1,720,983 research outputs found
Naplephos and Elpanphos: pseudo-enantiomeric sugar derived ligands for asymmetric catalysis
No full text
Glucose-derived bis(pyridine-2-carboxamide) ligands (elpaN-Py) for molybdenum-catalyzed asymmetric allylic alkylations
No full textRational design of pseudo-enantiomeric libraries of ligands based on pyranoses for application in asymmetric catalysis
No full textThis review deals with the solution given by synthetic chemists to overcome the problem of access to both enantiomers of a given process when carbohydrates are used as ligands. Indeed, although sugars are stereochemically rich compounds, and derived from one of the most abundant renewable material, their use in asymmetric catalysis has been limited by the fact that most of them have D-configuration.
This review explains the concept of pseudo-enantiomeric ligands, and collects examples based on pyranoses, by describing their relevant use in asymmetric catalysis
Expanding the scope of the elpaN-type library: glucose-derived bis(pyridine-2-carboxamide) ligands (elpaN-Py) for molybdenum-catalyzed asymmetric allylic alkylations
No full textThe elpaN-Py family of ligands, which represents a subset of the elpaN-type library based on a-glucose, is described. The ligands are structural analogs of the privileged bis(pyridine-2-carboxamides) derived from trans-1,2-diaminocyclohexane, and differ for the type of substitution in the coordinating functions present in positions 1 and 2. Their ability to induce high enantioselectivity in asymmetric allylic alkylations promoted by molybdenum under microwave irradiation has been successfully demonstrated, starting from both a linear (ee up to 99%) and a branched substrate (ee up to 96%). The multifunctional nature of the sugar scaffold was exploited for the preparation of a polar ligand, through deprotection of the hydroxyl groups in positions 3, 4 and 6. In this version, it was possible to verify the performance in catalysis in alternative solvents, such as ionic liquids and water.</p
The application of pyranoside phosphite-pyridine ligands to enantioselective Ir-catalyzed hydrogenations of highly unfunctionalized olefins
No full textSimple Zn(II) Salts as Efficient Catalysts for the Homogeneous Trans-Esterification of Methyl Esters
No full textThis study aimed to optimize the zinc-catalyzed trans-esterification, and pointed to assess the effect of the solvent, the catalyst, its loading and the nature of the substrate. The screening disclosed the remarkable ability of zinc(II) acetate to promote the reaction in refluxing toluene at low catalyst loading. A significant improvement ensued with respect to recently results on the same reactions, in terms of less restrictive conditions and more convenient catalyst precursors
Hydrophilic complexes of Pd(0) with sugar-derived ligands: synthesis, characterization and use in catalysis
No full text- …
