Isolation and Reactivity of 1,4,2-Diazaborole

An isolable 1,4,2-diazaborole derivative was synthesized and structurally characterized. X-ray diffraction analysis and computational studies revealed a delocalization of 6 pi-electrons over the BC2N2 five-membered ring, which thus indicates the aromatic property. The reactivity toward electrophiles such as MeOTf and selectfluor was also investigated.