Skeletal formula of 1,2-dihydro-1,2-azaborine
Ball-and-stick model of the 1,2-dihydro-1,2-azaborine molecule
Preferred IUPAC name
3D model (JSmol)
  • InChI=1S/C4H6BN/c1-2-4-6-5-3-1/h1-6H ☒N
  • C1=CC=CNB1
Molar mass 78.908 g mol−1
Appearance clear, colorless liquid
Melting point −46 to −45 °C.
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

1,2-Dihydro-1,2-azaborine is an aromatic chemical compound with properties intermediate between benzene and borazine. Its chemical formula is C4BNH6. It resembles a benzene ring, except that two adjacent carbons are replaced by nitrogen and boron, respectively.


After decades of failed attempts, the compound was synthesized in 2008 and reported in January 2009.[1][2]

One of the synthetic steps is a ring-closing metathesis (RCM) reaction:[3]

1,2-Dihydro-1,2-azaborine synthesis Marwitz et al. 2009


  1. ^ Stu Borman. "Long-Sought Benzenelike Molecule Created: Aromaticity of organic-inorganic hybrid resembles benzene's." C&EN January 5, 2009 Volume 87, Number 01 p. 11
  2. ^ A. J. V. Marwitz; M. H. Matus; L. N. Zakharov; D. A. Dixon; S.-Y. Liu (January 2009). "A Hybrid Organic/Inorganic Benzene". Angew. Chem. Int. Ed. 48 (5): 973–977. doi:10.1002/anie.200805554. PMID 19105174.
  3. ^ TBS = tert-butyldimethylsilyl, step 2 RCM = ring-closing metathesis using Grubbs' catalyst, step 3 organic oxidation using palladium on carbon, step 4 reduction LiBHEt3, step 5 conversion to piano stool complex as protective group with chromium carbonyl derivative, step 6 cleavage N-TBS bond HF, step 7 deprotection with triphenylphosphine