Reaction Of Acyl Chlorides Research Articles

Transition‐Metal Free, One Pot Synthesis of Selenoesters via Reaction of Alkyl Selenides and Acyl Chlorides

AbstractHerein, we report a new and efficient method for the synthesis of selenoesters by a direct coupling reaction of alkyl selenides with acyl chlorides in ethanol under transition metal‐free conditions. This nucleophilic acyl substitution afforded selenoesters in good yields. Traditionally, synthesis of selenoesters involve the reaction of acyl chlorides with an organoselenium anions generated in situ through the reductive cleavage of previously prepared diselenides. Our one‐pot approach avoids the pre‐preparation of diselenides and operated in atom‐economical and environmentally friendly conditions. The synthetic utility of these selenoesters was studied using Se‐butyl benzoselenoate as substrate in a Sonogashira‐type cross‐coupling reaction.

First 24-Membered Macrocyclic 1,10-Phenanthroline-2,9-Diamides-An Efficient Switch from Acidic to Alkaline Extraction of f-Elements.

A reaction of acyl chlorides derived from 1,10-phenanthroline-2,9-dicarboxylic acids with piperazine allows the preparation of the corresponding 24-membered macrocycles in good yield. The structural and spectral properties of these new macrocyclic ligands were thoroughly investigated, revealing promising coordination properties towards f-elements (Am, Eu). It was shown that the prepared ligands can be used for selective extraction of Am(III) from alkaline-carbonate media in presence of Eu(III) with an SFAm/Eu up to 40. Their extraction efficiency is higher than calixarene-type extraction of the Am(III) and Eu(III) pair. Composition of macrocycle-metal complex with Eu(III) was investigated by luminescence and UV-vis spectroscopy. The possibility of such ligands to form complexes of L:Eu = 1:2 stoichiometry is revealed.

Synthesis and Cyclooxygenase Enzyme Inhibitory Activity of Flurbiprofen Analogues: Simple Methodology of Their Nanoemulsion Systems

AbstractMost over‐the‐counter (OTC) and prescription NSAIDs have common side effects, especially gastrointestinal problems. Flurbiprofen, is an analogue of ibuprofen, that causes side effects and discomfort. This study was to synthesize flurbiprofen analogues, determine their NSAID activity using in vitro cyclooxygenase enzyme inhibitory assays and prepare their nanoemulsions. Six new flurbiprofen derivatives were synthesized via the reaction of acyl chloride (of flurbiprofen) and β‐amino alcohol, amino acid ester (or amino dicarboxylic acid ester). The masking of the free carboxylic acid functional group of flurbiprofen lowered the acidity by nearly two‐fold. The compounds, tested for their cyclooxygenase (COX‐1 and −2) enzyme inhibitory activity, showed analogues 3 d and 3 f could be of interest due to relatively higher COX‐2 enzyme inhibition. Nanoemulsions (NEs) of flurbiprofen analogues (3 d and 3 f) were developed using high energy emulsification technique and the results showed that the optimized nanoemulsions of 3 d presented a droplet size of 225 nm, polydispersity index of 0.568, and zeta potential of +29.60 mV.

Nickel-Catalyzed Cross-Coupling of Acyl Chloride with Racemic α-Trifluoromethyl Bromide to Access Chiral α-Trifluoromethyl Ketones.

The nickel-catalyzed reductive cross-coupling reaction of acyl chloride with racemic secondary α-trifluoromethyl bromide has been developed. By this chemistry, a series of structurally interesting chiral α-CF3 carbonyl compounds could be accessed with great enantioselectivity and good functional group tolerance. The study of late-stage transformation indicated that this chemistry could be used as the robust method to prepare products that contain a bioactive motif. Furthermore, the importance of the α-trifluoromethyl group to this reaction has been illustrated by control experiments.

Application of polyvinylidene fluoride membrane with demulsification property in oil–water separation

AbstractMembrane‐based treatment for demulsification remains a significant challenge due to membrane fouling. In this work, the demulsification and membrane separation technology were combined to design polyvinylidene fluoride (PVDF) membrane with demulsification function. The hyperbranched polyethyleneimine was prepared by the acyl chloride reaction and grafted on the PVDF membrane by dopamine. The effects of different amounts of hyperbranched polyethyleneimine on PVDF membrane were studied. The modified membrane was characterized by SEM, CA, FTIR, and XPS, and then the optimum preparation conditions were selected. The separation test shows that the modified membrane can be used to separate oil‐in‐water emulsions and the separation efficiency was more than 90%, meanwhile it showed good anti‐pollution performance owing to the water‐based protective layer on the membrane surface and the steric effect of the branches. In addition, the demulsification mechanism was analyzed and it was found that the surface tension was the key point for demulsification.

