Zn(II) Triflate-CatalyzedN-Glycosylation: Synthesis of Sulfonamide and Amide Functionalized 2,3-Unsaturated Glycosides
摘要:
GRAPHICAL ABSTRACT[GRAPHICS]A highly efficient and mild method for the synthesis of glycosyl sulfonamides and glycosyl amides from glycal has been described using Zn(OTf)(2) as an economical and environmentally friendly catalyst. Various N-nucleophiles comprising sulfonamides, benzamides, and carbamates were glycosylated with glycals to obtain corresponding 2,3-unsaturated N-glycosides in good yields.
A mild and efficient synthetic protocol for Ferrier azaglycosylation promoted by ZnCl2/Al2O3
作者:Feiqing Ding、Ronny William、Bala Kishan Gorityala、Jimei Ma、Siming Wang、Xue-Wei Liu
DOI:10.1016/j.tetlet.2010.04.045
日期:2010.6
An improved method for the Ferrier sulfonamidoglycosylation of tri-O-acetyl-D-glucal with different N-nucleophiles has been developed. ZnCl2 impregnated on activated alumina acts as an excellent reagent system for the conversion of 3,4,6-tri-O-acetyl-D-glucal into 2,3-unsaturated-N-pseudoglycals with good yields and preferential alpha-anomeric selectivity. (C) 2010 Elsevier Ltd. All rights reserved.
Ruthenium trichloride catalyzed synthesis of 2,3-unsaturated-N-glycosides via Ferrier azaglycosylation
An efficient, economical and mild protocol for the synthesis of 2,3-unsaturated-N-glycosides has been developed using ruthenium(III) chloride. The Ferrier azaglycosylation of glycals with various N-nucleophiles such as sulfonamides, benzamides, carbamates and N-substituted sulfonamides proceeded smoothly to afford the corresponding 2,3-unsaturated-N-glycosides or 'N-pseudoglycals' in good yields (64-98%). High alpha-anomeric selectivity was observed with N-substituted sulfonamides such as N-benzyl or N-phenyl sulfonamides under similar conditions. (C) 2014 Elsevier Ltd. All rights reserved.