DERIVATIVES OF TETRAHEDRAL BORONIC ACIDS

A series of aliphatic and benzylic bifunctional boronate esters have been prepared as potential ligands for affinity chromatography. Alpha-Acetamido, picolino, thioureido and acetamidino boronates have the hetero atom coordinated with the boron, creating a tetrahedral structure. The H-1, C-13 and B-11 NMR for these compounds confirm the structure, as well as the hetero atom-boron coordination, and show that the bonding of the internal Lewis base with boron increases in order of coordination strength: pyridine < acetamido < thiourea < acetamidine. Bifunctional boronate esters containing these alpha-substituents and phenoxy ether or dimethylaminophenoxy ether groups, which can be coupled to a solid matrix via a diazonium bond, were prepared.