Alkene–Carbene Isomerization induced by Borane: Access to an Asymmetrical Diborene
Date of Issue2017
School of Physical and Mathematical Sciences
A 2,3-dihydro-1H-1,2-azaborole derivative 2 was converted to a cyclic (alkyl) (amino)carbene (cAAC) via 1,2-hydrogen migration triggered by boranes to afford cAAC-borane adducts. This procedure allowed us to develop an asymmetrical diborene cAAC·(Br)B═B(Br)·IDip 6, which was isolated and fully characterized. The 11B NMR spectrum, X-ray diffraction analysis and computational studies indicate that π-electrons on the central B2 moiety in 6 are unequivalently distributed, and thus polarized. A complete scission of the B═B double bond in 6 was achieved by the treatment with an isonitrile, which led to the formation of a base-stabilized B,N-containing methylenecyclopropane 7.
Journal of the American Chemical Society
© 2017 American Chemical Society. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of the American Chemical Society, American Chemical Society. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1021/jacs.7b02251].