Regioselective and 1,2-cis-α-stereoselective glycosylations using 1α,2α-anhydro glycosyl donors and diol glycosyl acceptors in the presence of a glycosyl-acceptor-derived boronic ester catalyst. The reactions proceed smoothly to give the corresponding 1,2-cis-α-glycosides with high stereo- and regioselectivities in high yields without any further additives under mild reaction conditions. In addition, the present glycosylation method was successfully applied to the synthesis of an isoflavone glycoside.

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Regioselective and 1,2-cis-a-stereoselective glycosylations using 1a,2a-anhydro glycosyl donors and diol glycosyl acceptors in the presence of ag lycosyl-acceptor-derived boronic ester catalyst. The reactions proceed smoothly to give the corresponding 1,2-cis-a-glycosides with high stereoand regioselectivities in high yields without any further additives under mild reaction conditions.I na ddition, the present glycosylation method was successfully applied to the synthesis of an isoflavone glycoside.

Regioselective and 1,2-cis--Stereoselective Glycosylation Utilizing Glycosyl--Acceptor-Derived Boronic Ester Catalyst. -Various 1,2-anhydro glycosyl donors such as (I) react with diol glycosyl acceptors in the presence of a boron catalyst, derived in situ from the acceptor component and the boronic acid in the reaction medium. The procedure can be carried out under mild conditions in the absence of any additive and is also used for the synthesis of higher saccharides and an isoflavone glycoside. -(NAKAGAWA, A.; TANAKA, M.; HANAMURA, S.; TAKAHASHI*, D.; TOSHIMA, K.; Angew. Chem., Int. Ed. 54 (2015) 37, 10935-10939, http://dx.