Crystal Clear Structural Evidence for Electron Delocalization in 1,2-Dihydro-1,2-azaborines
摘要:
The first examples of "pre-aromatic" 1,2-dihydro-1,2- azaborine heterocycles have been structurally characterized, enabling the direct comparison of delocalized bonds of 1,2-dihydro-1,2-azaborines to their corresponding formal double and single bonds in nonaromatic systems. The crystallographic data provide an unprecedented look into the structural changes that occur in six-membered BN-heterocycles on their road to aromaticity, and they establish with little ambiguity that 1,2-dihydro-1,2-azaborines posse ss delocalized structures consistent with aromaticity.