31410-01-2Relevant articles and documents
On the effects of head-group volume on the adsorption and aggregation of 1-(n-hexadecyl)-3-Cm-imidazolium bromide and chloride surfactants in aqueous solutions
Keppeler, Nicolas,Galgano, Paula D.,da Silva Santos, Soraya,Malek, Naved I.,El Seoud, Omar A.
, (2021/02/09)
The effects of the length of alkyl side chain (Cm) of ionic liquid-based surfactants (ILBSs) on their adsorption at the water/air interface, and aggregation in aqueous solutions were investigated for the series 1-(n-hexadecyl)-3-Cm-imidazolium bromides and chlorides, where Cm = C1-C4 for the bromides, and C1-C5 for the chlorides. These physicochemical properties were calculated from surface tension, conductivity, and fluorescence data. It was found that increasing the length of Cm (i.e., volume of the head group) leads to enhancement of surface activity, increase in the area per surfactant molecule at the water/air interface (Amin) and the degree of counter-ion dissociation (αmic). Our data also indicated that increasing the volume of the head group results in a decrease of the critical micelle concentration (cmc), Gibb's free energy of adsorption and micellization, and microscopic polarity of interfacial water. In order to delineate the effects of the presence of unsaturation in the HG, we included members that carry Cm = vinyl and allyl in the bromide series. The effect of these groups was found to be similar to removing a methylene group from Cm. The dependence of the solubilization of a lipophilic dye (Sudan IV) and a drug (nitrendipine) on the length of Cm was also studied.
Synthesis, crystal analysis and DFT calculations of Ni(II) and Pd(II) complexes of 3,3'-((1,2-phenylenebis(azanediyl))bis(2-oxoethane-2,1-diyl))bis(1-allyl-1H-imidazole-3-ium)
Al-Azmi, Amal
, p. 179 - 187 (2018/12/11)
Ni(II) and Pd(II) Complexes of 3,3'-((1,2-phenylenebis(azanediyl))bis(2-oxoethane-2,1-diyl))bis(1-allyl-1H-imidazole-3-ium) were synthesised in good yield and characterized by spectroscopic and X-ray diffraction techniques. These novel complexes, which are neutral in charge, possess square planar geometry where the coordination of the tetradentate ligand is through C2 of the imidazole moiety. These complexes are identified to be single cis-isomers as confirmed by 1H NMR and single crystal X-ray diffraction data. DFT/B3LYP calculations were also conducted using the theoretical model of the precursor heterocyclic ligand and Ni(II) and Pd(II) metal complexes. The results of these theoretical data which are calculated to be the structural parameters of optimized structures exhibited good agreement with those obtained from X-ray crystal diffraction analysis. Both metal complexes are subjected to further theoretical studies such as determination of the HOMO-LUMO gap, molecular electrostatic potential (MEP) and calculation of reactivity descriptors and the obtained results attest the superiority of these compounds as novel heterocyclic functional materials.
Palladium-Catalyzed Dehydrative Cross-Coupling of Allylic Alcohols and N-Heterocycles Promoted by a Bicyclic Bridgehead Phosphoramidite Ligand and an Acid Additive
Kang, Kyungjun,Kim, Jaewook,Lee, Ansoo,Kim, Woo Youn,Kim, Hyunwoo
supporting information, p. 616 - 619 (2016/02/18)
A mild and efficient dehydrative cross-coupling reaction between allylic alcohols and N-heterocycles using palladium catalysis is reported. A bicyclic bridgehead phosphoramidite (briphos) ligand together with Pd(dba)2 is a highly efficient catalyst, and an acid additive involved in the rate-determining step promotes the catalytic cycle. The coupling reaction of allylic alcohols with N-heterocycles including imidazoles, benzimidazoles, and triazole proceeds under mild reaction conditions with high yields using Pd/briphos and pentafluorophenol.
