CARB 19 |
| Boronic-acids are well known functional groups for the molecular recognition of diol containing structures. We have undertaken a structural study of o-(pyrrolidinylmethyl)phenylboronic acid and its complexes with bifunctional substrates such as catechol, a-hydroxyisobutyric acid, and hydrobenzoin in detail by x-ray crystallography, 11B NMR, and computational analysis. Our study predicts that the formation of an N-B dative bond, and/or solvolysis to afford a tetrahedral boronate anion, depends on the solvent and the complexing substrate present. Specifically, from 11B NMR studies, complexation with electron withdrawing and/or vicinally bifunctionalized substrates promotes both the formation of N-B dative bonds and the solvation of sp2 boron to a tetrahedral sp3 boronate. The conclusion has assisted us in the design of chemosensing technologies based on o-(N,N-dialkylaminomethyl)arylboronate scaffolds. In that regard, we have extensively used boronic acids in molecular recognition schemes for sensing the chirality of diol-containing structures using colorimetric methods. Both the structural analysis and the assay for enantiomeric excess will be discussed in this presentation. |
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Carbohydrate Recognition Mechanisms and Applications
9:00 AM-12:15 PM, Tuesday, 28 March 2006 Georgia World Congress Center -- B409, Oral
Division of Carbohydrate Chemistry |