Regioselective glycosylation of fully unprotected sugars by means of molecular recognition using arylboronic acid

该方法适用于糖结构与芳基硼酸的分子识别，其中5-元硼酸酯从1，2-顺式-二羟基基团，或6-元硼酸酯从1，3-二羟基基团。正如预期的那样，糖基化发生在没有硼酸盐形成的左羟基上，然后通过水处理原位除去硼酸盐，以一锅法产生各种二糖。例如，D-葡萄糖、D-半乳糖、D-甘露糖经硼酸化后，分别与苯基全-O-苯甲酰基-1-硫代-β-D-葡萄糖苷、-β-D-半乳糖苷和-α-D-甘露糖苷在促进剂存在下进行糖基化（NIS-TMSOTf）以提供相应的二糖;糖基-β（1→6）-D-葡萄糖、-β（1→6）-D-半乳糖、-βα（1，1）-D-甘露糖苷的合成方法具有较好的产率，这可能有助于简单的、一锅法制备各种生物学目的寡糖。

The methodology is adapted to molecular recognition of sugar structures with arylboronic acids, which from 5-membered boronates from 1,2-cis-dihydroxy groups, or 6-membered boronates from 1,3-dihydroxy groups. As expected glycosylation occurs on the left hydroxy group free from the boronate formation, and then the boronates are removed in situ by aqueous workup to yield various disaccharides in one-pot process.Various hexoses. eg., D-glucose, D-galactose, D-mannose were glycosylated, after boronate formation, with phenyl per-O-benzoyl-1-thio-β-D-glucopyranoside, -β-D-galactopyranoside and -α-D-mannopyranoside in the presence of promoters (NIS-TMSOTf) to furnish corresponding disaccharides ; glycosyl-β(1→6)-D-glucose, -β(1→6)-D-galactose, -βα(1,1)-D-mannoside in good yields.This method would be of significance with respect to regio- and stereoselecyive glycosylation, which might contribute to simple, one-pot preparation of various oligosaccharides of biological interest.