Shadrick Melanie, Singh Yashapal, Demchenko Alexei V
Department of Chemistry and Biochemistry, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri 63121, United States.
J Org Chem. 2020 Dec 18;85(24):15936-15944. doi: 10.1021/acs.joc.0c01279. Epub 2020 Oct 16.
A recent discovery of a cooperative catalysis comprising a silver salt and an acid led to a dramatic improvement in the way glycosyl halides are glycosidated. Excellent yields have been achieved, but the stereoselectivity achieved with 2--benzylated donors was poor. Reported herein is our first attempt to refine the stereoselectivity of the cooperatively catalyzed galactosylation reaction. Careful optimization of the reaction conditions along with studying effects of the remote protecting groups led to excellent stereocontrol of α-galactosylation of a variety of glycosyl acceptors with differentially protected galactosyl donors.
最近发现银盐和酸组成的协同催化作用极大地改进了糖基卤化物的糖基化方式。已实现了优异的产率，但2-苄基供体的立体选择性较差。本文报道了我们首次尝试优化协同催化的半乳糖基化反应的立体选择性。通过仔细优化反应条件并研究远程保护基的影响，实现了对多种具有不同保护基的半乳糖基供体与各种糖基受体的α-半乳糖基化反应的优异立体控制。
