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Four new steroidal glycosides, protolinckiosides A - D (1 - 4, resp.), were isolated along with four previously known glycosides, 5 - 8, from the MeOH/EtOH extract of the starfish Protoreaster lincki. The structures of 1 - 4 were elucidated by extensive NMR and ESI-MS techniques as (3β,4β,5α,6β,7α,15α,16β,25S)-4,6,7,8,15,16,26-heptahydroxycholestan-3-yl 2-O-methyl-β-d-xylopyranoside (1), (3β,5α,6β,15α,24S)-3,5,6,8,15-pentahydroxycholestan-24-yl α-l-arabinofuranoside (2), sodium (3β,6β,15α,16β,24R)-29-(β-d-galactofuranosyloxy)-6,8,16-trihydroxy-3-[(2-O-methyl-β-d-xylopyranosyl)oxy]stigmast-4-en-15-yl sulfate (3), and sodium (3β,6β,15α,16β,22E,24R)-28-(β-d-galactofuranosyloxy)-6,8,16-trihydroxy-3-[(2-O-methyl-β-d-xylopyranosyl)oxy]ergosta-4,22-dien-15-yl sulfate (4). The unsubstituted β-d-galactofuranose residue at C(28) or C(29) of the side chains was found in starfish steroidal glycosides for the first time. Compounds 1 - 4 significantly decreased the intracellular reactive oxygen species (ROS) content in RAW 264.7 murine macrophages at induction by proinflammatory endotoxic lipopolysaccharide (LPS) from E. coli.

A novel route for synthesis of 2-acyl-1,1,3,3-tetracyanopropenides (ATCN) salts in high yields and excellent purities starting from readily available methyl ketones, malononitrile, bromine, and alkali metal acetates is reported. The starting aryl(heteroaryl) methyl ketones were oxidized to the corresponding α-ketoaldehydes by new a DMSO–NaBr–H2SO4 oxidation system in yields up to 90% within a short reaction time of 8–10 min. The subsequent stages of ATCN preparation are realized in aqueous media without use of any toxic solvents, in accordance with principle 5 of “green chemistry”. Lithium, sodium, potassium, rubidium, and cesium 2-benzoyl-1,1,3,3-tetracyanopropenides were characterized by X-ray diffraction analysis. These salts show a good potential for synthesis of five- and six-membered heterocycles and may serve as potentially useful ligands in coordination and supramolecular chemistry.

Diels—Alder reaction between cinnamaldehydes (I) and cyclopentadiene (II) in the presence of (S)-pyrrolidine derivative as catalyst and perchloric acid as additive yields cycloaddition products favouring the endo formation (IV).

Solid-acid catalytic materials such as ZrO2-Al2O3 containing 80 mol% of ZrO2 were prepared by the solution combustion method (SCM) using different fuels such as urea, hexamethylene tetramine, glycine, and sucrose. All the prepared solid acid catalytic materials were characterized for their physico-chemical properties like crystalinity, acidity, functionality and morphology. These materials were evaluated for their catalytic activity in the synthesis of a series of novel substituted benzimidazoles. The reaction conditions were optimized by varying the solvents, reaction temperature, weight of solid acid catalyst, molar ratio of the reactants, and reaction time. The ZrO2-Al2O3 solid acid catalytic material prepared by urea as a fuel was found to be highly active, recyclable, and reusable in the synthesis of benzimidazoles. A possible reaction mechanism for the synthesis of benzimidazoles is also proposed.

Microcrystalline NH4V3O7 is prepared by hydrothermal treatment of an aqueous solution of NH4VO3 to which citric acid is given (pH 4—6, autoclave, 180—200 °C, 24 h).

An efficient green method for the selective synthesis of new 4,5-disubstituted 1H-1,2,3-triazoloalkylidenes via the β-cyclodextrin-catalyzed three-component reaction between substituted propynals, trimethylsilyl azide and malononitrile in water at room temperature has been developed.

An efficient oxidation of iodoarenes to the corresponding iodylarenes is achieved without the need for any catalyst.

A new one-pot method for the synthesis of 2,3,4,6,7,8,9,10-octahydro-1H-pyrazino[1,2-a]quinolines was developed based on a three-component reaction between methyl (3-oxopiperazin-2-ylidene)acetate, aromatic aldehydes, and cyclohexane-1,3-diones. It was shown by HPLC-MS analysis that this cascade reaction involved a sequence of steps including condensation between 1,3-diketone and aldehyde, addition of heterocyclic enaminone as a C-nucleophile, and intramolecular heterocyclization.

