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A strategy driven and induced by cation-π interaction was employed to obtain a magnetic porous composite material (Fe3O4/PIN) with a uniform dispersion of ferroferric oxide (Fe3O4). Utilizing ferric chloride as the catalyst, indole-based porous polymer (PIN) was successfully synthesized through the Friedel-Crafts alkylation reaction. Concurrently with the preparation of the PIN, the cation-π interaction played a pivotal role, not only driving but also inducing the effective dispersion of iron ions from the catalyst around the indole groups. Subsequently, the introduction of ferrous sulfate into the reaction mixture triggered an in-situ reaction, resulting in the uniform distribution of Fe3O4 around the indole groups within the PIN. At a temperature of 298 K, Fe3O4/PIN demonstrated remarkable adsorption efficiency for TNT, boasting a maximum adsorption capacity of 290.697 mg/g, with the ability to achieve 74% of this capacity within one hour. Moreover, Fe3O4/PIN also exhibited a commendable adsorption efficiency for TNT in real water samples. In addition, Fe3O4/PIN could be recovered rapidly due to its excellent magnetic properties. After five adsorption-desorption cycles, the adsorption capacity of Fe3O4/PIN for TNT remained at 90% of its maximum capacity. Hence, Fe3O4/PIN was anticipated to serve as an effective adsorbent for TNT. The uniform distribution of Fe3O4 in porous materials through the driving and inducing effects of cation-π is an unprecedented innovation, offering a new perspective and approach to the synthesis and utilization of similar composite materials. [ABSTRACT FROM AUTHOR]

Takemoto's catalysts were used to organocatalyze the enantioselective Friedel–Crafts reaction with different electron-rich phenols and substituted isatins. The resulting 3-aryl-3-hydroxyl-2-oxindoles were obtained in good yields (85–96%) with up to 99% ee. The substrate scope was broadened with this methodology compared to reported examples catalyzed by cinchonidine thiourea. [ABSTRACT FROM AUTHOR]

Objective: Design and synthesis of two chalcone derivatives, evaluation of their anticancer and antiinflamatory activities. Methods: The ring-closure through an intramolecular Friedel-Crafts reaction followed by an alkaline-catalyzed Claisen-Schmidt condensation. MTT assay was conducted in anticancer activity. The chalcone derivatives tested for anti-inflammatory immunomodulatory potential by measuring pro-inflammatory cytokines production levels. Results and Discussion: Both compounds displayed anti-inflammatory effects on activated mammalian cells without being cytotoxic. Their low toxicity resulted in high IC50 values in glioblastoma cells, indicating they are safe anti-inflammatory agents, yet lack anti-cancer properties. Conclusions: Synthesized and characterized two chalcone derivatives that displayed comparable anti-inflammatory effects, reducing TNF, IL6, GMCSF, and IL12p40 levels without harming macrophages. Their high IC50 values in glioblastoma cells suggest low toxicity and highlight their potential as effective anti-inflammatory agents [ABSTRACT FROM AUTHOR]

Polymeric materials make up a growing portion of urban and industrial waste that is going into landfills. Owing to the uncertainties inherent in the reuse of polymers, developing solutions for minimizing polymeric waste that are both environmentally appropriate and cost-effective has proved to be a difficult task. In this research, a polycarbonate-based hypercrosslinked polymer (HCP) adsorbent was synthesized using the knitting method by Friedel–Crafts reaction for Pb(II) ion removal. The synthesized polymer was characterized using SEM, EDS, BET, FTIR, TGA, XRD analyses. The findings showed that the synthesized HCP adsorbent could remove 98.23% of Pb (II) ions from wastewater. As for influencing factors, initial concentration, removal time, and temperature were investigated. The optimum values of initial concentration, removal time, and temperature were observed at 80 ppm, 44.48 min, and 26.03 °C, respectively. The adsorbent behavior was analyzed using isotherm and kinetic models. The result reveals that the adsorption process obeys Redlich-Peterson isotherm model, the adsorption has occurred spontaneously in the heat degree of 15–35 °C and exothermic. Moreover, the RSM model has been employed for optimizing the participant variables. According to RSM, the maximum and minimum values of adsorption capacity were 122.419 and 23.1166 mg/g, respectively, and the maximum and minimum values of adsorption percentage were 98.23 and 92.47%, respectively. [ABSTRACT FROM AUTHOR]

Firstly, the nucleophilic substitution reactions of 2,4,5,6-tetrachloropyrimidine (TCP) with hydroxybenzaldes 2a–c were employed to synthesize ((2,5,6-trichloropyrimidin-4-yl)oxy)benzaldehydes 3a–c. The fully characterization of the derived products clearly confirms that the nucleophilic attack of nucleophiles takes place at C-4 position of TCP, regioselectivity. Likewise, a clear preference for the nucleophilicity of 2a over 2b and 2c was observed in these reactions. Secondly, the solvent-less Friedel–Crafts alkylation reactions of arenes/heteroarenes with the derived aldehydes catalyzed by SiO2-H2SO4 were applied to synthesize a novel series of triarylmethane derivatives containing a trichloropyrimidine moiety. The chemical structures of all the compounds were elucidated by FT-IR, NMR spectra and elemental analyses. [ABSTRACT FROM AUTHOR]

Chiral chloro-indeno pybox has served as a new ligand for the Yb(OTf)3-catalyzed asymmetric Friedel–Crafts alkylation reaction of indoles with nitroalkenes. The tunable nature of pybox ligands enables the rational design of catalysts for optimal performance in terms of both activity and stereoselectivity in a Friedel–Crafts-type reaction. Good to excellent yields and enantioselectivities were obtained for a relatively wide range of substrates, including sterically hindered compounds, under optimized reaction conditions. [ABSTRACT FROM AUTHOR]

