Search results for "Reaction"

The first catalytic method for Heck alkynylation of unactivated aryl bromides (copper-free Sonogashira) in an ionic liquid: 1 mol-percent palladium/t…

2007

Herein we report the studies of Heck alkynylation (copper-free Sonogashira) with aryl halides (I, Br, Cl) employing various metallic precursors, tertiary phosphanes and bases in [BMIM][BF4] as the solvent. As a result, we provide the first method that allows the coupling of a large array of substrates, either activated or deactivated bromides in an ionic liquid. Furthermore, the system of highest efficiency is unexpectedly the simplest and cheaper combination that employs [Pd(η3-C3H5)Cl]2/PPh3 at only a 1 mol-% loading with pyrrolidine as the base and in the absence of a copper salt. The coupling of sterically and electronically deactivated bromides bearing different functional groups to ar…

An Overview on the Performance of 1,2,3-Triazole Derivatives as Corrosion Inhibitors for Metal Surfaces

2021

This review accounts for the most recent and significant research results from the literature on the design and synthesis of 1,2,3-triazole compounds and their usefulness as molecular well-defined corrosion inhibitors for steels, copper, iron, aluminum, and their alloys in several aggressive media. Of particular interest are the 1,4-disubstituted 1,2,3-triazole derivatives prepared in a regioselective manner under copper-catalyzed azide-alkyne cycloaddition (CuAAC) click reactions. They are easily and straightforwardly prepared compounds, non-toxic, environmentally friendly, and stable products to the hydrolysis under acidic conditions. Moreover, they have shown a good efficiency as corrosi…

Multiple solutions for semilinear Robin problems with superlinear reaction and no symmetries

2021

We study a semilinear Robin problem driven by the Laplacian with a parametric superlinear reaction. Using variational tools from the critical point theory with truncation and comparison techniques, critical groups and flow invariance arguments, we show the existence of seven nontrivial smooth solutions, all with sign information and ordered.

Cross-coupling reactions of organoborons with organic halides

2011

Naphthalene-2,6-diyl bis(4-methylbenzenesulfonate)

2018

The complete molecule of the title compound, C24H20O6S2, is generated by a crystallographic inversion centre at the middle of the naphthalene ring system. The dihedral angle between the naphthalene ring system and the pendant benzene ring is 10.23 (6)° and the C—S—O—C torsion angle is −172.05 (10)°. In the crystal, weak C—H...O interactions link the molecules into (10-1) sheets.

4-Chloronaphthalen-1-yl 4-methylbenzenesulfonate

2018

In the title compound, C17H13ClO3S, the naphthalene ring system and the benzene ring of the tosylate substituent are inclined to one another by 55.32 (5)°. The crystal structure features weak intermolecular C—H...O hydrogen bonds, one of which forms inversion dimers. Additional C—H...O hydrogen bonds and weak Cl...Cl halogen bonds stack the molecules along the b-axis direction.

3,5-Dimethoxyphenyl 4-methylbenzenesulfonate

2017

Molecules of the title compound, C15H16O5S, are composed of a 3,5-dimethoxyphenyl moiety substituted with a toluene-4-sulfonate group. The dihedral angle between two aromatic rings is 57.23 (4)°. In the crystal, molecules are connected by weak C—H...O hydrogen bonds and S...O van der Waals interactions.

3,5-Bis(trifluoromethyl)phenyl 4-methylbenzenesulfonate

2017

Molecules of the title compound, C15H10F6O3S, are composed of 3,5-bis(trifluoromethyl)phenyl substituted with a toluene-4-sulfonate group. The dihedral angle between two aromatic moieties is 45.10 (5)°. In the crystal, molecules are connected by weak C—H...O and C—H...F contacts. One of the trifluoromethyl groups is disordered.

Chlorido(2,2′-{[2-(1-methyl-1H-imidazol-2-yl-κN 3)imidazolidine-1,3-diyl-κN]bis(methylene)}bis(1-methyl-1H-imidazole-κN 3))copper(II) perchlorate

2019

In the crystal structure of the title complex, [CuCl(C17H24N8)]ClO4, the copper(II) metal exhibits an N4Cl pentacoordinate environment in a distorted square-pyramidal geometry. Coordination to the metal centre occurs through the three 1-methylimidazole N atoms from the pendant groups, one amine N atom from the imidazolidine moiety and one chlorido anion. Intermolecular interactions take place at two of the 1-methyl-imidazole rings in the form of parallel-displaced π–π stacking interactions forming chains parallel to the a axis. Three O atoms of the perchlorate anion are rotationally disordered between two orientations with occupancies of 0.5.

Crystal structure and Hirshfeld surface analysis of 3-octyl-4-oxo-2,6-bis(3,4,5-trimethoxyphenyl)piperidinium chloride

2018

The title compound was synthesized by a one-pot Mannich condensation reaction. In the crystal, centrosymmetric dimers are linked into layers parallel to (011) by N—H⋯Cl and C—H⋯Cl hydrogen bonds. A Hirshfeld surface analysis indicates that O—H (20.5%) inter­actions make the largest contribution to the crystal packing.