Beilstein J. Org. Chem.2013,9, 761–766, doi:10.3762/bjoc.9.86
Holger F. Bettinger Otto Hauler Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72072 Tübingen, Germany 10.3762/bjoc.9.86 Abstract The ring opening of the Dewar form of 1,2-dihydro-1,2-azaborine, 2-aza-3-borabicyclo[2.2.0]hex-5-ene (3) is investigated by theoretical
methods by using multiconfiguration SCF (CASSCF) and coupled cluster theory [CCSD(T)] with basis sets up to polarised quadruple-zeta quality. The title compound was previously reported to form photochemically in cryogenic noble gas matrices from 1,2-dihydro-1,2-azaborine (4). Four reaction paths for the
isomerisation reaction, 22 kcal mol−1, should be high enough for an experimental observation in solution. However, in solution the dimerisation of 3 is computed to have a very low barrier (3 kcal mol−1), and thus 3 is expected to be a short-lived reactive intermediate.
Keywords: ab initio; azaborine; BN
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Graphical Abstract
Scheme 1:
Isomerisation of bicyclo[2.2.0]hexa-1,3-diene, Dewar benzene (1), to benzene (2) and of 2-aza-3-bor...