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]