Diboric acid derivatives

Iwadate N, Suginome M. Differentially protected diboron for regioselective diboration ofalkynes internal-selective cross-coupling ofl-alkene-l,2-diboronic acid derivatives. JAm Chem Soc. 2010 132 2548-2549. 

Borate complexes have been utilized by Brigl and Griiner47 to effect partial esterification. Anhydrous D-glucose and metaboric acid dissolved in acetone give a complex which exhibits the analysis of a diborate. Reaction of the latter with an excess of benzoyl chloride gives 2,6-di-O-benzoyl-D-glucose (XL). D-Mannitol likewise forms a diborate, which produces the 1,6-di-O-benzoyl derivative (XLI) upon benzoylation. In the presence of boric acid, D-glucose diethyl thioacetal yields the 6-benzoate (XLII). In the non-aqueous medium the formation of complexes... 

Synthesis of 2-monoglycerides. Boric acid is recommended for removal of the 1,3-benzylidene group from l,3-benzyUdene-2-acyl glycerols. The derivative is heated in triethyl borate with finely powdered boric acid until conversion to the diborate ester is complete and this is then hydrolyzed with water, for example to 2-monoolein. 

D-Glucosamine and either ammonia, 1,2-ethylenediamine, or 1,10-phenanthroline have been shown to form complexes with Co (III) ions, and the cobalt (ethylenediamine. D-glucosamine) complex is formed from the a-pyranose anonoo of the sugar. Aldose oximes on catalytic hydrogenation afford bis(polyhydroxyalkyl)amines. These compounds and their N-carboxymetbyl derivatives react with borate ions to give maciocyclic diborate esters which can sequester Ca, Cu and Cd ions. The coordination of some divalent transition metal imis to 2-amino-2-deoxy-D-g(ycero-D-gu/o-heptonic acid in aqueous solution has beat studied. ... 

---