The reaction of 4,5-dichlorocyclopent-4-en-1,3-dione with 1,3,5-trimethoxybenzene under Friedel–Crafts reaction conditions gave, along with the expected 5-(2,4,6-trimethoxyphenyl)-4-chlorocyclopent-4-ene-1,3-dione, a disubstituted product―3,4-bis-(2,4,6-trimethoxyphenyl)-2-chlorocyclopent-2-en-1-one. [ABSTRACT FROM AUTHOR]

Friedel–Crafts alkylation was employed for the preparation of benzyl chlorine-free branched poly(4-acetoxystyrene) (PSTO). Firstly, the cationic polymerization of 4-acetoxystyrene (STO) was conducted in CH2Cl2 at − 15 °C with 1-phenylethyl chloride (St–Cl)/SnCl4/nBu4NBr initiating system. Then, the chlorine end-groups would further slowly undergo alkylation reactions (mainly intra-molecular) at 0 or − 15 °C. The Friedel–Crafts alkylation can be accelerated by elevating the reaction temperature to 25 °C, which finally led to a complete conversion of terminal benzyl chlorine groups. 1H NMR and Triple-detection GPC equipped with multi-angle laser light scattering detector (MALLS), a viscosity detector (VIS), and a refractive index detector (RI) revealed the occurrence of inter-molecular alkylation at 25 °C, which resulted in the formation of branch topology. Because of the advantages of chlorine-free and branched structures, the product is expected to be applied as photoresists to meet the requirements for high pattern resolution requirement. The benzyl chlorine-free branched poly(4-acetoxystyrene) (PSTO) was synthesized after full monomer consumption at higher temperature through Friedel–Crafts alkylation between living chain ends and benzene rings of the PSTO backbones. [ABSTRACT FROM AUTHOR]

In the past few years, graphene-based nanocomposites are a hot topic in the fields of materials and chemistry owing to their unique features. We describe a facile melt blending method for preparing polypropylene/graphene nanocomposites in this article. The first stage involved grafting graphene onto chlorinated PP using the Friedel–Crafts reaction. The second stage involved the use of the resulting PP grafted graphene (PPG) as fillers in a melt blend with commercial PP. After being grafted with an organic PP chain, graphene becomes lipophilic; consequently, the PPG can be dispersed well within the PP matrix while retaining excellent interface adhesion. As a result, the thermostability, mechanical performance, and electrical conductivity of PP were significantly improved through the addition of PPG fillers. Additionally, with 10 wt% of PPG fillers (equivalent to 5 wt% graphene sheets), the conductivity approaches 6.8 S m−1. As a result of this research, a new method for producing high-performance PP has been developed. [ABSTRACT FROM AUTHOR]

The Lewis acidic nature of both {[Zn4(µ3-OH)2(d-2,4-cbs)2(H2O)4].5H2O}n(Zn-CBS) and its ZnO nanostructures (ZnO_1, 3D microflower; ZnO_2, 3D polyhedron; and ZnO_3, 1D nanorod) was explored for the comparative study of the C–C and C-N bond forming reactions, such as Knoevenagel condensation, Friedel–Crafts alkylation and Strecker reaction, with various substrates. Notably, the nanorod (ZnO_3) is found to be an exceptionally efficient heterogeneous catalyst in comparison to its parent Zn-CBS for the Knoevenagel condensation reaction showing 100% conversion in 15 min with only 2 mol% catalyst in methanol at 25 °C. Similar catalytic results were obtained in the multicomponent Strecker reaction where ZnO_3 showed an enhanced catalytic activity in water as compared to Zn-CBS. However, for the Friedel–Crafts alkylation reaction, Zn-CBS was better than ZnO_3. These highly efficient catalysts are recyclable for three consecutive runs without any notable change in the catalytic activity. Their mechanism of action for all three reactions is also explained. [ABSTRACT FROM AUTHOR]

The heterogeneous antioxidant, namely, PS-2, 6-DTBP, was easily synthesized from chloromethylated polystyrene (CMPS) with 2, 6-di-tert-butylphenol by a simple one-step Friedel–Crafts reaction. As compared with CMPS (78 m2/g and 34.8 nm, respectively), the Brunauer–Emmett–Teller (BET) surface area (SBET) of PS-2, 6-DTBP was greatly increased to 623 m2/g, while the average pore size was sharply reduced to 7.0 nm. The antioxidative property of PS-2, 6-DTBP was extensively evaluated by the scavenging activity of superoxide and 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH·) in inhibiting oxidation of benzaldehyde, and the results indicated that 2,6-di-tert-butylphenol loaded on PS-2, 6-DTBP had excellent capability in scavenging O2−· and DPPH·, and effectively inhibited the oxidation of benzaldehyde. As a heterogeneous antioxidant with free radical scavenger, PS-2, 6-DTBP can be conveniently separated from the liquid phase and is environment friendly, showing promising potential in solid antioxidant field. [ABSTRACT FROM AUTHOR]

A series of 1,4,2-oxazaphosphorinanes was synthesized by the three-component reaction of chiral pyridylcontaining imines with trialkyl phosphites and monochloroacetic acid, followed by dealkylation of the P(O)OAlk-fragments of intermediates. It was established that the major diastereomers of the obtained heterocycles have the same configuration at both chiral centers. The synthesized 1,4,2-oxazaphosphorinanes show catalytic activity in the Friedel–Crafts reaction. [ABSTRACT FROM AUTHOR]

Mesoporous poly-divinylbenzenes prepared using very high dilution of monomers with porogenic solvent offer high surface area within relatively large pores. Their expanded morphology does not depend on nature of surrounding solvent, but during drying, it is prone to partial collapse due to the effect of capillary forces. This collapse is possible to diminish by post-polymerization crosslinking (hypercrosslinking) by Friedel–Crafts catalyzed reaction of residual vinyl groups remaining in the polymer after radical in their solvent-expanded state was evaluated using inverse steric exclusion chromatography polymerization. Effects of this hypercrosslinking were studied using two polymers prepared with monomer—porogenic solvent ratios 1:5 and 1:10. Morphologies of the examined polymers were examibed in their solvent-expanded state by inverse steric exclusion chromatography (ISEC) and in dry state by conventional nitrogen porosimetry. Evaluation of the dried hypercrosslinked polymers using conventional nitrogen porosimetry showing extremely high 70% porosity confirmed results of the swollen-state morphology assessment by the ISEC measurements. [ABSTRACT FROM AUTHOR]

