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The reaction between bis(1,2,3‐triazol‐1‐yl)methane derivatives and nBuLi and various aldehydes, yielded novel neutral ligand precursors incorporating alcohol functional groups. The resulting compounds exhibited distinct characteristics depending on the steric hindrance of the aldehyde employed. In instances where aromatic aldehydes were utilized, functionalization occurred at the methine group bridging both triazole rings. Conversely, the use of pivalic aldehyde prompted functionalization at the C5 position of the triazole ring. These compounds were subsequently employed as ligand precursors in the synthesis of organometallic aluminum and zinc complexes, yielding dinuclear complexes with high efficiency. The structural elucidation of all compounds was accomplished through spectroscopic methods and validated by X‐ray crystallography. Preliminary catalytic investigations into the coupling reaction of cyclohexene oxide and CO2 revealed that aluminum and zinc complexes catalyzed the selective formation of polyether and polycarbonate materials, respectively. [ABSTRACT FROM AUTHOR]

The potential of aerogels as catalysts for the synthesis of a relevant class of bis-heterocyclic compounds such as bis(indolyl)methanes was investigated. In particular, the studied catalyst was a nanocomposite aerogel based on nanocrystalline nickel ferrite (NiFe2O4) dispersed on amorphous porous silica aerogel obtained by two-step sol–gel synthesis followed by gel drying under supercritical conditions and calcination treatments. It was found that the NiFe2O4/SiO2 aerogel is an active catalyst for the selected reaction, enabling high conversions at room temperature, and it proved to be active for three repeated runs. The catalytic activity can be ascribed to both the textural and acidic features of the silica matrix and of the nanocrystalline ferrite. In addition, ferrite nanocrystals provide functionality for magnetic recovery of the catalyst from the crude mixture, enabling time-effective separation from the reaction environment. Evidence of the retention of species involved in the reaction into the catalyst is also pointed out, likely due to the porosity of the aerogel together with the affinity of some species towards the silica matrix. Our work contributes to the study of aerogels as catalysts for organic reactions by demonstrating their potential as well as limitations for the room-temperature synthesis of bis(indolyl)methanes. [ABSTRACT FROM AUTHOR]

A highly efficient eco-benign pathway was developed for the synthesis of a library of 34 bis(indoyl)methane derivatives using triethylammonium hydrogen sulfate ionic liquid as a green catalyst in high to excellent yields (82–98%) at room temperature. The reaction was easy to execute by simply mixing two equivalents of indole with one equivalent of different aldehydes (including aromatic, heterocyclic, and aliphatic) using ionic liquid as a catalyst and water as a solvent under stirring at mild reaction environment. The current methodology has several benefits such as operational simplicity, short time period (25–60 min), cost-efficient, environment-friendly, easily recoverable catalyst, and highly reusable up to five cycles. [ABSTRACT FROM AUTHOR]

Bis(indolyl)methanes (BIMs) are a class of compounds that have been recognized as an important core in the design of drugs with important pharmacological properties, such as promising anticancer and antiparasitic activities. Here, we explored the biological activity of the BIM core functionalized with different (hetero)aromatic moieties. We synthesized substituted BIM derivatives with triphenylamine, N,N-dimethyl-1-naphthylamine and 8-hydroxylquinolyl groups, studied their photophysical properties and evaluated their in vitro antiproliferative and antiparasitic activities. The triphenylamine BIM derivative 2a displayed an IC50 of 3.21, 3.30 and 3.93 μM against Trypanosoma brucei, Leishmania major and HT-29 cancer cell line, respectively. The selectivity index demonstrated that compound 2a was up to eight-fold more active against the parasites and HT-29 than against the healthy cell line MRC-5. Fluorescence microscopy studies with MRC-5 cells and T. brucei parasites incubated with derivative 2a indicate that the compound seems to accumulate in the cell's mitochondria and in the parasite's nucleus. In conclusion, the BIM scaffold functionalized with the triphenylamine moiety proved to be the most promising antiparasitic and anticancer agent of this series. [ABSTRACT FROM AUTHOR]

The study presents a streamlined procedure for synthesizing bis(indolyl)methane derivatives using decanoic acid as a promoting medium. The reactions involve the addition of 2‐methyl‐1H‐indole with different aromatic aldehydes at room temperature for 24 h. Decanoic acid is effective for enhancing the reactivity of aromatic aldehydes through electrophilic activation. The new synthetic method yields pure compounds without requiring workup and purification. This method avoids metal‐containing catalysts and provides a simple, cost‐effective procedure with excellent yield. It is suitable for large‐scale synthesis and eliminates the use of corrosive acids. [ABSTRACT FROM AUTHOR]

In this work, a novel Praseodymium complex of tromethamine immobilized onto the SBA-15 channels was successfully synthesized by a simple procedure. The SBA-15@Tromethamine-Pr was synthesized easily using chemical attachment of tromethamine compound on (3-Chloropropyl)trimethoxysilane (CPTMS) functionalized SBA-15 (SBA-15@n-Pr-Cl), followed by treatment with Praseodymium(III) nitrate pentahydrate salt in ethanol under reflux conditions. The proposed catalysts were characterized by FT-IR, XRD, EDX, Map, ICP-OES, SEM, and TGA studies and were successfully applied in the synthesis of for the synthesis of bis(pyrazolyl)methane derivatives. This designed protocol offers several advantages including the use of commercially available and inexpensive materials, short reaction times, high yield, simple procedure, and easily separable and reusable catalyst. [ABSTRACT FROM AUTHOR]

