title: Stereoselective Koenigs-Knorr Glycosylation Catalyzed by Urea.
abstract: A stereoselective Koenigs-Knorr glycosylation reaction under the catalysis of urea is described. This method is characterized by urea-mediated hydrogen-bond activation and subsequent glycosylation with glycosyl chlorides or bromides. Excellent yields and high anomeric selectivity can be achieved in most cases. Moreover, the low α-stereoselectivity of glycosylations observed when using perbenzylated glucosyl donors can be greatly improved by the addition of tri-(2,4,6-trimethoxyphenyl)phosphine (TTMPP).
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road No. 38, Beijing, 100191, China.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road No. 38, Beijing, 100191, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road No. 38, Beijing, 100191, China.
authors.forename: De-Cai
authors.initials: DC
authors.lastname: Xiong
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road No. 38, Beijing, 100191, China. xinshan@bjmu.edu.cn.|National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang, 330022, Jiangxi, China. xinshan@bjmu.edu.cn.
authors.forename: Xin-Shan
authors.initials: XS
authors.lastname: Ye
keywords: carbohydrates; glycosylation; organocatalysis; stereoselectivity; urea