Polycrystalline Cu3Eu(SeO3)2O2Cl and Cu3Lu(SeO3)2O2Cl are prepared by solid state reaction of Eu2O3 (Lu2O3), CuO, CuCl2, and SeO2 (evacuated quartz tubes, 1.

The title compound is synthesized by solid state reaction of stoichiometric amounts of LiCo0.5Fe0.5PO4 and NaF (1.

The sequential synthesis of eleven novel 1-trimethysilyl-2-arylcyclohexenes 4a–k from 1-bromo-2-chlorocyclohexene (1) is reported. The Suzuki cross coupling of 1 with eleven aryl boronic acids 2a–k gave the 1-chloro-2-arylcyclohexenes 3a–k in >90% yields. Wurtz–Fittig coupling reaction of 3a–k with metallic sodium and chlorotrimethylsilane in anhydrous ether solvent afforded the novel anionic synthons: 1-trimethylsilyl-2-arylcyclohexenes 4a–k in 65–87% yields. The cyclic vinylsilanes 4a–j are liquids, and 1-trimethylsilyl-2-biphenylcyclohexene (4k) exists as a solid. The crystal structure of 4k is discussed. A plausible mechanism for the Wurtz–Fittig reaction and formation of vinylsilanes is highlighted.

The acid hydrazide derivatives 2 were converted into pyrazolone, triazinone, and schiff bases. However, the reaction of Schiff base 12 with malononitrile or thioglycolic acid gives the pyrazolotriazinone or thiazolidinone derivative, respectively. The structures of the newly synthesized compounds were established on the basis of IR, 1H-NMR, mass spectral data, and elemental analyses. The antimicrobial activities of the synthesized compounds were examined against two types of bacteria and two types of fungi. Some of the tested compounds showed promising activities.

In the course of isolation of fungal luciferin from bioluminescent fungus Neonothopanus nambi, structures of novel nambiscalarane, Aurisin Z, trans-α-hydroxy-γ-phenylbutyrolactone, methyl 4-butyramidobenzoate as well as known nambinones A and C and polyhydroxylated sterol were identified.

Iodine-mediated synthesis of 3-sulfenylimidazo[1,5-a]pyridines via C–H functionalization has been achieved using dithioesters, 2-methylaminopyridines and sulfonyl hydrazides. A library of 3-sulfanylimidazopyridines and imidazopyridines with broad functionalities are synthesized under metal-free reaction conditions.

A general and concise approach to thermally and hydrolytically stable alkyl 2,3-dihydroazete-2,3-di-/2,2,3-tricarboxylates from alkyl 2-bromoazirine-2-carboxylates or 4-bromo-5-alkoxyisoxazoles is reported. The synthesis involves the formation of 2-azabuta-1,3-diene by the reaction of rhodium carbenoid with isoxazole or azirine followed by cyclization/hydrodebromination cascade. The latter reaction is the first example of the selective hydrodehalogenation of a valence isomer under equilibrium conditions. In vitro cytotoxicity tests on THP-1 cell line revealed that the 2,3-dihydroazetes greatly differ in their ability to induce apoptosis and/or necrosis. To adequately describe and quantitatively assess these properties, the difference between the two areas under the curves of concentration dependency of apoptosis/necrosis induction within the concentration range was used. Trimethyl 4-phenyl-2,3-dihydroazete-2,2,3-tricarboxylate was found to display the maximal apoptotic potential coupled with high cytotoxic and minimal necrotic potential.

Cinnamic acids are intermediates with significant potential for synthesis of several industrially important chemicals. Classically, cinnamic acids are produced through Knoevenagel condensation of aromatic aldehydes and malonic acid in the presence of an organocatalyst and large amounts of carcinogenic pyridine. An alternative pyridine free reaction scheme for Knoevenagel condensation of malonic acid and aromatic aldehydes was investigated by replacing pyridine with an aliphatic tertiary amine surrogate in toluene as the reaction medium. Of the three aliphatic tertiary amines used, namely, triethyl amine (TEA), trioctyl amine (TOA) and tributyl amine (TBA), only TEA afforded cinnamic acids in comparable yields to those obtained with pyridine. Validation through a computational analysis is attempted to provide an explanation for the observed role of TEA as an aliphatic N-base instead of TBA and TOA. The use of TEA as a mild base in place of pyridine can be seen as playing the dual role of a base catalyst as well as a phase transfer agent evidenced by the in-process ATR-FITR spectroscopy. Use of the TEA–toluene system in place of pyridine can be seen as resulting in a process that affords ease of handling, separation and recycling of the solvent and the catalyst.

