Highly efficient stereospecific preparation of Tn and TF building blocks using thioglycosyl donors and the Ph2SO/Tf2O promotor system
Highly efficient stereospecific preparation of Tn and TF building blocks using thioglycosyl donors and the Ph2SO/Tf2O promotor system
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DOI：
10.1081/car-200067091
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发表时间：
2005-05-01
影响因子：
1
通讯作者：
Boons, GJ
中科院分区：
文献类型：
--
作者：
Cato, D;Buskas, T;Boons, GJ
2-叠氮基-2-脱氧Tn和TF巯基糖基的活化。研究了Ph_2SO/Tf_2O体系作为强亲硫助催化剂对供体的催化作用。Fmoc保护的苏氨酸衍生物的糖基化得到高产率和优异的立体选择性的1，2-顺式糖苷。用带有2-O-（2，5-二氟苯甲酰基）的三氯乙酰亚胺酯作供体，使苯基2-叠氮基-4，6-O-亚苄基-2-脱氧-1-硫代-β-吡喃半乳糖苷发生半乳糖基化反应，产率高，不生成原酸酯。所构建的TF二糖的异头噻吩基可被货车Boom启动子直接激活，用于苏氨酸衍生物的糖基化。
The activation of 2-azido-2-deoxy Tn and TF thioglycosyl. donors by the powerful thiophilic promoter system Ph2SO/Tf2O has been investigated. Glycosylation of an Fmoc-protected threonine derivative gave 1,2-cis glycosides in high yields and excellent stereoselectivities. The galactosylation of phenyl 2-azido-4,6-O-benzylidene-2-deoxy-1-thio-beta--galactopyranoside was achieved in high yield and without orthoester formation using a trichloroacetimidate donor carrying a 2-O-(2,5-difluorobenzoyl) group. The anomeric thiophenyl group of the constructed TF disaccharide could directly be activated by the van Boom promotor for the glycosylation of a threonine derivative.