Boronate derivatives of bioactive amines: potential neutral receptors for anionic oligosaccharides

Oligomeric δ-aminoboronates were synthesized via reductive amination of o-formylbenzene boronic acid with several polymines. The process entails the direct addition of o-formylbenzene boronic acid to the polyamine in methanol at room temperature followed by reduction of the resulting imine with NaBH4. Di-, tri-, and tetrameric δ-aminoboronates have been prepared in this manner and these are anticipated to have enhanced affinities for certain oligosaccharides. A novel templating method for the synthesis of these compounds is also described.