Fabrication of two multifunctional phosphorus–nitrogen flame retardants toward improving the fire safety of epoxy resin

Abstract To improve the fire safety of epoxy resin (EP), two novel phosphorus–nitrogen flame retardants, which named as diphenyl allylphosphoramidate (DPCA) and N-allyl-P, P-diphenylphosphinic amide (DCA), were synthesized by acyl chloride reaction and introduced into EP for fabricating EP composites. The combustion tests showed that incorporation of 5 wt% DPCA or 5 wt% DCA into EP led to the exceptional limited oxygen index (LOI) value (27.1% or 31.6%). Besides, the peak of heat release rate of EP-5 wt% DPCA and EP-5 wt% DCA was reduced by 40.69% and 36.69%, respectively, compared to pure EP. The enhanced fire resistance of EP was ascribed to the trapping effect of fillers in the gas phase and the charring effect in the condensed phase. Furthermore, ultraviolet-visible spectra revealed that both EP-5 wt% DPCA and EP-5 wt% DCA have considerable transparency. This study is expected to broaden the application of EP in the industrial area.

Synthesis of selenol esters via the reaction of acyl chlorides with diselenides in the presence of Zn dust catalyzed by CoCl2·6H2O

A practical and efficient approach for the synthesis of selenol and thiol esters is described via the reaction of acyl chlorides with diselenides or disulfides in the presence of Zn dust catalyzed by inexpensive CoCl2·6H2O This protocol tolerates a wide range of substrates, including aromatic and aliphatic acyl chlorides, with a variety of sensitive functional groups to afford the respective products in good yields. Furthermore, the method was also extended to use anhydrides as substrates. In addition, the obtained selenol esters could be readily transformed into vinyl selenide ketones by the selenocarbonylation of terminal alkynes catalyzed by a palladium/copper system.

C(acyl)-C(sp2) and C(sp2)-C(sp2) Suzuki-Miyaura cross-coupling reactions using nitrile-functionalized NHC palladium complexes.

Application of N-heterocyclic carbene (NHC) palladium complexes has been successful for the modulation of C–C coupling reactions. For this purpose, a series of azolium salts (1a–f) including benzothiazolium, benzimidazolium, and imidazolium, bearing a CN-substituted benzyl moiety, and their (NHC)2PdBr2 (2a–c) and PEPPSI-type palladium (3b–f) complexes have been systematically prepared to catalyse acylative Suzuki–Miyaura coupling reaction of acyl chlorides with arylboronic acids to form benzophenone derivatives in the presence of potassium carbonate as a base and to catalyse the traditional Suzuki–Miyaura coupling reaction of bromobenzene with arylboronic acids to form biaryls. All the synthesized compounds were fully characterized by Fourier Transform Infrared (FTIR), and 1H and 13C NMR spectroscopies. X-ray diffraction studies on single crystals of 3c, 3e and 3f prove the square planar geometry. Scanning Electron Microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), metal mapping analyses and thermal gravimetric analysis (TGA) were performed to get further insights into the mechanism of the Suzuki–Miyaura cross coupling reactions. Mechanistic studies have revealed that the stability and coordination of the complexes by the CN group are achieved by the removal of pyridine from the complex in catalytic cycles. The presence of the CN group in the (NHC)Pd complexes significantly increased the catalytic activities for both reactions.

The facile and efficient synthesis of novel monocyclic cis-β-lactam conjugates with a 1-methyl-1H-imidazole-2-thiol nucleus

We developed a facile and efficient synthesis of novel monocyclic cis-β-lactam conjugates with a 1-methyl-1H-imidazole-2-thiol nucleus through a ketene-imine [2+2] cycloaddition reaction of acyl chloride and different Schiff bases.

Simple Synthesis of Amides via Their Acid Chlorides in Aqueous TPGS-750-M

The technology of surfactant chemistry is employed for amide bond construction via the reaction of acyl chlorides with amines in 2 wt % TPGS-750-M aqueous solution. Specifically, this highly effici...

Сationic carboxamide derivatives of tricyclic heteroaromatic compounds: synthesis and preliminary evaluation of antiproliferative activity