A reaction intermediate is a key molecular entity that has been used in explaining how starting materials converts into the final products in the reaction, and it is usually unstable, highly reactive, and short-lived. Extensive efforts have been devoted in identifying and characterizing such species via advanced physico-chemical analytical techniques. As an appealing alternative, trapping experiments are powerful tools in this field. This trapping strategy opens an opportunity to discover multicomponent reactions. In this work, we report various highly diastereoselective and enantioselective four-component reactions (containing alcohols, diazoesters, enamines/indoles and aldehydes) which involve the coupling of in situ generated intermediates (iminium and enol). The reaction conditions presented herein to produce over 100 examples of four-component reaction products proceed under mild reaction conditions and show high functional group tolerance to a broad range of substrates. Based on experimental and computational analyses, a plausible mechanism of this multicomponent reaction is proposed. The interception of one chemical intermediate with another intermediate is very challenging, as intermediates may be incompatible or too reactive, but could result in a streamlined method of organic synthesis. Here, the authors demonstrate enantioselective four-component reactions via the coupling of two intermediates. [ABSTRACT FROM AUTHOR]

Two tetraphenylethylene-based fluorescent conjugated microporous polymers (TTTPT and TTDAT) were obtained by the Friedel−Crafts polymerization reactions catalysed by CH3SO3H. In virtue of containing tetraphenylethylene, triphenylamine and s-triazine units in their porous skeletons, the resulting TTTPT and TTDAT show excellent fluorescence sensing performance for trinitrophenol (TNP) with high quenching coefficients of 1.66 × 104 and 1.31 × 105 l mol–1, respectively. TTDAT can also sense to dinitrophenol (DNP) with the Ksv of 2.70 × 104 l mol–1. The fluorescent quenching mechanisms of TTTPT and TTDAT for selective detecting TNP attribute to conventional photoinduced electron-transfer mechanism, absorption competition quenching mechanism and/or the resonant energy transfer mechanism. [ABSTRACT FROM AUTHOR]

Natural products are well established as an important resource and play an important role in drug discovery. Here, two pyrrolinone-fused benzoazepine alkaloids, (+)-asperazepanones A (1) and B (2) with a 6/7/5 ring system, together with the artifact (−)-asperazepanone A (1), were isolated from the coral-derived Aspergillus candidus fungus. Their structures including absolute configurations were elucidated by extensive spectroscopic methods, single crystal X-ray diffraction, and ECD calculations. Furthermore, total syntheses of (±)-1 and (±)-2 have been achieved starting from the commercially L-aspartic acid diethyl ester hydrochloride and monoethyl malonate in 7 and 8 steps, respectively. The key step in the syntheses was an intramolecular Friedel-Crafts reaction to build the unique tricyclic skeleton. Interestingly, (+)-2 not only showed obviously inhibitory activity against NO production, but also inhibited potent LPS-induced expression of TNF-α and IL-6 at the concentration of 0.1 μM. It thus represents a potentially promising lead for anti-inflammatory drug discovery. Benzoazepine is a well-known pharmacophore presented in several marketed drugs. Here, the authors report the isolation and total syntheses of asperazepanones A and B from coral-derived Aspergillus candidus, two novel pyrrolinone-fused benzoazepine alkaloids with potent anti-inflammatory activities. [ABSTRACT FROM AUTHOR]

The review considers works published over the past 5 years on the synthesis, modifications, and application of chiral catalysts based on squaramides in organic synthesis. The data are grouped by types of reactions catalyzed by squaramide organocatalysts: Michael, Mannich, Pictet–Spengler, Friedel–Crafts, Henry reactions, aldol condensation, cycloaddition. For each reaction, a mechanism is considered that demonstrates the catalytic effect of squaramide organocatalysts. [ABSTRACT FROM AUTHOR]

Microporous organic polymers with high surface area are widely used in many applications. Among them, hypercrosslinked polymers have been extensively concerned because of their simple processes and low-cost reagents. However, due to most state-of-the-art strategies for HCPs based on condensation reactions, the release of small molecules such as hydrochloric acid and methanol involved in such strategies brings about new hazards to environment. Herein, we propose a method of fabrication of hypercrosslinked polymers via self-addition polymerization of divinyl benzene and its crosslinking with polar aromatic molecules. The hypercrosslinked polyDVB-based products are demonstrated by Friedel-Crafts addition reaction of double bonds on DVB that can connect adjacent phenyl rings of aromatic molecules to form the crosslinked networks. The HCPDVB-CB obtained in 1-chlorobutane as solvent has a high micropore content and displays high surface area up to 931 m2/g. Following this finding, DVB is used as a novel external crosslinker for knitting polar aromatic molecules. When L-phenylalanine and bisphenol A are used as the aromatic units, the obtained HCP(Phe-DVB) and HCP(BPA-DVB) could reach surface area of 612 and 471 m2/g, and have hydrogen uptake of 0.62 wt% and 0.58 wt% at 77 K and 1.13 bar by comparison with HCPDVB-CB having hydrogen uptake of 0.30 wt%, respectively. [ABSTRACT FROM AUTHOR]