An efficient sequential one‐pot, two‐step pseudo‐four‐component reaction between 3/4‐methyl N‐sulfonyl ketimines with 3‐chloropropiophenones triggered by DIPEA/NaHCO3 as a cooperative base and subsequent aza‐cyclization using NH4OAc is reported. This transition‐metal‐oxidant‐free technique concocts new C−C/C=C/C=N−C bonds selectively, guaranteeing acceptable yields of 2,3,6‐trisubstituted pyridines possessing ortho‐hydroxyaryl/benzenesulfonamide and propiophenone moieties at C2 and C3 positions, respectively. Interestingly, while replacing methyl‐substituents with straight alkyl chains of N‐sulfonyl ketimines, only a monoalkylation reaction happened with in situ‐generated vinyl ketones to deliver promising yields of 3‐picoline derivatives. Moreover, the synthetic transmutation of prepared pyridine derivative led to several important classes of pyridocoumarin, 5H‐chromenopyridine, and di(pyridin‐3‐yl) methane derivatives. [ABSTRACT FROM AUTHOR]

A novel double Friedel–Crafts reaction of acylsilanes in water is described. This strategy enables synthesis of bis(indolyl)methane derivatives with 1-hydroxy or 1-silyl substituents in moderate to high yield. Compared to the 1-silyl-bis(indolyl)methane derivatives from indole substrate, 1-hydroxy-bis(indolyl)methane derivatives were synthesized from the 5-hydroxyindole, and the hydrogen bonds in the 5-hydroxyindole play a crucial role in regulating the reaction selectivity. [ABSTRACT FROM AUTHOR]

A convenient, eco-friendly electrophilic reaction of indole with substituted aromatic aldehydes to yield bis(indolyl)methane (BIM) derivatives. BIM derivatives are synthesized in one pot by employing a biopolymer-derived novel heterogeneous catalyst, Xanthan Perchloric Acid (XPA). The Catalyst XPA is prepared from biopolymer xanthan and treated with perchloric acid. XPA is thermally stable with sufficient acidic sites, mild, nontoxic, and reusable. The reaction proceeds smoothly at room temperature in the green context, shorter reaction time, and excellent yield under solvent-free conditions. [ABSTRACT FROM AUTHOR]

A novel catalytic system of a nickel(II) complex of (E)-N′-((2-amino-5-chlorophenyl)(phenyl)methylene)-2-hydroxy-benzohydrazide (APH) supported on graphene oxide (GO) has been prepared. Detailed characterization of the synthesized catalyst has been carried out using NMR, FTIR, HRMS, PXRD, Raman, SEM, TEM, EDX and XPS. Its catalytic efficiency has been explored for the synthesis of various bis(indolyl)methane derivatives. The optimized reaction conditions prove that the catalyst is highly efficient, performs under mild conditions and is required in a very small amount (2 wt%). A diversified library of bis(indolyl)methane derivatives containing various electron donating and withdrawing substituents has been developed in high to excellent yields. The catalyst is equally efficient towards heterocyclic aldehydes. Moreover, owing to the strong covalent interaction between the APH–Ni(II) complex and GO, the catalyst shows outstanding recyclability for six subsequent cycles without any significant loss in activity. [ABSTRACT FROM AUTHOR]

The metal-free feature of mechanosynthesis of bis(3-indolyl)methane derivatives using poly(4-vinyl pyridine), a commercially available functional polymer, by ball mill technique at ambient conditions was studied. The condensation of various carbonyl compounds with two indoles smoothly proceeded, and pure products were easily isolated in high to excellent yields. Poly(4-vinylpyridine) exhibited high recyclability without any loss of catalytic activity or change in the chemical structure. The influence of polymer M̅W with a certain PDI on the mechanosynthesis of BIMs was investigated. In addition, the effect of the ball and jar with zirconium oxide material was studied on the rate and yield of the BIMs synthesis process. The method was scalable and generated minimal hazardous wastes. Some merits of the current methodology are such as the good to high yields for various carbonyl compounds and avoiding the use of toxic, expensive, and metal-containing catalysts with a tedious process of preparation, separation, and purification. [ABSTRACT FROM AUTHOR]

Bis(indolyl)methane derivatives are efficiently synthesized from indole/2-methyl indole and aldehydes using acidic ionic liquid immobilized on magnetic Fe3O4 nanoparticles. Catalyst used in this methodology is synthesized and characterized using various techniques like FT-IR, TGA, TEM, EDX, Powdered XRD and VSM. The catalyst can be easily retrieved by an external magnet and has been reused up to five runs without any appreciable loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

An efficient one pot synthesis of various bis-coumarinyl methane derivatives was investigated by condensing a series of aldehydes with 4-hydroxy coumarin in the presence of Amberlyst 15 catalyst under refluxing conditions in ethanol–water (1:1). This one pot domino Knoevenagel condensation/Micheal addition reaction provides excellent yield of bis-coumarinyl methane derivatives with lots of advantages like shorter reaction time, eco-friendly reaction medium, simple work up, recyclability of the catalyst and chromatography-free purification. Moreover, the synthesized compound was exploited to develop bis-coumarinyl methylene-based nanostructured materials of special interests which were investigated by UV–Vis, fluorescence spectroscopy, imaging in scanning electron microscope and atomic force microscope. Our UV–Vis and fluorescence study indicated that some of the organic compounds are organized as H-aggregate in the thin film. We also investigated I–V characteristics of the thin film of some of the selective compounds which showed write-once-read-more memory switching behaviour onto the thin film under investigations. [ABSTRACT FROM AUTHOR]

