14206-56-5Relevant articles and documents
Lewis acid promoted anomerisation of alkyl O- and S-xylo-, arabino- and fucopyranosides
Doyle, Lisa M.,Meany, Fiach B.,Murphy, Paul V.
supporting information, p. 85 - 94 (2018/12/05)
Pentopyranoside and 6-deoxyhexopyranosides, such as those from D-xylose, L-arabinose and L-fucose are components of natural products, oligosaccharides or polysaccharides. Lewis acid promoted anomerisation of some of their alkyl O- and S-glycopyranosides i
Stereoselective Epimerizations of Glycosyl Thiols
Doyle, Lisa M.,O'Sullivan, Shane,Di Salvo, Claudia,McKinney, Michelle,McArdle, Patrick,Murphy, Paul V.
supporting information, p. 5802 - 5805 (2017/11/10)
Glycosyl thiols are widely used in stereoselective S-glycoside synthesis. Their epimerization from 1,2-trans to 1,2-cis thiols (e.g., equatorial to axial epimerization in thioglucopyranose) was attained using TiCl4, while SnCl4 promoted their axial-to-equatorial epimerization. The method included application for stereoselective β-d-manno- and β-l-rhamnopyranosyl thiol formation. Complex formation explains the equatorial preference when using SnCl4, whereas TiCl4 can shift the equilibrium toward the 1,2-cis thiol via 1,3-oxathiolane formation.
Metal complexation of a D -ribose-based ligand decoded by experimental and theoretical studies
Cisnetti, Federico,Marechal, Jean-Didier,Nicaise, Magali,Guillot, Regis,Desmadril, Michel,Lambert, Francois,Policar, Clotilde
scheme or table, p. 3308 - 3319 (2012/10/18)
A combination of experimental and theoretical methods have been used to elucidate the complexation properties of a new sugar-derived hexadentate ligand, namely methyl 2,3,4-tri-O-(2-picolyl)-β-D-ribopyranoside (L). The coordination bond lengths in the complexes with MnII, Co II, NiII, and ZnII show substantial deviations from ideal octahedra with deformation towards trigonal-prismatic geometries, which is indicative of a conformationally constrained ligand. The metal-cation-ligand interactions were studied for L and the acyclic analogue L' [1,2,3-tri-O-(2-picolyl)-1,2,3-propanetriol] by spectroscopic methods and isothermal calorimetric titrations for the series MnII, Co II, NiII, ZnII, and CuII. The results indicate a stabilization of the complexes obtained with L compared with L', depending on the nature of the metal. Molecular modeling studies showed that the presence of the sugar moiety strongly favors conformations compatible with metal binding, which suggests an entropic origin of the stabilization of L complexes with regards to L' complexes. Moreover, the differences in the metal chelation profiles of L and L' are related to the constraints in the sugar group in the metal-bound structures. This study shows that foreseeing the degree of preorganization of flexible ligands may drive the design of a new generation of chelating compounds. A new sugar-derived ligand, with its coordination site embedded in a pyranoside cycle in the chair conformation, has been designed. Its transition-metal complexes were characterized by experimental and complexation methods and revealed a dramatic impact of the preorganization and complementarity of the carbohydrate scaffold on the metal binding.
