Research

Stoichiometric and catalytic reactivity of tert-butylamine-borane with calcium silylamides


Reference:

Bellham, P., Hill, M. S. and Kociok-Köhn, G., 2014. Stoichiometric and catalytic reactivity of tert-butylamine-borane with calcium silylamides. Organometallics, 33 (20), pp. 5716-5721.

Related documents:

[img]
Preview
PDF (Primary amine boranes_revised) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (584kB) | Preview

    Official URL:

    http://dx.doi.org/10.1021/om500467b

    Related URLs:

    Abstract

    The primary amine-borane t-BuNH2·BH3 reacts with a β-diketiminate-supported silylamido calcium complex with elimination of HN(SiMe3)2 and formation of the corresponding primary amidoborane complex, in which the deprotonated amine-borane is attached to the alkaline-earth center via its nitrogen atom and anagostic interactions with the boron-bound hydrides. Catalytic dehydrocoupling reactions employed with this β-diketiminate precatalyst are found to be slow and complicated by protonation of the supporting ligand and the formation of a number of boron-containing products, all of which have been positively identified. In common with previous studies of group 2 catalyzed secondary amine-borane dehydrogenation, the first formed major product of the catalysis is identified by solution NMR and solid-state single-crystal X-ray studies to be a cyclic diborazane, [HtBuN-BH2]2, the formation of which is accompanied by variable proportions of diamidoborane and aminoborane products. The active calcium species is also observed to be depleted during the catalysis due to the formation of hydrocarbon-insoluble [Ca(BH4)2·THF]∞, which has also been structurally characterized. Continued heating of these reaction mixtures results in the formation of cyclic trimeric 1,3,5-tri-tert-butylborazine, which is proposed to form through the intermediacy of [HtBuN-BH2]2 by an, as yet, undefined sequence of borazane dehydrogenation and ring expansion reactions.

    Details

    Item Type Articles
    CreatorsBellham, P., Hill, M. S. and Kociok-Köhn, G.
    DOI10.1021/om500467b
    Related URLs
    URLURL Type
    http://www.scopus.com/inward/record.url?scp=84908637030&partnerID=8YFLogxKUNSPECIFIED
    DepartmentsFaculty of Science > Chemistry
    Research CentresCentre for Sustainable Chemical Technologies
    Publisher StatementPrimary_amine_boranes_revised.pdf: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organometallics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/om500467b.
    RefereedYes
    StatusPublished
    ID Code42524

    Export

    Actions (login required)

    View Item

    Document Downloads

    More statistics for this item...