Seven arylbis(indolyl)methanes were synthesized by electrophilic substitution reaction of aromatic aldehydes on indole using glacial acetic acid as catalyst in aqueous media under ultrasonic irradiation. The synthesized bis-indole derivatives were characterized using elemental analysis, 1H and 13C NMR, FT-IR spectroscopy, and mass spectrometry and were screened for their nematicidal activity against the root knot nematode Meloidogyne incognita. The efficiency of the synthesized compounds was evaluated in vitro by egg hatching and mortality tests. All tested compounds showed significant nematicidal potential, and the nitro substituted derivative, 3,3′-[(4-nitrophenyl)methylene]di(1H-indole), exhibited the highest activity. [ABSTRACT FROM AUTHOR]

An efficient and green protocol has been introduced for the synthesis of medicinally important bis(indolyl)methane derivatives using pyruvic acid catalyst in the presence of water. Pyruvic acid catalyzes the reaction of aldehyde with indole efficiently and products were obtained in good to excellent yields under sonication (50 °C) or under conventional heating (80 °C). The advantages of this synthetic methodology are use of environmental-friendly, commercially available, biodegradable catalyst, short reaction times, Lewis acid-free and metal-free mild reaction conditions with excellent yields and is compatible with a wide range of electronically diverse substrates. Pyruvic acid in water as a catalyst under ultrasound radiation can be a better alternative to synthesize bis(indolyl)methane derivatives than some of the traditional methods. [ABSTRACT FROM AUTHOR]

The synthesis of bis(indolyl)methane derivatives in the reaction between indoles and aldehydes was carried out in a short reaction time (10-20 minutes) with good yield (78-96%) by using 1 mol% of nanoγ-Al2O3 in H2O as a green solvent at room temperature. Moreover, we usednanoγ-Al2O3 as an effortlessly accessible, less costly, and possible under eco-friendly conditions catalyst in this method. Consequently, this method presented significant benefits containing a low amount of the catalyst, purification of target molecules by non-chromatographic process, use of recyclability of the catalyst, simply efficient, green, and suitable for the synthesis of a broad range of bis(indolyl)methane derivatives. This method achieves to have a numerous scope concerning the difference in the aldehydes and indoles. Moreover, water was the only by-product, which added to its attractiveness. Bis(indolyl)methane derivatives have a varied range of bioactive metabolites of native and marine sources. The hydrothermal and chemical stability of γ-Al2O3 is a severe point for catalytic applications. The melting point, FT-IR, and ¹H NMR spectra of the selected product showed that these products were synthesized successfully. [ABSTRACT FROM AUTHOR]

The reaction of pentachloropyridine with indoles and bis(indolyl)methanes (BIMs) were investigated. Indoles in basic medium exclusively react with pentachloropyridine to give the corresponding N-perhalopyridine substituted indoles. Furthermore, BIMs in reaction with pentachloropyridine gave N-perfluoropyridinated BIMs and N,N´-bis(perfluoropyridyl) bis(indolyl)methane derivatives, as major and minor products, respectively. The structures of all the compounds were confirmed by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. [ABSTRACT FROM AUTHOR]

In this research, highly efficient protocols for the production of pyrido[2,3-d:6,5-d′]dipyrimidine and bis(pyrazolyl)methane derivatives using an acid ionic liquid namely [Et3N-SO3H][MeSO3] have been reported (bis(pyrazolyl)methanes have been produced via two methods, the pseudo three-component and the pseudo five-component reactions). [Et3N-SO3H][MeSO3] was superior than many of the reported catalysts in terms of two or more of these factors: turnover frequency (TOF), turnover number (TON), the reaction temperature, yield, the reaction time, simplicity in workup, and the reaction conditions. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate the in vitro antibacterial effects of a p‐Cymene‐based bis(pyrazolyl)methane derivative (SC‐19) to advance in developing alternative therapeutic compounds to fight against bacterial isolates from patients with otitis externa (OE). Methods: Eighteen swab specimens were collected from patients aged over 18 years diagnosed with OE within at least 7 days of symptom onset, contaminated by only one bacterium type: Pseudomonas aeruginosa (n = 5); Staphylococcus aureus (n = 8); Klebsiella aerogenes (n = 2); Serratia marcescens (n = 1); Morganella morganii (n = 2). To appraise antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC) assays were run at different SC‐19 concentrations. Results: When using SC‐19, S. aureus strains showed less bacterial growth, but no bactericidal effect was observed. The MIC and MBC of SC‐19 were 62.5 and 2000 μg/ml against S. aureus and were >2000 μg/ml against the other isolates obtained from OE, respectively. In addition, the MBICs and MBECs of SC‐19 against S. aureus were 125 and >2000 μg/ml, respectively. Conclusion: Nowadays the acquired antibiotic resistance phenomenon has stimulated research into novel and more efficient therapeutic agents. Hence, we report that, helped by the structural diversity fostered herein by a range of bis(pyrazolyl)methane derivatives, SC‐19 can be a promising alternative therapeutic option for treating OE caused by S. aureus given the observed effects on both planktonic state and biofilm. Level of Evidence: IV [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of cobalt(II)-based dyes were synthesized using bis(pyrazolyl) methane derivatives. • All the compounds were duly characterized by spectroscopic and analytical methods. • Direct and indirect optical band gaps of the complexes were obtained from Tauc plot method and are compared to the DFT derived HOMO-LUMO band gaps. • All the complexes were investigated for their efficacy as sensitizer in dye-sensitized solar cell application. Among the tested compounds, complexes containing carboxylic anchoring groups exhibited the best performance. A series of eight cobalt(II)-based dyes was synthesised using pyrazole and bis(pyrazolyl) methane derivatives. The new dyes were equipped with suitable anchoring functionalities, such as, carboxylic acid or thiocyanate groups, either on the ligand backbone or as a co-ligand to the metal center. All the synthesized compounds were characterized by various spectro-analytical techniques. The HOMO and LUMO energy gap of the dye molecules were determined theoretically by using B3LYP method. The opto-electronic and electrochemical properties of the dyes were analyzed by UV–visible spectroscopy and cyclic voltammetry studies respectively. The photo sensitizing capacity of all the synthesized cobalt-complexes was determined with a help of solar cell constructed using dye-TiO 2 coated FTO anode, platinum coated FTO cathode and an iodine based redox mediator. Among the tested compounds, complexes C8 and C9 which contain carboxylic anchoring groups exhibited the best performance. [ABSTRACT FROM AUTHOR]

