The use of a bifunctional cinchona/thiourea organocatalyst for the direct and α-stereoselective glycosylation of 2-nitrogalactals is demonstrated for the first time. The conditions are mild, practical, and applicable to a wide range of glycoside acceptors with products being isolated in good to excellent yields. The method is exemplified in the synthesis of mucin type Core 6 and 7 glycopeptides.
首次证明了双功能
金鸡纳/
硫脲有机催化剂用于2-硝基半
乳糖的直接和α-立体选择性糖基化的用途。条件温和,实用,适用于各种糖苷受体,分离产物的收率良好至极佳。该方法在合成粘蛋白型核心6和7糖肽中得到了例证。