A new synthetic method has been developed for the regioselective conversion of epoxides to vicinal chloro-/bromohydrins and vicinal dihalides by reaction with the system trihaloisocyanuric acid/tri­phenylphosphine in acetonitrile under mild and neutral conditions. The reactions proceed smoothly in high yield at room temperature and at reflux, respectively, over a short time.

Reaction of 6-aryl-3-trichloromethyl-1,2,4-triazines with 1-morpholinocyclopentene affords 4-aryl-1-dichloromethyl- 6,7-dihydro-5 H -cyclopenta[ c ]pyridines.

The optical and electrical properties are the two important dimensions of Indium oxide and its derivatives (indium tin oxide) and were well studied to understand the origin of wide electronic band gap and high electrical conductivity at room temperature. In 2 O 3 and its derivatives find many applications in electronic and optoelectronic domains based on the above properties. The recent discovery of ferromagnetism in In 2 O 3 at room temperature become a third dimension and lead to intensive research on enhancement of ferromagnetic strength by various means such as dopants and synthesis protocols and extrinsic parameters. The research lead to enormous experimental data and theoretical models proliferation over the past one decade with diverse insights into the origin of ferromagnetism in In 2 O 3 based dilute magnetic semiconductors. The experimental data and theoretical models of ferromagnetism in In 2 O 3 has been thoroughly surveyed in the literature and compiled all the data and presented for easy of understanding in this review. We have identified best chemical composition, geometry and synthesis protocols for strongest ferromagnetic strength and suitable theoretical model of magnetism has been presented in this review.

A new modified van Leusen strategy has been developed for the synthesis of biologically significant 5-substituted oxazoles by the reaction of (het)aryl methyl alcohols or benzyl bromides as precursors with tosylmethylisocyanide (TosMIC) under basic conditions. This method is efficient, takes place under mild reaction conditions, and is tolerant of various functional groups with high yield.

Benzophenone-sensitized reactions of 4-diazotetrahydrofuran-3(2H)-ones with H-donors such as tetrahydrofuran, 1,4-dioxane, cyclohexane and diethyl ether, occur without elimination of nitrogen and give rise to the corresponding N-substituted hydrazones or bis-hydrazonoethanes due to a formal insertion of the terminal N atom of diazo group into α-C−H bonds of ethers and aliphatic hydrocarbons, with yields of up to 78 %. Long-wavelength UV irradiation (λ>310 nm) is most suitable for this process, whereas oxygen molecules adequately quench the triplet excited state of the diazoketone and reduce the preparative yields of C−H-insertion products. Hence this photochemical reaction of diazoketones can be used for C−H functionalization of different aliphatic compounds.

In the past few years, we have seen intense interest grow in chemistry, toxicity and analysis of biogenic amines (BAs). Thus, a comprehensive review on clean-up and recent advances in analysis of biogenic amines (BAs) in human body and dairy products of foodstuffs are presented. Liquid-liquid extraction, solid phase extraction, solid phase microextraction, dispersive liquid-liquid microextraction (DLLME), cloud point extraction and hollow fiber-liquid phase microextraction represent the most common preconcentration techniques for BAs. HPLC, GC, TLC, spectrofluorimetry, capillary zone electrophoresis coupled with mass spectrometry are the most common analytical techniques used for analysis of BAs. DLLME techniques offer benefits over centrifugation, filtration and solid-phase extraction. The milestones and combination of nanotechniques in the DLLMEs field and green aspects of BAs in literature; advantages and drawbacks are addressed. A major focus on analysis of BAs revealed no use of coupling DLLME techniques with electroanalytical techniques in particular stripping voltammetry. Thus, voltammetric techniques at surface modified electrodes implemented with DLLME techniques is highly recommended for developing low cost and precise methods for analysis of BAs at ultra trace levels in foodstuffs. Conclusions have been drawn for future research is proposed.

The title arylation of amines with aryl bromides allows the synthesis of a wide range of secondary and tertiary aryl amines in high yields.