Herein, we present an improved protocol for the synthesis of bis(indolyl)methanes using 6 mol% [BCMIM][Cl] ionic liquid via facile, one-pot, metal-free synthesis in aqueous ethanol at ambient temperature. In 15–55 min, a series of 48 derivatives were obtained in up to 94 % yields and were characterized using several spectroscopic techniques. UV–visible and fluorescence spectroscopies were used to investigate the photophysical behaviour of the synthesized bis-indole derivatives. The absorption and emission spectra exhibit the wavelength λ max at 298–379 nm and 327–352 nm, respectively. Theoretical calculations show a similar trend to the experimental investigations. The synthesized derivatives were assessed for their binding affinities with Bovine Serum Albumin (BSA) using AutoDock Vina. The results revealed a spectrum of affinities ranging from −7.9 to −10.5 kcal mol−1. [Display omitted] The highlights of this work are as follows. • A very broad substrate scope of over 48 bis-indole derivatives. • Investigation of photophysical parameters of selected bis-indoles. • DFT and TD-DFT calculations at B3LYP-6-31G (d, p) level of theory. • Biomolecular interaction studies with BSA by Molecular Docking. [ABSTRACT FROM AUTHOR]

A simple, mild, eco-friendly, general and convenient approach has been developed for the synthesis of various trisubstituted methane derivatives via one-pot pseudo three-component reactions between one equivalent of aromatic aldehydes and two equivalents of 6-amino-uracils or dimedone respectively using a catalytic amount of mandelic acid as a low cost, commercially available, efficient organo-catalyst in aqueous ethanol at room temperature. [ABSTRACT FROM AUTHOR]

In this paper, bis (indol-3-yl) methanes (BIMs) were synthesised and evaluated for their inhibitory activity against α-glucosidase and α-amylase. All synthesised compounds showed potential α-glucosidase and α-amylase inhibitory activities. Compounds 5 g (IC50: 7.54 ± 1.10 μM), 5e (IC50: 9.00 ± 0.97 μM), and 5 h (IC50: 9.57 ± 0.62 μM) presented strongest inhibitory activities against α-glucosidase, that were ∼ 30 times stronger than acarbose. Compounds 5 g (IC50: 32.18 ± 1.66 µM), 5 h (IC50: 31.47 ± 1.42 µM), and 5 s (IC50: 30.91 ± 0.86 µM) showed strongest inhibitory activities towards α-amylase, ∼ 2.5 times stronger than acarbose. The mechanisms and docking simulation of the compounds were also studied. Compounds 5 g and 5 h exhibited bifunctional inhibitory activity against these two enzymes. Furthermore, compounds showed no toxicity against 3T3-L1 cells and HepG2 cells. A series of bis (indol-3-yl) methanes (BIMs) were synthesised and evaluated inhibitory activities against α-glucosidase and α-amylase. Compound 5g exhibited promising activity (IC50 = 7.54 ± 1.10 μM) against α-glucosidase. Compound 5s exhibited promising activity (IC50 = 30.91 ± 0.86 μM) against α-amylase. In silico studies were performed to confirm the binding interactions of synthetic compounds with the enzyme active site. [ABSTRACT FROM AUTHOR]