Three carbonyl-functional novel hypercrosslinked polymers (HCP-TPS, HCP-TPA, and HCP-TPP) were successfully fabricated through an one-step Friedel–Crafts acylation reaction by copolymerizing paraphthaloyl chloride with triphenylsilane, triphenylamine, and triphenylphosphine, respectively. The resultant HCPs contained plenty of carbonyl-functional groups. Among the series of such HCPs, HCP-TPS displayed the best adsorption capability to chlorophenols (CPs), and thus it was employed as solid-phase extraction (SPE) adsorbent for enrichment of chlorophenols from water, honey, and white peach beverage prior to determination by high-performance liquid chromatography. Under the optimal conditions, the detection limits of the method (S/N = 3) were 0.15–0.3 ng mL−1 for tap water and leak water, 2.5–6.0 ng g−1 for honey sample and 0.4–0.6 ng mL−1 for white peach beverage sample. The recoveries of CPs in the spiked water, honey samples, and white peach beverage were in the range of 89.0–108.4%, 81.4–118.2%, and 85.0–113.5%, respectively. This work provides a new strategy for constructing functionalized HCPs as efficient SPE adsorbents. In this work, three novel hypercrosslinked polymers (HCPs) were synthesized by the Friedel–Crafts alkylation reaction (paraphthaloyl chloride as the alkylating agent, triphenylsilane, triphenylamine, and triphenylphosphine as the aromatic units). Then, HCP-TPS was applied to soild-phase extraction sorbent for enrichment CPs from water, honey, and white peach beverage samples. [ABSTRACT FROM AUTHOR]

N,O-Diprotonated forms (dications) of various quinolinecarbaldehydes were theoretically studied by DFT calculations. It was found that the most reactive electrophilic dications are expected to be generated from 2- and 4-quinolinecarbaldehydes compared to the other quinolinecarbaldehydes. Experimental studies of protonation of quinoline-2(6,8)-carbaldehydes in Brønsted acids (CF3SO3H, H2SO4) by means of 1H, 13C, and 15N NMR revealed the formation of the corresponding N-protonated O-protosolvated species. Reactions of quinoline-2(6,8)-carbaldehydes with arenes in the presence of Brønsted (TfOH) and Lewis acids (AlX3, X = Cl, Br) or acidic zeolites led to the formation of the corresponding 2(6,8)-(diarylmethyl)quinolines. However, 6- and 8-quinolinecarbaldehydes gave additionally unusual products – 6(8)-(arylmethyl)quinolines. [ABSTRACT FROM AUTHOR]

Six promising biologically active polymers based on a 4-tert-butylcyclohexanone moiety have been synthesized through the Friedel–Crafts reaction as new polyketone derivatives. The polymerization occurred by the interaction of three different arylidene-based monomers, with adipoyl and sebacoyl diacid chlorides. The role of such arylidene linkages on the overall performance of these new polyketones was investigated with a special attention to its antimicrobial enhancement probability. The resulting polyketones were characterized by common characterization techniques including solubility, FTIR, X-ray diffraction, and morphological properties. The thermal properties of all the resulting polyketones were evaluated using TGA and associated with their structural units. The PDTmax results indicated that all the polymers had almost similar PDTmax patterns, which appeared in the range from 440 to 630 °C. The biological activity of all the synthesized polyketones was examined and showed that most of the synthesized polyketones had antibacterial activity against microbial strains. The role of the arylidene linkage on the antimicrobial enhancement of these new polyketone derivatives was also evaluated. The tested polyketones showed significant activity against most microbial strains, and the maximum activity was observed against E. coli and P. Aeruginosa. Polymer 5b showed the maximum inhibition zone of 13 mm amongst the other polymers. Furthermore, the tested polyketones showed no significant activity against B. subtilis or the fungus C. albicans. Furthermore, molecular docking studies were applied to all polymers with the "5FSA" protein, and the results have been investigated. Polymer 5b also showed the highest docking score of − 5.84 kcal/mol. Therefore, polymer 5b was classified as a promising biologically active polymer. [ABSTRACT FROM AUTHOR]

Fluorinated porous organic networks (F-PONs) have demonstrated unique properties and applications, but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free and easy handling conditions are still rarely reported. Herein, using polydivinylbenzene (PDVB) as an easily available precursor, a novel and straightforward approach was developed to afford F-PONs via a dehydrative Friedel-Crafts reaction using perfluorinated benzylic alcohols as the cross-linking agent promoted by Bransted acid (trifluoromethanesulfonic acid). The afforded material (F-PDVB) featured high fluorine content (22 at.%), large surface area (771 m2·g−1), and good chemical/thermal stability, rendering them as promising candidates for the adsorption of CO2, hydrocarbons, fluorocarbons, and chlorofluorocarbons, with weight capacities up to 520 wt.% being achieved. This simple methodology can be extended to fabricate fluorinated hyper-crosslinked polymers (F-HCPs) from rigid aromatic monomers. The progress made in this work will open new opportunities to further expand the involvement of fluorinated materials in large scale applications. [ABSTRACT FROM AUTHOR]

The consumption of acetophenone (AP) is increasing worldwide because of its applications in products such as alcohol, aldehydes, resins, esters, fragrances, and pharmaceuticals. AP is manufactured via several methods like decomposition of cumene hydroperoxide, Hock process, and Friedel–Crafts acylation reaction using homogeneous catalysts with solvent and oxidant. However, it causes several environmental problems that deteriorate the production of AP with these methods. Oxidation of ethylbenzene (EB) is one of the promising methods to synthesize AP in liquid and vapor phases reaction using heterogeneous catalysts, which plays a vital role for selective production of AP. In this review, numerous heterogeneous catalysts are discussed including transition metal nanoparticles, transition metal complexes, and metal free catalysts (carbon nanotubes) used in last 10 years for oxidation of EB. Additionally, catalyst activity along with reaction parameters and its effect, mechanisms, and kinetics study are summarized in this article. The future scope of this reaction is also highlighted. Moreover, this work identifies best catalysts for bulk production of AP with high yield to satisfy global requirement. [ABSTRACT FROM AUTHOR]

A green and solvent-free method were developed for alkylation of N,N-dialkylanilines with substituted β-nitrostyrenes using 10 mol% of choline chloride-zinc chloride deep eutectic solvent at 70 °C. The reaction was highly regioselective and only para-substituted products have been prepared. Despite the sensitivity and weak reactivity of the aniline derivatives for the Friedel–Crafts reaction in acidic media, the presented procedure was successfully carried out this transformation. The synthetic protocol was expanded for the alkylation of pyrrole and indole to produce pharmaceutically active compounds. The reduction of the nitro group of the product to amine was performed using Pd/C and hydrazine to produce amphetamine structure. [ABSTRACT FROM AUTHOR]