Sonication (or ultrasound irradiation) has emerged as a potential technique for the intensification of diverse physical/chemical/biological processes. In recent years, sonication has been applied in the synthesis of liquid biofuels, such as biodiesel, and bioalcohols, such as ethanol. The process of bioalcohol synthesis comprises four steps, viz. acid pretreatment, alkaline delignification, enzymatic hydrolysis and fermentation. Significant literature has been published in the last decade on the application of ultrasound for the intensification of all the steps of bioalcohol synthesis. In this paper, a critical review and analysis of the literature on ultrasound-assisted bioalcohol synthesis has been presented. This review has addressed all four steps of bioalcohol synthesis. Essentially, the literature in the areas of ultrasound-assisted biomass pretreatment, delignification and hydrolysis has been reviewed, followed by an analysis of the literature on ultrasound-assisted fermentation. Finally, the mechanistic investigations of the various steps of bioalcohol synthesis have been reviewed, highlighting the synergistic links between the physical/chemical effects of ultrasound and cavitation and the basic physical/chemical mechanisms of the steps of bioalcohol synthesis. The critical analysis of the literature in this review has not only demonstrated the efficacy of ultrasound in the intensification of all the steps of bioalcohol synthesis, but has also brought to light the underlying mechanistic issues; this could provide guidelines for the design and optimization of commercial scale bioalcohol processes.

The chemoselectivity of the title reaction is shown to be depending on the type of the utilized hydrazonoyl halide.

In this article, the catalytic activity of titania-supported gold nanoparticles (Au/TiO2) was studied for the selective oxidation of amines into nitroso compounds using hydrogen peroxide (H2O2). Gold nanoparticles deposited on Degussa P25 polymorphs of titania (TiO2) have been found to promote the selective formation of a variety of nitroso arenes in high yields and selectivities, even in a large-scale synthesis. In contrast, alkyl amines are oxidized to the corresponding oximes under the examined conditions. Kinetic studies indicated that aryl amines substituted with electron-donating groups are oxidized faster than the corresponding amines bearing an electron-withdrawing functionality. A Hammett-type kinetic analysis of a range of para-X-substituted aryl amines implicates an electron transfer (ET) mechanism (ρ=−1.15) for oxidation reactions with concomitant formation of the corresponding N-aryl hydroxylamine as possible intermediate. We also show that the oxidation protocol of aryl amines in the presence of 1,3-cyclohexadiene leads in excellent yields to the corresponding hetero Diels–Alder adducts between the diene and the in situ formed nitrosoarenes.

[(THD-Dipp)AuOTf], supported by the strongly electron donating, sterically bulky THD-Dipp (1,3-bis(2,6-diisopropylphenyl)hexahydro-2H-1,3-diazepine-2-ylidene) seven-membered N-heterocyclic carbene ligand, efficiently promotes intermolecular addition of Ts- and Boc-hydrazine to arylalkynes under solvent-free conditions.

In the context of formation and stability of synthetic rock (SYNROC), studies on crystal structure and thermodynamic parameters of a mineral analogous material, namely calzirtite has been undertaken. The ambient temperature structural studies revealed a tetragonal (I41/acd) fluorite related super-structure with about 5% intermixing of Ti and Zr sites for calzirtite. High temperature structural studies indicated the retention of tetragonal structure of calzirtite up to 1673 K. The average axial thermal expansion coefficient of calzirtite between 297 and 1473 K is found to be 12.7 × 10−6/K for a-axis and 9.2 × 10−6/K along the c-axis. The thermodynamic parameters of calzirtite have been determined employing high temperature solution calorimetry. The standard molar enthalpy of formation of Ca2Zr5Ti2O16(s) at 298 K is found to be −8964.16 ± 12.59 kJ mol−1. The isobaric heat capacity of the compound has been derived from the enthalpy increment (HT-H298) data measured by drop calorimetric technique. Based on the experimental results thermodynamic functions like C p , m ° , S m ° , H ° , G ° , − ( G T ° − H 298 ° T ) , Δ f H 298 ° and Δ f G T ° for calzirtite (Ca2Zr5Ti2O16,s) has been generated.

The reaction of 3-aryl-N-(aryl)propiolamides with arenes in TfOH at room temperature for 0.5 h led to 4,4-diaryl-3,4-dihydroquinolin-2-(1H)-ones in yields of 44-98%. The obtained dihydroquinolinones were further transformed into the corresponding N-acyl or N-formyl derivatives. For the latter, the superelectrophilic activation of the N-formyl group by TfOH in the reaction with benzene resulted in the formation of N-(diphenylmethyl)-substituted dihydroquinolinones.

