Synthesis and structural investigation of two potential boronate affinity chromatography ligands catechol phenylboronate and catechol phenylboronate

Article abstract of DOI:10.1016/0022-328X(94)05337-B

Two potential boronate affinity chromatography ligands, catechol <2-(diisopropylamino)carbonyl>phenylboronate (I) and catechol <2-(diethylamino)carbonyl,4-methyl>phenylboronate (II) were synthesized by directed ortholithiation followed by boronation.Single crystal X-ray analyses of compounds I and II demonstrated an internal coordination bond between the boron atom and the carbonyl oxygen atom, rendering the boron atom environment to be tetrahedral.In addition, 11B NMR data also indicated that the boron environment is tetrahedral.The coordinated carbonyl oxygen-B bond length is 1.556(9) Angstroem compared to an average B-O bond length of 1.47 Angstroem to the catechol ligand.They are ideal models of a new type of ligands to study boronate affinity chromatography because they may esterify with catechols at neutral pH conditions. Keywords: Boron; Boronate; Boronic acid; Crystal structure; Chromatography