A series of new organic hybrid polyoxovanadate clusters [V4O4(μ-OH)2(acac)2(Htri)2] (1, H3tri = tris(hydroxymethyl) aminomethane, acac = acetylacetone), [V4O4(acac)2(Htri)2(L)2] {HL = methanol (2), ethanol (3a and 3b), ethylene glycol (4) and benzyl alcohol (5)}, {V4O4(H2O)2(tri-acetamide)2(CH3COO)2} (6, H3tri-acetamide = N-(2-hydroxy-1,1-bis-hydroxymethyl-ethyl)-acetamide), [V6O8(μ-OH)2(Htri)3]·6H2O (7) and [V14O18(tri)2(Htri)6(HCOO)(CH3COO)]·2H2O (8) were prepared by hydro(solvo)thermal methods and characterized structurally. 1 contains [VO(OH)(acac)] and [VO2(Htri)] units, which are further interconnected via common edges to build a tetravanadyl cluster [V4O4(OH)2(acac)2(Htri)2] with the double-deficient cube [V4O6]. The tetravanadyl cluster frameworks of 2–5 can be derived from the tetravanadyl cluster of 1 by replacing two –OH groups with two deprotonated organic alcohol ligands, namely, CH3O− (2), CH3CH2O− (3a and 3b), HO(CH2)2O− (4) and C6H5CH2O− (5). Interestingly, both 3a and 3b have the same chemical structure, but they exhibit different conformational polymorphisms [denoted as α-type (3a) and β-type (3b)]. Such conformational polymorphisms within the polyoxovanadate clusters incorporating tris(hydroxymethyl)methane derivatives emerged for the first time. 6 displays another tetravanadyl cluster {V4O4(H2O)2(tri-acetamide)2(CH3COO)2} with a [V4O16] fragment, where the tri-acetamide unit comes from the amidation reaction of H3tri and acetic acid and caps the tetrahedral void of the tetravanadyl cluster. The polyoxovanadate cluster of 7 can originate from the Lindqvist-type hexavanadyl cluster [V6O19] by replacing nine μ-oxides with nine alkoxides of three tri-acetamide3− ligands. 8 exhibits a fully reduced tetradecavanadyl cluster based on the linkage of two heptavanadyl clusters via two O bridges. The magnetic properties of 1–8 show typical antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

We prepared acetic acid derivatives using three different frameworks, calix[4]arene, alkenyltrimethylol, and trihydroxytriphenylmethane, which differ in the number and size of their coordination sites. We further investigated the extraction properties for aluminum group metal ions. All three extraction reagents exhibited increased extraction compared with the corresponding monomeric compounds, owing to structural effects. The extraction reaction and extraction equilibrium constants were determined using a slope analysis. Their extraction abilities, separation efficiencies, and potential coordination modes are discussed using the extraction equilibrium constants, half-pH values, and spectroscopic data. The calix[4]arene and trihydroxytriphenylmethane derivatives demonstrated allosteric co-extraction of indium ions (In3+) with an unexpected stoichiometry of 1:2. [ABSTRACT FROM AUTHOR]

The scarcity of reliable methods for synthesizing chiral gem‐diarylmethine borons limits their applications. Herein, we report a method for highly enantioselective dirhodium‐catalyzed B−H bond insertion reactions with diaryl diazomethanes as carbene precursors. These reactions afforded chiral gem‐diarylmethine borane compounds in high yield (up to 99 % yield), high activity (turnover numbers up to 14 300), high enantioselectivity (up to 99 % ee) and showed unprecedented broad functional group tolerance. The borane compounds synthesized by this method could be efficiently transformed into diaryl methanol, diaryl methyl amine, and triaryl methane derivatives with good stereospecificity. Mechanistic studies suggested that the borane adduct coordinated to the rhodium catalyst and thus interfered with decomposition of the diazomethane, and that insertion of a rhodium carbene (generated from the diaryl diazomethane) into the B−H bond was most likely the rate‐determining step. [ABSTRACT FROM AUTHOR]

Pyrazole and its derivatives are an important class of heterocyclic compounds, present in several biologically and medicinally active compounds. Compounds containing 2,4-dihydro-3H-pyrazol-3-one structural motif, including 4,4′-(arylmethylene)-bis-(1H-pyrazol-5-ols), have attracted interest because they exhibit a wide range of biological activities and as the chelating and extracting reagents for different metal ions. There are two main strategies to the synthesis of bis(pyrazolyl)methane derivatives. The first involves the one-pot pseudo three-component reactions of 3-methyl-5-pyrazolone derivatives and aldehydes, and the second approach is the one-pot pseudo five-component reactions of β-keto esters, hydrazins and aldehydes. This review includes the recent investigation in the multi-component synthesis and their applications of bis(pyrazolyl)methanes and describes the literature reports for the period of 2014 to early 2021. [ABSTRACT FROM AUTHOR]

The scarcity of reliable methods for synthesizing chiral gem‐diarylmethine borons limits their applications. Herein, we report a method for highly enantioselective dirhodium‐catalyzed B−H bond insertion reactions with diaryl diazomethanes as carbene precursors. These reactions afforded chiral gem‐diarylmethine borane compounds in high yield (up to 99 % yield), high activity (turnover numbers up to 14 300), high enantioselectivity (up to 99 % ee) and showed unprecedented broad functional group tolerance. The borane compounds synthesized by this method could be efficiently transformed into diaryl methanol, diaryl methyl amine, and triaryl methane derivatives with good stereospecificity. Mechanistic studies suggested that the borane adduct coordinated to the rhodium catalyst and thus interfered with decomposition of the diazomethane, and that insertion of a rhodium carbene (generated from the diaryl diazomethane) into the B−H bond was most likely the rate‐determining step. [ABSTRACT FROM AUTHOR]

A sulfonated polyethylene glycol-supported nano-magnetite (Fe3O4@PEG-SO3H) has been prepared, characterized, and evaluated as a magnetically recoverable core–shell nanocomposite catalyst for the synthesis of bis(indolyl)methane derivatives through the one-pot reaction of indole and aldehydes. Green and eco-friendly reaction profile, mild reaction conditions (room temperature), simple procedure, short reaction times, and excellent yields make this method versatile and demonstrate its practical merit for the synthesis of the title compounds with potential pharmacological activity. Furthermore, the excellent catalytic performance, thermal stability, and easy separation and reusability of the prepared nanocatalyst without significant deterioration in its catalytic activity make it a good heterogeneous system and a superior alternative to the existing protocols. [ABSTRACT FROM AUTHOR]