This research was aimed at the synthesis and study of biological activity of the carboxamides of tricyclic heteroaromatic systems, acridone, phenazine and thioxanthone, containing the aliphatic and aromatic cationic substituents at amide fragment. These heterocyclic cores are DNA intercalating agents, whereas the introduction of cationic groups provides additional ionic interactions of the ligands with their biological targets, such as DNA and enzymatic complexes of the system of nucleic acids biosynthesis. A convenient way of the introduction of such groups is a modification of heterocyclic carboxamides. A small library of new cationic amide derivatives of acridone-4-, phenazine-1- and thioxanthone-4-carboxylic acids was obtained. They were synthesized in 37-81% yield by mild and selective quaternization of the nitrogen atoms at N,N-dimethylaminoalkyl (alkyl = ethyl, propyl) and pyridylmethyl fragments of the neutral N-functionalized carboxamides with methyl iodide. Tricyclic heteroaromatic cores were not affected. Convenient protocol for the synthesis of thioxanthone-4-carboxylic acid (TCA) based on the reaction of 2-mercaptobenzoic and 2-iodobenzoic acids followed by cyclization of the intermediate was developed (yield 79%). A series of new N-functionalized neutral amides of TCA, the precursors of corresponding cationic carboxamide, were also obtained via the reaction of acyl chloride with amines. Preliminary in vitro testing of four compounds as potential antitumor agents in U87MG tumor cell culture (human malignant glioma) demonstrated their significant antiproliferative activity at low micromolar concentrations, with growth inhibition values GI50 in the range 1.7-11 µM. These results suggest that cationic carboxamides of tricyclic heteroaromatic systems are promising scaffolds for the design of new antitumor drugs.

Acyl-chloride functionalized graphene oxide chemically grafted with hindered phenol and its application in anti-degradation of polypropylene

In this study, graphene oxide (GO) nanosheets were first functionalized by the acyl-chloride reaction and then reacted with hindered phenol (HP) to obtain HP grafted GO (GO-g-HP). The GO-g-HP prepared under the optimized condition exhibited a high efficiency against both thermal and photo oxidation of isotactic polypropylene (iPP). GO-g-HP exhibited a much better anti-aging efficiency than that of HP and GO used individually or that of their physical mixture. The outstanding anti-aging effect of GO-g-HP was attributed to the excellent synergistic effect produced between the chemically bonded GO and HP, which resulted in an improved oxygen barrier property of GO and excellent utilization of the free radical scavenging capability of GO and HP. Also, thanks to the grafting of HP on GO, the physical loss of HP, which was one of the main shortcomings for traditional small molecular antioxidants, was largely suppressed. It is expected that the GO-g-HP prepared can well meet the requirement of long-term applications of polymers in some harsh service conditions.

Palladium(II) on 4 \u212b Molecular Sieves: A Simple and Reusable Catalyst for the Preparation of Ynones

Pd2+ on 4 Å molecular sieves support has been prepared and investigated. The catalyst has successfully been used in the reaction of acyl chlorides and terminal alkynes yielding ynones. The catalyst can be reused without significant loss of activity.Graphic

Synthesis and application of new S-benzoheterocycle thiobenzoates photoinitiators

A series of free radical photoinitiators with thioester bonds were synthesized by the nucleophilic substitution reaction of acyl chloride and thiol or thiophenol. These compounds could be efficiently obtained under mild reaction conditions and were fully characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry. This kind of compounds exhibited a strong ultraviolet–visible light absorption spectrum with an extended absorption around 330 nm in DMSO. Moreover, these compounds were utilized as free radical photoinitiators in ultraviolet curing and the resulting films exhibited comparable mechanical properties in comparison with commercially available photoinitiators, such as 1-hydroxycyclohexyl phenyl ketone (Irgacure 184) and benzophenone. We also proposed a probable photoinitiated polymerization mechanism for S-benzoheterocycle thiobenzoates as photoinitiators.

Metal Chelating Polymer Thin Films by Surface-Initiated ROMP and Modification

We report the surface-initiated ring-opening metathesis polymerization (SiROMP) of hydroxamic acid-containing, metal-chelating polymer thin films. SiROMP of trans-5-norbornene-2,3-dicarbonyl chloride (NBDAC) is introduced as a versatile platform to achieve many functional polymer films via simple exposure of pNBDAC films to reagents. This modification strategy owes its success to the fast and high-yield reaction of acyl chlorides with alcohols, amines, water, and other molecules. The polymerization of NBDAC is performed with monomer in the vapor phase and exhibits rapid kinetics, producing ∼400 nm thick films within 5 min. Because of the high reactivity of the acyl chloride groups in the film, the pNBDAC films are easily modified to produce side chains of carboxylic acids, esters, and amides via the reaction of the acyl group with water, alcohols, and amines, respectively. Exposure of the pNBDAC film to hydroxylamine results in a film with hydroxamic acid functionality that is capable of chelating various metal ions. The chelation process effectively cross-links the polymer chains to greatly improve the thermal and pH stability of the film in solution, elevate resistance against water and ion transfer, and alter the mechanical properties to a more solid-like film.