Synthesis, Characterization, Crystal Structures, and Catalytic C-C Coupling and Hydrosilylation Reactions of Palladium(II) Complexes Derived from CNC Pincer-Type N-Heterocyclic Carbenes
Haque, Rosenani A.,Asekunowo, Patrick O.,Budagumpi, Srinivasa,Shao, Linjun
, p. 3169 - 3181 (2015/07/15)
A series of pyridine linker containing bis(benz)imidazolium salts serving as precursors to CNC pincer-type N-heterocyclic carbene (NHC) ligands were prepared by successive N-alkylation of the azole core. Binuclear NHC complexes of silver(I) were synthesized by in situ deprotonation of the corresponding (benz)imidazolium salt with silver(I) oxide in acetonitrile at elevated temperature in the dark. Subsequently, pincer-type palladium(II)-NHC complexes were prepared by transmetalation using silver(I)-NHC complexes in acetonitrile at elevated temperatures. All compounds were fully characterized by elemental analysis, FTIR spectroscopy, and 1H and 13C NMR spectroscopy. X-ray diffraction studies on single crystals of three compounds confirmed the distorted square-planar geometry around the palladium(II) center. All complexes are monomeric in nature, and the bis-NHC ligand chelates in the CNC mode. The effective catalytic potentials of the palladium complexes were demonstrated by their high activities in aqueous-phase Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions of phenylboronic acid and n-butyl acrylate with a range of functionalized bromobenzene derivatives. The former coupling reaction afforded biphenyls in yields of 71-99%, whereas the latter reaction evidenced low yields of the n-butyl cinnamates. Further, all the palladium complexes were studied for their potential in a catalytic hydrosilylation reaction.
Design, synthesis, antiviral, and cytostatic evaluation of novel isoxazolidine analogs of homonucleotides
Lysakowska, Magdalena,Balzarini, Jan,Piotrowska, Dorota G.
, p. 341 - 353 (2014/05/20)
Moderate diastereoselectivities (d.e. 2-62%) of isoxazolidine homonucleotides were observed for cycloadditions between N-methyl-C- (diethoxyphosphoryl)nitrone and N-allyl nucleobases, with trans-isoxazolidines predominating. The stereochemistry of the substituted isoxazolidines was established based on 2D NOE experiments performed for uracil-containing cycloadducts. The cis- and trans-isoxazolidine phosphonates obtained herein were evaluated in vitro for activity against a broad range of DNA and RNA viruses. None of the compounds were endowed with antiviral activity at subtoxic concentrations, but some of them were found to inhibit the proliferation of L1210 cells with IC50 values in the range of 33-100 μM.
On the reactivity of imidazole carbamates and ureas and their use as esterification and amidation reagents
Heller, Stephen T.,Sarpong, Richmond
experimental part, p. 8851 - 8859 (2011/12/02)
The optimization, substrate scope, and mechanism of esterification and amidation of carboxylic acids mediated by imidazole-based reagents are discussed. The innate reactivity of carbonylimidazole reagents with a range of nucleophiles is also explored. New reagents developed for the synthesis of α,β-unsaturated esters are described, as are reagents for the preparation of tertiary amides directly from carboxylic acids.
METHOD OF PREPARING DIALKYLCARBONATES
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Page/Page column 11; 12, (2008/06/13)
The present invention relates to a process of preparing dialkylcarbonates, and particularly to an improved process of preparing dialkylcarbonates, which comprises performing a reaction between an alcohol compound and a chloroformate derivative in the presence of an imidazole compound, thereby enabling to prepare dialkylcarbonates with high yield in a mild condition without using toxic raw materials and to easily separate impurities.
METHOD OF PREPARING FLUORINATED ALKOXYTRIALKYLSILANES
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Page/Page column 11-12, (2008/06/13)
The present invention relates to a process for preparing alkoxytrialkylsilane, and in particular to a process, wherein an imidazole compound is added as a HCl scavenger and a reaction promoter, thereby enhancing the yield of fluorinated alkoxytrialkylsilanes and reducing corrosion problem.
MANUFACTURING METHOD OF 1-SUBSTITUTED IMIDAZOLE COMPOUND
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Page 5, (2010/02/11)
PROBLEM TO BE SOLVED: To provide a high-yield manufacturing method of a 1-substituted imidazole compound which is expected to be useful as a curing agent for epoxy resins, polyurethane resins or the like, as an intermediate of various agrochemicals, antibiotics or pharmaceuticals such as anti-AIDS agents or the like, or as dye intermediates. SOLUTION: An aldehyde compound is reacted with a primary amine to give an imine compound, and subsequently an α,β-dicarbonyl compound and ammonia are added and allowed to react with the imine compound. Preferably, the α,β-dicarbonyl compound and ammonia are simultaneously added.
Tin-free radical sequences under acidic conditions. Convergent access to azole-containing structures
Gagosz, Fabien,Zard, Samir Z.
, p. 4345 - 4348 (2007/10/03)
(equation presented) Various xanthates add efficiently to olefins bearing [1,2,4]triazole, imidazole, or benzimidazole moieties in the presence of camphorsulfonic acid via a radical chain reaction initiated by a small amount of lauroyl peroxide. The adducts may be transformed to more complex molecules by implementing a further radical cyclization.
