Specific complexation of disaccharides with diphenyl-3,3′-diboronic acid that can be detected by circular dichroism

For the development of new receptor molecules that can recognize sugar molecules, we synthesized diphenyl-3,3′-diboronic acid (2). The distance between the two boronic acids in 2 is designed so that it can selectively form cyclic 1:1 complexes with disaccharides. It was shown that 2 forms 1:1 complexes with several disaccharides and gives the characteristic exciton coupling in CD spectroscopy owing to immobilization of the two phenyl rings. Thus, the absolute configuration was successfully predicted from the sign of the exciton coupling.