Poly(acrylonitrile-co-ethylene glycol dimethacrylate-co-vinylbenzyl chloride) (poly(AN-co-EGDMA-co-VBC)) was synthesized by suspension polymerization and further hypercrosslinked by Friedel-Crafts reaction to serve as a sorbent to remove the pharmaceuticals. Energy dispersive X-ray analysis showed decreased chlorine content in the polymers, confirming a successful hypercrosslinking. BET analysis revealed that the hypercrosslinked (HXL) poly(AN-co-EGDMA-co-VBC) had a specific surface area up to 363 m2 g−1 with an average particle size of 77.2–174.1 μm. Hypercrosslinking of the polymer increased the specific surface area up to 42%, even at low VBC content (10%). Pore size distribution showed that the terpolymers were mesoporous. The maximum adsorption capacity of diclofenac (DCF) and metformin (MET) determined by the Langmuir isotherm model were up to 61.0 mg g−1 and 5.1 mg g−1, respectively and the adsorption kinetic followed pseudo-second-order rate equation. The equilibrium capacity of the sorbent decreased to approximately 78% for DCF and 72% for MET after four cycles of adsorption-desorption process, exhibiting good reusability property. [ABSTRACT FROM AUTHOR]

2,2′-Bipyridine was successfully integrated into the skeleton of hypercrosslinked polymers networks (HCPs-bipy) via Friedel–Crafts reaction and Scholl coupling reaction, and PdCl2 was locked in this network polymers by coordination with pyridine motif. The preparation of HCPs-bipy has the advantages of low cost, mild conditions, easy separation and high yield. FT-IR, TGA, N2 sorption, ICP, XPS, SEM, EDX and TEM was employed to characterize the structure and composition of the heterogeneous catalysts. The result indicates that HCPs-bipy-Pd possess high specific surface areas, large microporous volume, thermal stability, and highly dispersion of palladium species. HCPs-bipy-Pd can be applied in Suzuki–Miyaura reactions and Heck reactions as robust heterogeneous catalyst to afford high yield. The reusability test demonstrates that HCPs-bipy-Pd could be recovered and reused for at least five times without losing catalytic activity. [ABSTRACT FROM AUTHOR]

1-Phenethyl-1,2,3,6-tetrahydropyridines undergo intramolecular Friedel–Crafts reaction in trifluoromethanesulfonic acid medium, resulting in the formation of azatricyclic structures. It was shown that the direction of this reaction depended on the position of the substituent relative to the multiple bond in tetrahydropyridine. The structures of the obtained compounds were confirmed by a set of spectral analysis methods. [ABSTRACT FROM AUTHOR]

Double-stranded DNA can form efficient hybrid catalysts for asymmetric catalysis upon binding of small metal complexes, which has attracted significant interest. Catalytic microenvironment and chiral transfer are still a matter of concern. Here, we introduced peptide nucleic acid (PNA) chains to design oligo-dsPNA and hybrid PNA/DNA as chiral scaffolds to catalyze Friedel–Crafts reaction. Though with the same sequence as DNA control, dsPNA and hybrid duplexes are less suited for use in asymmetric catalysis due to ligand-Cu2+ complex does not form highly active and enantioselective hybrid catalysts with PNA-containing scaffolds. CD and UV titration assays indicated that the complex bound to suitable groove and the resulting preferential conformation are the key to catalytic performance, rather than just binding affinity. The negative charge of backbone and the resulting groove size of DNA are the key to act as a more active and highly selective catalyst than PNA. [ABSTRACT FROM AUTHOR]

Two series of silsesquioxanes-based porous polymers have been synthesized via Friedel–Crafts reaction of octavinylsilsesquioxane with tetrabiphenylsilane and octabiphenylsilsesquioxane as building blocks. The synthesized hybrid porous polymers possess specific surface areas up to 1500 m2 g−1, pore size distributions with uniform micropores centered at 1.4 nm and mesopores centered at ≈ 4.0 nm, large pore volumes up to 1.30 cm3 g−1, high fluorescence intensities and good thermal stabilities. More importantly, the porosities and fluorescence emissions of these porous polymers can be tuned systematically by adjusting the geometry of node and molar ratio of reactants. They exhibit a high adsorption ability of bulky dyes (i.e., rhodamine B, Congo red, crystal violet) and heavy metal ions. For example, the equilibrium adsorption capacity for Congo red and Pb2+ achieves as high as 2230 mg g−1 and 300 mg g−1, respectively. These results suggest that these porous polymers may have potential applications in water purification. [ABSTRACT FROM AUTHOR]

Two kinds of fluorescent conjugated microporous polymers containing pyrazine moieties were prepared by the polymerization reaction of 2,5-di-triphenylamine-yl-pyrazine (DTPAPz) and N,N,N′,N′-tetrapheny-2,5-(diazyl) pyrazine (TDPz) with 2,4,6-trichloro-1,3,5-triazine (TCT) through Friedel–Crafts reaction using the methanesulfonic acid as a catalysts. Both CMPs have high thermal stability and decomposition temperature reaches above 596 and 248 °C under nitrogen atmosphere, respectively. By right of porous morphology and electron-donating nitrogen, as well as electron-rich π-conjugated structures, the adsorption performance for iodine vapor on the CMPs is very excellent, which can reach 441% and 312%. In addition, fluorescence studies showed that the two CMPs exhibited high fluorescence sensitivity to electron-deficient iodine, o-nitrophenol (o-NP), and picric acid (PA) via fluorescence quenching. [ABSTRACT FROM AUTHOR]