Herein, an air‐stable, molecularly defined NNN−Mn(II) pincer complex catalyzed acceptorless dehydrogenative coupling of alcohols with indoles is reported. A wide variety of symmetrical and unsymmetrical bis(indolyl)methane derivatives as well as some structurally important products such as Vibrindole A, Turbomycin B alkaloid, Antileukemic, and Anticancer agents were synthesized. Mechanistic studies illustrate the importance of the NH moiety in the complex and the crucial role of metal‐ligand cooperation during catalysis. [ABSTRACT FROM AUTHOR]

Herein, we report a KIO4‐mediated, sustainable and chemoselective approach for the one‐pot C(sp2)−H bond hydroxymethylation or methylenation of imidazo‐heteroarenes with formaldehyde, generated in situ via the oxidative cleavage of ethylene glycol or glycerol (renewable reagents) through the Malaprade reaction. In the presence of ethylene glycol, a series of 3‐hydroxymethyl‐imidazo‐heteroarenes was obtained in good to excellent yields. These compounds are important intermediates to access pharmaceutical drugs, e.g. Zolpidem. Furthermore, by using glycerol, bis(imidazo[1,2‐a]pyridin‐3‐yl)methane derivatives were selectively obtained in good to excellent yields. [ABSTRACT FROM AUTHOR]

Herein, we report a KIO4‐mediated, sustainable and chemoselective approach for the one‐pot C(sp2)−H bond hydroxymethylation or methylenation of imidazo‐heteroarenes with formaldehyde, generated in situ via the oxidative cleavage of ethylene glycol or glycerol (renewable reagents) through the Malaprade reaction. In the presence of ethylene glycol, a series of 3‐hydroxymethyl‐imidazo‐heteroarenes was obtained in good to excellent yields. These compounds are important intermediates to access pharmaceutical drugs, e.g. Zolpidem. Furthermore, by using glycerol, bis(imidazo[1,2‐a]pyridin‐3‐yl)methane derivatives were selectively obtained in good to excellent yields. [ABSTRACT FROM AUTHOR]

A promising strategy to break through the selectivity‐conversion limit of direct methane conversion to achieve high yields is the protection of methanol via esterification to a more stable methyl ester. We present an aerobic methane‐to‐methyl‐ester approach that utilizes a highly dispersed, cobalt‐containing solid catalyst, along with significantly more favorable reaction conditions compared to existing homogeneously‐catalyzed approaches (e.g. diluted acid, O2 oxidant, moderate temperature and pressure). The trifluoroacetic acid medium is diluted (<25 wt %) with an inert fluorous co‐solvent that can be recovered after the separation of the methyl trifluoroacetate via liquid–liquid extraction at ambient conditions. Silica‐supported cobalt catalysts are highly active in this system, with competitive yields and turnovers in comparison to known aerobic transition metal‐based catalytic systems. [ABSTRACT FROM AUTHOR]

A promising strategy to break through the selectivity‐conversion limit of direct methane conversion to achieve high yields is the protection of methanol via esterification to a more stable methyl ester. We present an aerobic methane‐to‐methyl‐ester approach that utilizes a highly dispersed, cobalt‐containing solid catalyst, along with significantly more favorable reaction conditions compared to existing homogeneously‐catalyzed approaches (e.g. diluted acid, O2 oxidant, moderate temperature and pressure). The trifluoroacetic acid medium is diluted (<25 wt %) with an inert fluorous co‐solvent that can be recovered after the separation of the methyl trifluoroacetate via liquid–liquid extraction at ambient conditions. Silica‐supported cobalt catalysts are highly active in this system, with competitive yields and turnovers in comparison to known aerobic transition metal‐based catalytic systems. [ABSTRACT FROM AUTHOR]

Fluorine incorporation into organic molecules is expected to lower the pKa of neighboring functionality via its strong electron‐withdrawing effect, and this strategy has been widely exploited in diverse disciplines. Herein, we report a striking anomalous α‐fluorine substitution effect on the α‐Csp3‐H acidity. We have experimentally measured the pKa values of a series of popular nucleophilic monofluoromethylating reagents α‐fluoro(phenylsulfonyl)methane derivatives as well as their C‐H analogues by Bordwell's overlapping indicator method in dimethyl sulfoxide solution. Contrary to expectations, we found that α‐fluorine substituent does not generally enhance but rather weaken the α‐Csp3‐H acidity of most (phenylsulfonyl)methane derivatives. DFT computations reproduce and provide insight into the anomalous α‐fluorine effect. A correlation was identified between the C‐H pKa of (phenylsulfonyl)methane derivatives and Mayr's nucleophilicity parameter (N) of the corresponding carbanions. [ABSTRACT FROM AUTHOR]

Fluorine incorporation into organic molecules is expected to lower the pKa of neighboring functionality via its strong electron‐withdrawing effect, and this strategy has been widely exploited in diverse disciplines. Herein, we report a striking anomalous α‐fluorine substitution effect on the α‐Csp3‐H acidity. We have experimentally measured the pKa values of a series of popular nucleophilic monofluoromethylating reagents α‐fluoro(phenylsulfonyl)methane derivatives as well as their C‐H analogues by Bordwell's overlapping indicator method in dimethyl sulfoxide solution. Contrary to expectations, we found that α‐fluorine substituent does not generally enhance but rather weaken the α‐Csp3‐H acidity of most (phenylsulfonyl)methane derivatives. DFT computations reproduce and provide insight into the anomalous α‐fluorine effect. A correlation was identified between the C‐H pKa of (phenylsulfonyl)methane derivatives and Mayr's nucleophilicity parameter (N) of the corresponding carbanions. [ABSTRACT FROM AUTHOR]

