Sugar complexation using boronic acids

From the known, differential complexing between boronic acids and polyhydroxy compounds, it follows that carbohydrate mixtures may be separated by column-chromatographic methods that exploit the differences. Nucleoside and nucleotide boronates have been separated on columns of anion-exchange resins,90 and sugars and alditols have been shown to be differentially retained on such resins in the sulfonated phenylboronic acid form,64 but perhaps the best uses of column chromatography in this connection have incorporated the resolving powers of insoluble polymers to which boronic acid groups have been covalently bonded. Such insoluble forms of boronates have been synthesized either by substitution of polysaccharide derivatives, or by polymerization of suitable arylboronic acids. 

The complexation of aldoses with cholesterol-derived boronic acids has been reviewed, and the changes in UV absorption and fluorescence intensity of a stilbene-type boronic acid on complexation with aldoses, especially D-fructose, have been studied with a view to their use in sugar-detection. Similar work has been carried out with diboronic acids derived from biphenyl and a -functionalized diaza-18-C-6 crown ether.A carbohydrate boronic acid derivative with liquid crystal properties referred to in Chapter 6, and further reports on boronate esters are noted in Chapter 17. 

Cholesteryl arylboronic acid derivatives have been used to extract sugars into organic solvents, and the aldose-cholesteryl boronic acid complexation results in a UV-visible absorption shift characteristic of the aldose enantiomer used. ... 

Ishi-i has investigated homogeneous imprinting (0-D), [60]fullerene was used as an imprinting base. Two moles of a boronic acid of 1,2-Z w(bromomethyl)benzene form a complex with one mole of sugar and the resultant 2 1 complex was allowed to react with [60]fullerene in a homogeneous solution (Scheme 48). The... 

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