A ferrocenyl chalcone (OFcPV) with attractive optical and magnetic properties for its potential application in optoelectronic devices, excellent processability in solution, and thermal stability is reported. It was derived from the synthesis of ferrocenyl chalcone with different degrees of conjugation and the preliminary selection of the most attractive molecule based on its linear optical and electrochemical properties, and processability. Three ferrocene-derived compounds: a low-molecular weight molecule (3FcPV), an oligomer (OFcPV), and a polymer (PFcPV) were synthesized through Friedel–Crafts reactions and aldol condensations. The chemical structure of the compounds has been elucidated by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopies. UV–Vis and fluorescence spectroscopies were used to evaluate the optical properties of these new compounds. The frontier orbitals levels of the materials deposited as films were determined using cyclic voltammetry. The optical bandgaps for 3FcPV, OFcPV, and PFcPV were 2.8, 2.4, and 2.36 eV, respectively. These results place these materials within the organic semiconductors and evidence the influence of the degree of electronic conjugation of the molecule in the reduction of the bandgap. The results showed that the oligomer and the polymer possess similar electronic and optical properties. However, the oligomer solubility improves the processability necessary for the manufacturing photonic devices. OFcPV was characterized by Z-scan technique, and the results indicate that OFcPV is candidate to be used as an optical limiter, fast optical switch, or optical logic gates. Also, OFcPV exhibits quasi-superparamagnetic behavior resulting from the iron disposal in the structure. [ABSTRACT FROM AUTHOR]

The effect of particles of porous aromatic frameworks, synthesized by the Friedel–Crafts reaction (PAF-FC), introduced into matrix of glassy polymer poly(1-trimethylsilyl-1-propine) (PTMSP), on the stabilization of the transport characteristics of composite membranes with a thin selective layer (2.0–2.2 Μm) was studied. As a comparison, samples of composite membranes with a selective layer based on PTMSP and PTMSP filled with PAF-11 particles synthesized by the Suzuki reaction are considered. All samples of composite membranes showed a decrease in the absolute values of gas permeability for all gases over time due to relaxation of the nonequilibrium free volume of PTMSP, therewith the greatest decrease is observed during the first thousand hours since membrane creation. The stabilization of the transport characteristics of composite membranes with PTMSP/PAF-FC occurs after 5000 h since membrane creation, further the carbon dioxide performance remains at the level of 8–9 m3 m–2 h–1 atm–1 for 9200 h. Similar performance values for aged composite membranes based on PTMSP and PTMSP/PAF-11 were about 1.5 m3 m–2h–1 atm–1. [ABSTRACT FROM AUTHOR]

Friedel-Crafts acyl rearrangements in PPA of diacetylpyrenes (80–120 °C), dibenzoylpyrenes (80–200 °C), and bis(4-flurobenzoyl)pyrenes (80–120 °C) and Scholl reactions in AlCl3/NaCl of dibenzoylpyrenes (140–200 °C) have been studied. The substrates were 1-AcPY, 2-AcPY, 1,3-Ac2PY, 1,6-Ac2PY, 1,8-Ac2PY, 2,7-Ac2PY, 1-BzPY, 1,6-Bz2PY, 1,8-Bz2PY, 1-4FBzPY, 1,6-4FBz2PY, 1,8-4FBz2PY. The mixtures of pyrene, 1-AcPY, 2-AcPY, 1,3-Ac2PY, 1,6-Ac2PY, 1,8-Ac2PY, and 2,7-Ac2PY were separated by HPLC. The following reversible intermolecular isomerizations were established: 1,6-Ac2PY ⇌ 1,8-Ac2PY, 1,6-Bz2PY ⇌ 1,8-Bz2PY, and 1,6-4'FBz2PY ⇌ 1,8-4'FBz2PY, albeit not in high yields. The results substantiate Gore's 1955 proposition that "The Friedel–Crafts acylation reaction of reactive aromatic hydrocarbons is a reversible process." The isomerizations reported here differ from the few previously reported completely reversible intramolecular Friedel-Crafts acyl rearrangements. At ≥ 140 °C, in PPA and in AlCl3/NaCl, 1,6-Bz2PY and 1,8-Bz2PY underwent a highly regioselective double Scholl reaction to give pyranthrone (3) and deacylations to 1-BzPy (and pyrene), followed by mono-Scholl reactions to give 8H-dibenzo[def,qr]chrysen-8-one (1), and 11H-indeno[2,1-a]pyren-11-one (2). The formation of 3 and not the expected tribenzo[a,ghi,o]perylene-7,16-dione (4) from 1,8-Bz2PY indicates that 1,8-Bz2PY has first undergone isomerization to 1,6-Bz2PY. The present study confirms the linkage between Friedel-Crafts acyl rearrangements and the Scholl reaction. [ABSTRACT FROM AUTHOR]

Friedel–Crafts alkylation reactions constitute a very important class of reactions which are usually catalysed in the liquid phase using Lewis acids at the industrial scale. Diphenyl methane synthesised by Friedel–Crafts alkylation from benzene with benzyl chloride has been interesting in organic synthesis, perfumes and dyes. The new environmental legislation recommends a green and reusable catalyst system that is environmentally benign which leads to minimal pollution and waste generation. Chloroaluminate ionic liquids (ILs) have been used immensely as homogeneous catalyst in the organic synthetic processes. Though these ILs have multiple advantages, their synthesis process involves certain disadvantages like multiple step synthesis, viz. use of solvents and its removal after reaction, removal of precursors, solvent washing for removal of trace impurities and drying of salt/adduct. We have established a novel single-step synthesis method of chloroaluminates from tributylamine and aluminium chloride via amine–aluminium chloride adduction using suitable solvent or one of the reactants as reaction medium. The process improved the atom economy, reduced the use of volatile organic chemicals and drastically minimised the generation of wastes. Formation of chloroaluminate ILs was confirmed by FTIR, 27Al NMR and mass spectroscopy (ESI–MS), and other physicochemical properties were also determined. The chloroaluminate IL was used as catalyst for Friedel–Crafts benzylation of benzene. The performance of the ILs as catalyst showed higher catalytic activity and could be recycled twice for benzylation reaction. Reaction parameters were also optimised to achieve higher yields of diphenyl methane. Tributylamine can be easily recovered by hydrolysis of spent IL which would moderate the chemical oxygen demand in generated effluent. [ABSTRACT FROM AUTHOR]

