely donor-stabilized germanium ester [(NHC)RGe(O)(OSiPh3)] and corresponding heavier analogues ([RGe(S)(NHC)2]X and [RGe(Se)(NHC)2]X) demonstrated its classical acylium-like behavior. The polarized terminal GeO bond in the germa-acylium ion was utilized to activate CO2 and silane, with the former found to be an example of reversible activation of CO2, thus mimicking the behavior of transition metal oxides. Furthermore, its transition-metal-like nature is demonstrated as it was found to be an active catalyst in both CO2 hydrosilylation and reductive N-functionalization of amines using CO2 as the C1 source. Mechanistic studies were undertaken both experimentally and computationally, which revealed that the reaction proceeds via an N-heterocyclic carbene (NHC) siloxygermylene [(NHC)RGe(OSiHPh2)].

ORCID iDs

Sarkar, Debotra, Weetman, Catherine ORCID logoORCID: https://orcid.org/0000-0001-5643-9256, Dutta, Sayan, Schubert, Emeric, Jandl, Christian, Koley, Debasis and Inoue, Shigeyoshi;
  • Item type:Article
    ID code:73614
    Dates:
    Date
    Event
    9 September 2020
    Published
    10 August 2020
    Published Online
    10 August 2020
    Accepted
    Subjects:Science > Chemistry
    Department:Faculty of Science > Pure and Applied Chemistry
    Depositing user: Pure Administrator
    Date deposited:14 Aug 2020 08:40
    Last modified:12 Dec 2024 10:13
    URI:https://strathprints.strath.ac.uk/id/eprint/73614
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