Axial Chirality about Boron-Carbon Bond: Atropisomeric Azaborines.

The preparation of atropisomeric 2,1-borazaronaphthalenes is described. Resolution of the atropisomeric pair was achieved by preparative Chiral Stationary Phase HPLC (CSP-HPLC). The absolute configuration of the stereogenic axis was derived from Time-Dependent DFT (TD-DFT) simulation of the Electronic Circular Dichroism spectra (ECD). X-ray diffraction and Dynamic NMR data allowed structural and dynamic comparison with the analogue isosteric carbon compounds.