Herein we report the multicomponent synthesis of the bis(indolyl)methane derivatives in a ball mill. The reaction was carried out under solvent-free conditions using only the Lewis acid-surfactant-SiO2 composite nanocatalyst (LASSC) prepared in situ. The unsymmetrical bis(indolyl) methane derivatives containing nitro or fluorine substitution with a yield of 72%–92% were obtained in a short reaction time. Within we verified that under the action of the combined catalyst of AlCl3·6H2O + SDS + SiO2, the method of preparing unsymmetrical bis(indolyl)methane by mechanical grinding without solvent has obvious advantages. Finally, we inspected that the catalysis system can be used eight times without a significant decrease in activity. [ABSTRACT FROM AUTHOR]

This study used aryl diazonium salts as catalysts to catalyze reductive aminations of carbonyls and the synthesis of bis (3-indolyl)methane derivatives. The catalytic system showed good tolerance to substituents in the substrate in these two reactions. The separation yields of reductive aminations range from moderate to excellent. The separation yield of the reaction for synthesizing bis(3-indolyl)methane derivatives ranges from good to excellent. Finally, we also explored the catalytic behavior of aryl diazonium salts in amination reduction reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

The novel acidic ionic liquid [BEMIM][HSO 4 ] was prepared and characterized by FT-IR, 1H NMR, 13C NMR, DEPT-135, LC-Mass, and elemental analysis techniques. It was examined as a catalyst for the synthesis of bis-indolyl methane derivatives at ambient temperature, and an important advantage was that it required only short reaction times. The crude bis-indolyl methane products could be purified by a simple recrystallization process, avoiding time-consuming chromatography. The catalyst was reusable, and even after five runs, an insignificant loss in the activity of the catalyst was observed. The chemical integrity of the recovered catalyst after the fifth run was confirmed by FT-IR, 1H NMR, and Mass analysis. This reaction has a high value of the environmental factor (E). [Display omitted] • An innovative and highly efficient acidic ionic liquid catalytic process was developed. • Catalyst is recyclable, eco-friendly, safe to handle and facile to prepare. • High conversion of bis-indolyl methanes obtained at ambient temperature in a shorter time. • Purification of crude products is simply done by a recrystallization process. [ABSTRACT FROM AUTHOR]

We have prepared a sustainable heterogeneous catalyst (GO- N -PTA) by immobilization of PTA via functionalization of APTES on graphene oxide (GO) surface. Prepared catalyst was found to be highly active for synthesis of bis(indolyl)methane derivatives, and could be recycled consecutively for three times and used in organic synthesis in large scale. [Display omitted] Phosphotungstic acid was immobilized hydrothermally on the surface of 3-aminopropyltriethoxysilane-grafted graphene oxide (GO- N -PTA) and used as a heterogeneous solid acid catalyst for the synthesis of bis(indolyl)methane derivatives. X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, BET isotherm, FESEM with EDS and elemental mapping, FETEM, X-Ray photoelectron spectroscopy (XPS), Raman spectroscopy techniques were used to characterize the synthesized catalyst. The catalyst was found to be highly effective for the synthesis of bis(indolyl)methane derivative compounds with yields in the ranges of 94–96.5 % under the optimized reaction conditions. The catalyst was recycled upto 3rd cycle for a specific reaction, that produced 94.5% yield with marginal loss in yield compared to the fresh catalyst (96.5%) depicting the hetreogneiety and sustainability of the present GO- N -PTA catalyst. This study provides the development of sustainable heterogeneous GO- N -PTA catalyst towards the synthesis of highly pharmaceutically important bis(indolyl)methanes derivative compounds. [ABSTRACT FROM AUTHOR]

For the first time, chemical modification of raw Luffa with hydrogen sulfate moieties was investigated. For this purpose ammonium hydrogen sulfate moieties were immobilized on the surface of Luffa. This chemical modification performed by reaction of 3-aminopropyltriethoxy silane with raw Luffa and sulfonation of amine groups using sulfuric acid. The morphology of catalyst was investigated by Fourier transform spectroscopy, X-ray diffraction, thermogravimetric analysis, field emission scanning electron microscope, elemental-mapping, and energy dispersive X-Ray spectroscopy techniques. The catalytic performance of the synthesized catalyst was examined in the synthesis of coumarin and bis(indolyl)methane derivatives. Our method introduced a green protocol in using of a plant for the preparation of catalyst and one-pot solventless media for the synthesis of coumarins and bis(indolyl)methanes. Some of the advantages of our method are high yields of products, short reaction times, recyclability of catalyst, easy workup, and separation of catalyst and products. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: Securines A—E, three dimeric diarymethane derivatives (1—3) and two enantiomeric diarymethane derivative monomers (4 and 5), were isolated and characterized from the medicinal plant Securidaca inappendiculata. Compounds 1 and 2 are a pair of enantiomeric diarymethane derivative dimers, and compound 3 is a mesomeric diarymethane derivative dimer. Their structures were determined by a combination of spectroscopic data, X‐ray crystallography, electronic circular dichroism (ECD) analysis, and computational ECD calculations. Dimeric compounds 1—3 showed moderate antiplasmodial activities with IC50 values of 0.9, 1.4, and 1.5 μM, respectively. [ABSTRACT FROM AUTHOR]

