X-ray crystallographic studies of bond-delocalization in 1,2-dihydro-1,2-azaborines

ORGN 398

Shih-Yuan Liu, lsy@uoregon.edu and Eric R. Abbey, eabbey@uoregon.edu. Department of Chemistry, University of Oregon, 1253 University of Oregon, Eugene, OR 97403
The aromaticity of 1,2-dihydro-1,2-azaborines has been a subject of interest since the 1960's, with theoretical studies suggesting significant aromatic stabilization of these heterocycles. Experimental characterization of this delocalization (e.g., bond length homogeneity, enthalpy of hydrogenation) have been limited. Recent synthetic advances have allowed exploration of the aromatic properties of 1,2-dihydro-1,2-azaborines on a more tangible level. The crystal structures for a series of six-membered boron-nitrogen heterocycles differing only in their degree of conjugation will be presented. These data allow an experimental evaluation of the aromaticity of 1,2-dihydro-1,2-azaborines.