Amide-based covalent organic frameworks materials for efficient and recyclable removal of heavy metal lead (II)

Covalent organic frameworks (COFs) materials with designed skeleton structure and controlled pore size are a new class of adsorbent materials for environment remediation. Here, we synthesize two amide-based COFs materials via a polymerization reaction of acyl chloride and amino groups by mechanical ball milling at room temperature for Pb2+ removal as adsorbents. Two types of diamine monomers are selected to construct COFs with different framework structure and functional groups contents, i.e. COF-TP from aromatic diamine and COF-TE from linear diamine. The as-prepared COFs materials display typical lamellar structure, and the amide groups on COFs skeleton are confirmed to behave as active adsorption sites for Pb2+ capture via multi-coordination. COF-TE exhibits superior Pb2+ adsorption capacity to COF-TP, because that less aromatic skeleton and weak π-π stacking of COF-TE facilitate higher internal diffusion of Pb2+ adsorption. Meanwhile, the higher amide group content on COF-TE leads to its higher saturated adsorption capacity of 185.7 mg/g than COF-TP of 140.0 mg/g. Finally, great recycling stability of Pb2+adsorption allows the amide-based COFs materials to be promising adsorbents for heavy metal Pb2+ removal or recovery.

A Simple One‐pot Three‐component Synthesis of Dihydrobenzo[4,5]imidazo[2,1‐ b ]thiazol‐3‐ols by Reaction of Acyl Chlorides, Isocyanides, and 2‐Mercaptobenzimidazoles

A Simple One‐pot Three‐component Synthesis of Dihydrobenzo[4,5]imidazo[2,1‐ <i>b</i> ]thiazol‐3‐ols by Reaction of Acyl Chlorides, Isocyanides, and 2‐Mercaptobenzimidazoles

Effect of nano-TiO2 immobilized antioxidant on ageing resistance behavior of thermoplastic vulcanizate exposed to UV/O3

Nano-TiO2 immobilized antioxidant (TiO2-KH550-AG) was prepared to improve the ageing resistance of thermoplastic vulcanizate (TPV) exposed to UV/O3. TiO2 nanoparticles were firstly modified with 3-aminopropyltriethoxysilane (KH550) and then reacted with the antioxidant, 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid (AG), through the acyl chloride reaction followed by the amidation. FT-IR, XPS and TGA measurements confirmed that the antioxidant (AG) was chemically immobilized onto the nano-TiO2 surfaces. TPV/TiO2-KH550-AG nanocomposites were prepared by melt mixing. SEM observation showed that TiO2-KH550-AG was homogeneously dispersed into the matrix of TPV. The UV/O3 ageing test of the samples was carried out in the environment with constant UV intensity of 1.40 mW/cm2 and ozone concentration of 100 ± 4 mg/m3. The ageing resistance behavior of the TPV/TiO2-KH550-AG nanocomposites was evaluated by the changes of surface morphology, mechanical properties and carbonyl index during the UV/O3 ageing test. It was observed that the TPV/TiO2-KH550-AG exhibited high stability during the process of UV/O3 ageing. The results revealed that the anti-ageing efficiency of TiO2-KH550-AG was superior to the mixture of the corresponding AG and modified TiO2, owing to the better dispersion and migration resistance of TiO2-KH550-AG.

Concise synthesis of 3,4-dihydro-1,4-benzoxazines by three-component reactions of acyl chlorides, o-aminophenols and 1,2-dichloroethane

The Cu(OAc)2-catalyzed three-component reactions of o-aminophenols, acyl chlorides and 1,2-dichloroethane (DCE) have been established for the efficient synthesis of 3,4-dihydro-2H-benzo[b][1,4]oxazines (3,4-dihydro-1,4-benzoxazines). This method features advantages of the one-pot operation enabling N-acylation, CCl bond amidation and etherification, as well as the structural divergence of the synthesized products.

Design, synthesis and neuroprotective activities of novel cinnamide derivatives containing benzylpiperazine moiety

A new series of cinnamide derivatives 6a–l were synthesized by the reaction of acyl chlorides with various substituted benzylpiperazines. The structures were characterized by 1H NMR, 13C NMR, and HRMS. The potential neuroprotective activities of cinnamide analogs were evaluated in differentiated rat pheochromocytoma cells (PC12 cells) and in mice subjected to acute cerebral ischemia. Among the series, 6a, 6b, and 6c, featuring a 1,3-benzodioxole moiety, showed potent neuroprotection both in vivo and in vitro. The three compounds were selected and further studied to determine their mechanism of action. MTT assay, Hoechst 33342/PI double staining, and high content screening (HCS) revealed that pretreatment of the cells with 6a, 6b, and 6c has significantly decreased the extent of cell apoptosis in a dose-dependent manner. The results of western blot analysis demonstrated these compounds suppressed apoptosis of glutamate-induced PC12 cells via caspase-3 pathway. These compounds can be lead compounds for further discovery of neuroprotective agents for treating cerebral ischemic stroke.