MCM‐41‐supported nanoscale guanine bonded with Zr (IV) was prepared using sol–gel method and characterized by FT‐IR, Raman, XRD, BET, TGA, EDX, ICP, AAS, X‐Ray mapping, SEM and TEM techniques. This compound was employed as an efficient, chemoselectivity and green heterogeneous catalyst in order to prepare a series of benzo[a]benzo[6,7]chromeno[2,3‐c]phenazine and spiro[benzo[a]benzo[6,7]chromeno[2,3‐c] phenazine] derivatives by one‐pot, four‐component domino reaction from the 2‐hydroxy‐1,4‐naphthoquinone, benzene‐1,2‐diamines, 2‐hydroxy‐1,4‐naphthoquinone and carbonyl compounds in PEG, at 100 °C and, also, Bis (pyrazolyl) methane derivatives using aldehydes and 3‐Methyl‐1‐phenyl‐5‐pyrazolone in ethanol under reflux condition. Results indicated that all products were synthesized in short reaction times and high yields in the ranges 78–99%. The Zr‐guanine‐MCM‐41 can be recycled four runs without any significant loss of its catalytic activity. In addition, the stability of the catalyst was confirmed by metal leaching, heterogeneity tests, SEM and FT‐IR techniques. [ABSTRACT FROM AUTHOR]

A catalyst‐free, environmentally benign, and simple procedure has been developed for the efficient synthesis of novel 2H‐furo[3,2‐c]chromene‐2,4(3H)‐dione and 3,3′‐((arylamino)methylene)bis(4‐hydroxycoumarin) derivatives from one‐pot three‐component condensation of 4‐hydroxycoumarin, glyoxalic acid monohydrate and various amines in water under reflux condition. In this green synthetic protocol, the solvent water itself catalyzed the reaction via hydrogen bonding. One‐pot, high yields, short reaction times, simple operation, environmental friendly and easy workup procedure are highlights. This is the first report for the synthesis of 2H‐furo[3,2‐c]chromene‐2,4(3H)‐dione and arylamino‐bis(coumarin)methane derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] Novel 3-azaxanthenes have been synthesized via acid-catalyzed one-pot Friedel–Crafts reaction of pyridoxal/pyridoxal-5'-phosphate with naphthols followed by dehydration of the intermediate bis(2-hydroxyaryl)-(pyridin-4-yl)methane derivatives. The cytotoxicity of the obtained 3-azaxanthenes against M-HeLa and HuTu-80 tumor cell lines is comparable to that of tamoxifen, whereas the cytotoxicity against normal cell line is absent in the tested concentrations range, which makes this class of compounds interesting for further studies. [ABSTRACT FROM AUTHOR]

A core–shell Fe3O4@silica magnetic nanocomposite functionalized with 3‐amino‐5‐mercapto‐1,2,4‐triazole (Fe3O4/SiO2/PTS/AMTA) was prepared using Fe3O4 with silica layer, and its surface was modified with 3‐amino‐5‐mercapto‐1,2,4‐triazole. The novel synthesized magnetite nanocomposite was characterized using various techniques. The catalytic activity of Fe3O4/SiO2/PTS/AMTA was demonstrated in the synthesis of bis(indolyl)methane derivatives under solvent‐free conditions. Some of the bis(indolyl)methane derivatives were synthesized through one‐pot, three‐component reaction of 1 mol of various benzaldehydes or ketones with 2 mol of indole in the presence of Fe3O4/SiO2/PTS/AMTA in good to excellent isolated yields. In addition, the catalyst could be recovered and used for several reaction runs without loss of catalytic activity. The stability of recycled catalyst was investigated. This method has some advantages including experimental simplicity, good to excellent yields, solvent‐free conditions and stability and reusability of the catalyst. [ABSTRACT FROM AUTHOR]

In this research, a rapid, green and efficient protocol for synthesis of bis (pyrazolyl)methane derivatives in the presence of Pd(0)‐guanidine@MCM‐41 catalysts under solvent‐free conditions by the following two methods has been reported: (i) via the one‐pot pseudo five‐component reaction among phenylhydrazine (2 equivalents), ethyl acetoacetate (2 equivalents) and aromatic aldehydes (1 equivalent); and (ii) the one‐pot pseudo three‐component reaction between 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐one (2 equivalents) and aromatic aldehydes (1 equivalent). Some advantages of this protocol include: green conditions, extremely short times, high efficiency, proper one‐pot operation, generality of method, easy work‐up and recyclability, and reusability of the catalyst up to five times without significant loss in catalytic activity. [ABSTRACT FROM AUTHOR]

Effective research in green chemistry requires new and applicable synthetic techniques. In this regard, for the first time, a green method is reported for the immobilization of iminodiacetic acid–Ni complex on the surface of CoFe2O4 magnetic nanoparticles. The obtained nanocomposite was characterized via chemical and physical techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), inductively coupled plasma-optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), X-ray mapping and thermal gravimetric analysis (TGA) techniques. In addition, catalytic activity of the as-prepared nanocomposite was examined in the synthesis of polyhydroquinoline and bis(pyrazolyl)methane derivatives in green conditions. It was observed that all the products were obtained during short reaction time and in good to excellent yields. Importantly, the catalyst was easily recovered and recycled by magnetic field for five successive times without noticeable decrease in its catalytic activity. [ABSTRACT FROM AUTHOR]