Synthesis of β‐Glucosides with 3‐
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‐Picoloyl‐Protected Glycosyl Donors in the Presence of Excess Triflic Acid: Defining the Scope
作者:Michael P. Mannino、Alexei V. Demchenko
DOI:10.1002/chem.201905278
日期:2020.3.2
Excellent β-stereoselectivity for the glycosylation with glucosyl donors equipped with the 3-O-picoloyl (Pico) group, without the use of participating group, was achieved in the presence of NIS/excess TfOH promoter system. A complete investigation of the scope of this reaction was performed, revealing all important attributes of successful glycosylation. While altering the halogen source was tolerated
Effect of Remote Picolinyl and Picoloyl Substituents on the Stereoselectivity of Chemical Glycosylation
作者:Jagodige P. Yasomanee、Alexei V. Demchenko
DOI:10.1021/ja307355n
日期:2012.12.12
O-Picolinyl and O-picoloyl groups at remote positions (C-3, C-4, and C-6) can mediate glycosylation reactions by providing high or even complete facial selectivity for the attack of the glycosyl acceptor. The set of data presented herein offers a strong evidence of the intermolecular H-bond tethering between the glycosyl donor and glycosyl acceptor counterparts while providing a practical new methodology for the synthesis of either 1,2-cis or 1,2-trans linkages. Challenging glycosidic linkages including alpha-gluco, beta-manno, and beta-rhamno have seen obtained with high or complete stereocontrol.