Racemic 2-[1-(dimethylamino)ethyl]ferrocenylphosphinic acid was tested as an organocatalyst in the Michael and Friedel—Crafts reactions. The use of this zwitterion provides 78% conversion in the Michael reaction between cyclohexanone and β-nitrostyrene, and 84% conversion in the Friedel—Crafts reaction between β-nitrostyrene and indole. [ABSTRACT FROM AUTHOR]

This paper presents the thermal properties of highly crosslinked di(methacryloyloxymethyl)naphthalene–divinylbenzene (DMN–DVB) copolymeric microspheres containing polar groups in the structure and their alkyl-bonded derivatives. C8 and C18 alkyl chains were introduced into the aromatic rings of the DMN–DVB porous copolymer by means of the Friedel–Crafts reaction. As a source of C8 and C18 alkyl chains, octyl and octadecyl chlorides were used. It was necessary to check whether the introduction of alkyl chains into the structure of polymeric packing had an impact on its thermal properties. The studies were carried out by thermogravimetry coupled online with FTIR spectroscopy and differential scanning calorimetry in inert atmosphere (helium). It was stated that the modified materials showed 20 and 50% mass losses at higher temperatures than the non-modified one while 1% mass loss was observed at lower temperatures. Moreover, an analysis of volatile decomposition products was performed. [ABSTRACT FROM AUTHOR]

New derivatives of heptazine were prepared from 2,5,8-trichloroheptazine by a Friedel–Crafts reaction and Pd-catalyzed amination. New triamino-substituted heptazine derivative represents a soluble carbon nitride monomeric unit suitable for the assembly of metal–organic and covalent–organic frameworks. Aromatic substituents in heptazine ring can be displaced by an alkylamine in a pseudo-nucleophilic substitution reaction. [ABSTRACT FROM AUTHOR]

We report a new approach to fabricate novel polyimide (PI) nanocomposites using amine-functionalized graphene nanosheets (AGNS). AGNS was successfully prepared by Friedel-Crafts (F-C) reaction and nitroreduction. The PI nanocomposites with outstanding strength and high tribological performance were obtained though in situ polymerization in the presence of different contents of AGNS. The thermal stability, mechanical performance, and the tribological properties of PI/AGNS nanocomposites were significantly enhanced compared with that of pristine PI and PI/graphene nanosheets (GNS) blends, resulting from the strong covalent bonds between AGNS with PI matrix. Particularly, given that the friction coefficient and wear rate were reduced separately by 20.5% and 90.5% under dry sliding condition, the PI/AGNS nanocomposite with 0.5 wt% AGNS manifested the optative friction performance. The combined exclusive friction resistance and mechanical performance were the paramount factors which illustrate the applications of the resultant PI/AGNS nanocomposites in the wear-resistant field or another high-performance material. [ABSTRACT FROM AUTHOR]

Abstract: An ionic liquid catalyzed Friedel-Crafts alkylation reaction of substituted benzenes with CCl4 was developed. The reaction proceeded efficiently under mild conditions, gave corresponding trichloromethylarenes with diversity functional groups in moderate to good yields. The influence of Lewis acidity of ionic liquids on the conversion of the alkylation reaction has been investigated. Notably, the probable mechanism of this reaction has been proposed with the assistance of 27Al NMR spectroscopy. It was noteworthy that the predominance of [Al2Cl7]− species in EmimCl-AlCl3, N = 0.67 could be detected by 27Al NMR spectral analysis, and [AlCl4]− was generated at the beginning of reaction. Additionally, it was found that [AlCl4]− could be transformed into [Al2Cl7]− when the reaction finished. Some control experiments confirmed that the interaction between Lewis acidic species [Al2Cl7]− of the ionic liquid and CCl4 led to the change in speciation of aluminum during the alkylation reactions.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Porous aromatic frameworks of new generation, PAF-FC, were prepared by the Friedel-Crafts reaction between tetraphenylmethane and dimethoxymethane and were characterized. The material obtained has the structure similar to that of PAF-11 and exhibits high porosity (SBET = 768 m2 g−1). Introduction of 10 wt % PAF-FC allows stabilization of the gas transport characteristics of poly[1-trimethylsilyl–1-propyne] (PTMSP) in time. For example, after 500-h annealing at 100°C, the CO2 permeability coefficient of the PTMSP/PAF-FC composite decreased by 15%, whereas the ideal CO2/N2 selectivity increased from 5.6 to 6.1. The resultant gas transport characteristics appeared to be comparable to those of the previously studied porous aromatic frameworks PAF-11. It should be noted that synthesis of PAF–11 requires using expensive chemicals in large amounts, whereas PAF-FC synthesis by linking of aromatic fragments of monomeric monomers using the Friedel-Crafts reaction is much simpler and involves the use of considerably less expensive chemicals. [ABSTRACT FROM AUTHOR]

