Search results for " Catalysis"

Copper(II)-dipicolinate-mediated clickable azide–alkyne cycloaddition in water as solvent

2018

Copper(II)-dipicolinate complex [CuIIL(H2O)2] (1) (H2L = dipicolinic acid (H2dipic)) was synthesized via oxidation of copper(I) iodide and pyridine-2,6-dicarboxylic acid in water and acetonitrile in the presence of glycine. Complex 1 was characterized by FT-IR and elemental analysis and its structure confirmed by single crystal X-ray analysis. This complex is an efficient precatalyst that mediates azide-alkyne cycloaddition reactions in water at room temperature either in the absence or presence of a reducing agent. Compound 1-mediated azide-alkyne cycloaddition affords alkyl/aryl substituted 1,2,3-triazole heterocycles in a regioselective manner and excellent yields under very mild reactio…

Synthesis of Polycyclic Indolines by Utilizing a Reduction/Cyclization Cascade Reaction

2021

European journal of organic chemistry 2021(45), 6097-6101 (2021). doi:10.1002/ejoc.202101191

Merging Visible-Light-Photoredox and Nickel Catalysis

2015

A new combination: The merging of visible‐light‐photoredox catalysis and nickel catalysis has been successfully achieved for cross‐coupling reactions. The synthetic scope and limitations of the combination of nickel and photoredox catalysis for Csp3-Csp2 cross‐coupling reactions is discussed.

Synthèse de mono et diphosphines dérivées d'amino acides ou de peptides, appliquées en chimie de coordination et pour le greffage de fullerène C60

2013

The synthesis of secondary phosphine borane amino acids or dipeptides and their applications for the preparation of chiral ligands or for the grafting of fullerene, is described. These compounds were synthesized in good yield (up to 98%) without racemization. The principle of the synthesis is based on the alkylation of primary phosphine borane with a γ-iodo amino acid using phase transfer conditions. Tertiary diphosphine amino acids are obtained with 70% yield after a second alkylation. These compounds are one of the first examples of diphosphine grafted with a P-C bond on the side chain of amino acid. First of all, mono and diphosphine amino acid derivatives were used in asymmetric allylic…

Computational Studies of Materials for Energy Technology: CO2 Methanation, and Halloysite Carbon-Coating

2022

The models and theories of quantum chemistry are applied in order to study two kinds of materials of interest in the field of energy technology, to understand their behavior and to verify their suitability for possible application. In particular, the effect of single Ru/Fe atom deposition on the CO2 methanation reaction occurring on the Ni(111) surface, and the effect on the band gap produced by carbon atom deposition and carbon cluster accretion on the silicic surface of halloysite, have been investigated by means of the periodic and molecular flavours of density functional theory. In order to accomplish the investigations above two entirely new computer codes were written and are actually…

Design of novel imidazolium based nanostructures for sustainable catalytic applications

2019

New examples of specific base catalysis in mononuclear rearrangements of heterocycles found via a designed modification of the side chain structure

2009

To select suitable candidates for the occurrence of specific-base-catalysis in MRH of (Z)-hydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole we have designed a modification of the side-chain structure by linking a strong electron-withdrawing system to the hydrazono group. Thus we have synthesized the (Z)-semicarbazone (3d), the (Z)-phenylsemicarbazone (3e), and the (Z)-acetylhydrazone (3f) of the above oxadiazole and examined their kinetic behavior in dioxane/water in a large range of proton concentrations (pS + 4.0 14.5). In all the pS+ range examined only a base-catalyzed process has been evidenced (no uncatalysed path occurs). The behavior at the largest pS+ values (the reactivity tends t…

Toward More Efficient Organocatalysts

2011

Functionalised Imidazolium Dicationic Ionic Liquids used as reaction media for base catalyzed organic reactions

Keggin and Wells-Dawson supported heteropolyacids as heterogeneous (photo)catalysts for gas-solid 2-propanol dehydration

2016

Catalytic and photocatalytic tests for 2-propanol dehydration to propene were successfully carried out by using binary materials obtained by supporting a Keggin or Wells-Dawson heteropolyacids via impregnation method to commercial SiO2 or TiO2. (Photo)catalytic 2-propanol dehydration was studied in gas-solid regime by using a continuous (photo)reactor working at atmospheric pressure and 80 °C. Propene and diisopropyl ether were the main reaction products. For the continuous photo-assisted runs the reactor was also illuminated with UV light. The heteropolyacid species played a key role both for the catalytic and the photo-assisted catalytic reactions; indicating that the acidity of the clust…