-Phenyl--[()-2-(4,4,5,5-tetra-methyl-1,3,2-dioxaborolan-2-yl)ethen-yl]aniline.

The title compound, CHBNO, has a polarized π-system due to significant resonance between the N-C(H)=C(H)-B and ionic N=C(H)-C(H)=B canonical forms. The dihedral angles between the NCB plane (r.m.s. deviation 0.0223 Å) and the CN (r.m.s. deviation 0.0025 Å) and BCO (r.m.s. deviation 0.0044 Å) planes are 2.51 (12) and 3.09 (19)°, respectively. This indicates the lone pair of the nitro-gen atom and a vacant orbital of the boron atom are conjugated with the central C=C bond. In comparison with the carbazole analogue [Hatayama & Okuno (2012 ▸). E, o84], the C-N and C-B bonds are shorter. The results are well explained by the increase in the contribution of the N=C(H)-C(H)=B canonical form in the title compound.