Alkaline-Earth Derivatives of the Reactive [HB(C6F5)3]- Anion

Mathew D. Anker, Merle Arrowsmith, Rory L. Arrowsmith, Michael S. Hill, Mary F. Mahon

Research output: Contribution to journalArticle

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Abstract

The β-diketiminato magnesium amidoboranes [HC{(Me)CNDipp}2Mg(NMe2BH2NMe2·BH3)] and [HC{(t-Bu)CNDipp}2Mg(NMe2·BH3)] are readily converted to the corresponding derivatives of the [HB(C6F5)3]- anion by treatment with B(C6F5)3. The bis(borohydride) derivatives of the heaviest alkaline-earth elements, strontium and barium, may be similarly synthesized by reaction of strontium or barium dimethylamidoboranes and B(C6F5)3 and by metathesis reactions of either SrI2 or BaI2 and 2 molar equiv of K(HB(C6F5)3). The strontium and barium compounds have been fully characterized in solution and in the solid state as the respective tris(diethyl ether) and tetrakis(tetrahydrofuran) adducts. The magnesium compound [HC{(Me)CNDipp}2Mg(HB(C6F5)3)] has been applied to the catalytic hydroboration of i-PrN=C=N-i-Pr with HBpin. In contrast to carbodiimide hydroboration catalyzed by the corresponding β-diketiminato magnesium hydride, which results in the exclusive production of the monoborylated amidine, use of the [HB(C6F5)3]- derivative provides the product of bis-borylation, the aminal H2C(N{Bpin}i-Pr)2, under mild conditions. A series of stoichiometric reactions highlight that, while this reactivity is likely to be primarily magnesium mediated, B(C6F5)3 plays a vital role both in the delivery of reactive hydride and through the Lewis acid activation of the heteroallene substrate and various reactive intermediates.

LanguageEnglish
Pages5976-5983
Number of pages8
JournalInorganic Chemistry
Volume56
Issue number10
DOIs
StatusPublished - 15 May 2017

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hydroboration
Magnesium
Anions
magnesium
Strontium
Earth (planet)
Barium
anions
Derivatives
Hydrides
strontium
Barium Compounds
hydrides
Strontium compounds
barium
Magnesium Compounds
strontium compounds
barium compounds
magnesium compounds
Amidines

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this

Alkaline-Earth Derivatives of the Reactive [HB(C6F5)3]- Anion. / Anker, Mathew D.; Arrowsmith, Merle; Arrowsmith, Rory L.; Hill, Michael S.; Mahon, Mary F.

In: Inorganic Chemistry, Vol. 56, No. 10, 15.05.2017, p. 5976-5983.

Research output: Contribution to journalArticle

Anker, MD, Arrowsmith, M, Arrowsmith, RL, Hill, MS & Mahon, MF 2017, 'Alkaline-Earth Derivatives of the Reactive [HB(C6F5)3]- Anion' Inorganic Chemistry, vol. 56, no. 10, pp. 5976-5983. DOI: 10.1021/acs.inorgchem.7b00678
Anker MD, Arrowsmith M, Arrowsmith RL, Hill MS, Mahon MF. Alkaline-Earth Derivatives of the Reactive [HB(C6F5)3]- Anion. Inorganic Chemistry. 2017 May 15;56(10):5976-5983. Available from, DOI: 10.1021/acs.inorgchem.7b00678
Anker, Mathew D. ; Arrowsmith, Merle ; Arrowsmith, Rory L. ; Hill, Michael S. ; Mahon, Mary F./ Alkaline-Earth Derivatives of the Reactive [HB(C6F5)3]- Anion. In: Inorganic Chemistry. 2017 ; Vol. 56, No. 10. pp. 5976-5983
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