Friedel-Crafts reaction of anisole over high silica mordenite zeolite was investigated. Detailed reaction profiles were obtained using various reaction conditions. In particular, the behavior of acetic anhydride during the reaction and the effect on the hydrophilicity of the mordenite zeolite catalyst were investigated.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Abstract: As the most important method to prepare pharmaceutical and chemical intermediate aromatic ketones, Friedel-Crafts (F-C) acylation is used to seek a novel catalytic system which is imminently consistent with the concept of green chemistry. In this study, six deep eutectic solvents (DES) were synthesized for the Friedel-Crafts acylation reaction as a catalytic solvent. Among the six DES, choline chloride-zinc chloride ([ChCl][ZnCl2]2) proved to be the most competent candidate of electron-rich arenes with acylation reagent. It got the highest yield when 1.0 equivalent of [ChCl][ZnCl2]2 used with acyl halides at 70 °C. Recycled DES was reused directly without any extra process. After five cycles, the catalytic activity did not decrease significantly (80-85%). Finally, according to experimental validation, the possible mechanism of this reaction was considered.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Polystyrene, one of the classical plastic, has caused serious environmental problems due to overuse and inability to recycle effectively. Transforming it into functional carbon materials is one of the effective ways to recycle polystyrene and other waste plastics, which has drawn the attention. In this study, we have developed a facile and efficient method for the preparation of three-dimensional (3D) network structure porous carbon (PC) via the Friedel-Crafts reaction with waste polystyrene serves as carbon source. Notably, the constructed carbonyl (-CO-) cross-linking bridges between the linear polystyrenes provide the resulting hierarchical porous polystyrene with a high cross-linking density and amounts of oxygen atoms to achieve the carbonizability of cross-linking polystyrene framework. Moreover, silica particles created more porous structure for carbon material. The prepared PC showed large specific surface area and 3D porous structure and exhibited good capacitance and electrochemical stability as electrode materials for supercapacitor. [ABSTRACT FROM AUTHOR]

A series of novel silane-based hyper-cross-linked porous polymers was prepared through the Friedel-Crafts alkylation reaction of dimethyldiphenylsilane as the monomer and formaldehyde dimethyl acetal as the external cross-linker. The structures of the polymers were confirmed by FTIR and solid-state cross-polarization magic-angle spinning 13C NMR. We investigated the porous polymers with different ratios of dimethyldiphenylsilane to formaldehyde dimethyl acetal. Porous properties were determined by nitrogen, carbon dioxide and hydrogen adsorptions. The results revealed that the porous materials possessed surface areas from 742 to 1205 m2 g−1 with the increasing amount of formaldehyde dimethyl acetal. Moreover, this material exhibited high thermal stabilities, good CO2 capture, and H2 storage capacities. The material was also used as adsorbent for organic dyes in aqueous solution and showed an excellent adsorption capacity of 952 mg g−1 for Congo red dye. These results suggest that the silane-based hyper-cross-linked porous polymers are promising materials for CO2 capture, H2 storage, and water treatment. [ABSTRACT FROM AUTHOR]

The formation of C-C bonds by using CoA independent acyltransferases may have significant impact for novel methods for biotechnology. We report the identification of Pseudomonas strains with CoA-independent acyltransferase activity as well as the heterologous expression of the enzyme in E. coli. The cloning strategies and selected expression studies are discussed. The recombinant acyltransferases were characterized with regard to thermal and storage stability, pH,- and co-solvent tolerance. Moreover, the impact of bivalent metals, inhibitors, and other additives was tested. Careful selection of expression and working conditions led to obtain recombinant acyltransferase form Pseudomonas protegens with up to 11 U mL−1 activity. [ABSTRACT FROM AUTHOR]

In this work, a construction of 12-methyl[1]benzoxepino[3,4-b]quinolin-13(6H)-ones, structurally intriguing hybrid molecules consisting of fused 4-methylquinoline and 1-benzoxepin-5-one units, has been successfully achieved via a two-step procedure, involving the onepot synthesis of 2-(aryloxymethyl)-4-methylquinoline-3-carboxylic acids followed by their intramolecular Friedel-Crafts cyclization reaction. Our synthetic protocol described here could be attractive as it is simple, easy to handle and does not involve the use of expensive reagents or catalysts. [ABSTRACT FROM AUTHOR]

Direct synthesis of triarylacetamides and 9-fluorenecarboxamides has been achieved. Phenylglyoxamides upon superelectrophilic activation in trifluoromethanesulfonic acid (triflic acid, TFSA) leads to Friedel-Crafts hydroxyalkylation or one-pot tandem hydroxyalkylation-4π-electrocyclization of aromatics into triarylacetamides or 9-fluorenecarboxamides, respectively. Mechanistic investigation by DFT calculations suggests the intermediacy of diprotonated (or “protosolvated”) intermediates. [ABSTRACT FROM AUTHOR]

A series of compounds have been prepared by the Fischer indole synthesis and Friedel-Crafts reactions, using a single acid catalyst in a one-pot conversion. The reactions have worked best with pyridyl-substituted hydrazones/indoles. Chlorination and bromination products are formed in good yields and high regioselectivities. Acylation products have also been prepared by the two-stage reaction. In the case of alkylation, the expected alkyl-substituted indoles are obtained however they are accompanied by over-alkylation products. [ABSTRACT FROM AUTHOR]

Ionic liquid used in Friedel-Crafts reaction catalytic of dialkyl diphenylamine is a green environmental method. In this paper, butyl-octyl-diphenylamine (BODPA) was synthesized by the series of 1-butyl-3-methylimidazolium chloroaluminate (BMIM-AlCl3) ionic liquids catalysts. Pressure differential scanning calorimetry (PDSC) was used to test antioxidant properties of BODPA in lubricating oil. The influences of various reaction parameters such as dosage of catalysts, molar ratio of diphenylamine to chloralkane, reaction temperature, and time on the alkylation catalyzed by BMIM-AlCl3 have been studied. The molecular structure and content of alkyl diphenylamine were also characterized by FT-IR/GC-MS. [ABSTRACT FROM AUTHOR]

Microporous covalent triazine-based polymer (MCTP) particles were synthesized via a Friedel-Crafts reaction catalyzed by AlCl3, and their morphology and textural properties were confirmed by scanning electron microscopy and N2 adsorption isotherms, respectively. Electrorheological (ER) behavior of the MCTP particle-based ER fluid dispersed in silicone oil at a volume fraction of 5% was examined using a rotational rheometer to examine its viscoelastic properties such as shear stress, shear viscosity, yield stress, and dynamic moduli. Typical ER characteristics showed an increase with increased applied electric field strength following a polarization mechanism with the slope of 2 of the electric field-dependent yield stress, highlighting MCTP as a potential ER material. The dielectric spectra were also correlated with its ER effects using an LCR meter. [ABSTRACT FROM AUTHOR]