Covalent molecular imprinting, boronic ester

Figure 6.5 Boronic ester approach to covalent molecular imprinting of PMP using VPMA [26].

The most successful approach in covalent molecular imprinting is probably the coupling of polymerizable boronic acids to hydroxyl groups present on the template to form boronate esters (Figure 2.2). This approach has, for example, been applied to the imprinting of sugars [57-59]. 

An important question in molecular imprinting has been addressed using covalent binding by two boronic acids to what extent can imprinted polymers also bind substances other than the template. For example, are racemates of other substances resolvable In the first experiments on glyceric acid esters 5 with a certain ester as template, imprinted polymers were shown to resolve a whole series of racemates even when the alcohol group in the racemate is varied (methyl, ethyl, benzyl, or 4-nitrophenyl) [39]. Aromatic amino acids were shown to behave similarly. Here, the aromatic group in the racemates can vary. A racemate resolution is possible provided that the rest of the structure remains the same [40]. 

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