The reaction of 2-methyl-1-(phenylethynyl)-2,3,4,9-tetrahydro-1Н-β-carboline with activated alkynes in acetonitrile led to the formation of 1-vinyl-substituted β-carbolines and condensed azocines.

Solvent-free protocols for Miyaura borylation and the one-pot, two-step homocoupling of aryl halides are reported for the first time. Bis(dibenzylideneacetone)palladium(0) [Pd(dba)2] is an optimal source of palladium for Miyaura borylation, while for one-pot two-step homocoupling palladium(II) acetate [Pd(OAc)2] gives highest yields. Aryl bromides are coupled most efficiently using the DPEphos ligand. Chlorides are coupled using XPhos. The developed protocols are robust, versatile and easily reproducible on a large scale.

A Pd-catalyzed 1,3-difunctionalization of terminal alkenes using 1,1-disubstituted alkenyl nonaflates and arylboronic acid coupling partners is reported. This transformation affords allylic arene products that are difficult to selectively access using traditional Heck cross-coupling methodologies. The evaluation of seldom employed 1,1-disubstituted alkenyl nonaflate coupling partners led to the elucidation of subtle mechanistic features of π-allyl stabilized Pd-intermediates. Good stereo- and regioselectivity for the formation of 1,3-addition products can be accessed through a minimization of steric interactions that emanate from alkenyl nonaflate substitution.

A unique preference of tin(II) for aniline activation is disclosed. In the present work tin(II) triflate-catalyzed highly selective Markovnikov reductive hydroamination of internal as well as terminal alkynes is reported. The mechanistic study revealed the involvement of two steps in one pot wherein alkyne reduces to corresponding alkene in presence of PMHS as reducing agent followed by hydroamination of alkene. A broad range of alkynes transformed into tertiary amines with good to excellent yield. This method is equally applicable in synthesis of secondary amines.

A series of diarylpropenones is synthesized under microwave-assisted solvent-free conditions using FeCl3/bentonite as a stable acid catalyst system which can be reused several times without iron leaching.

A new approach for the synthesis of novel bis(imidazol-1-yl)vinyl-1,2,4-oxadiazoles has been developed. This method operates in a single step giving the products in good to excellent yields. Antiproliferative efficiency of the synthesized compounds was tested against HCT116 (colon cancer) and A549 (lung cancer) cell lines. Among them, compounds 3m (IC50, 9.7 μM) and 3h (IC50, 20.3 μM) were found to be the best antiproliferative agents.

Highly functionalized pyridin-2(1H)-one derivatives were synthesized in high yields by a sequential multicomponent reaction. The mechanism involves the Michael addition of Meldrum's acid to 3-formylchromone, followed by the addition of an amine, intramolecular amidation and elimination of acetone. Depending on the temperature used, decarboxylation can occur. The mechanism of this reaction has been proposed based on the by-products obtained when the reaction was performed using poorly reactive amines. The versatility of this approach has been exemplified using various 3-formylchromones and amines. Analogues of Meldrum's acid were also tested, allowing the synthesis of pyridin-2(1H)-one derivatives with various substituents on the aromatic ring.

Bovine serum albumin (BSA) catalyzed synthesis of dihydropyrano[2,3-c]pyrazole derivatives via a one pot, three component reaction of an aldehyde/ketone/isatin, malononitrile and 3-methyl-1H-pyrazol-5-(4H)-one in H2O–EtOH (7 : 3) at ambient temperature was developed in this work. The catalyst was found to work efficiently for aldehydes, ketones and isatins to give the corresponding dihydropyrano[2,3-c]pyrazole and spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives in high yields. BSA showed a broad range of catalytic promiscuity towards various aldehydes, aromatic/aliphatic ketones and substituted isatins. The use of an environmentally benign protocol, reusability of the catalyst, avoidance of hazardous solvents, excellent yields, easy work up and no byproduct formation make BSA an attractive candidate for further applications as a biocatalyst.

Two new compounds 1 and 2 have been isolated along with a known compound 3 from both Ficus pomifera Wall and Curcuma leucorrhiza Roxb. The compound 1 is a cyclopentane derivative, 5-(3,4,5,6-tetrahydroxyhexan-2ylidene)cyclopentane-1,2,3,4-tetraol; compound 2 is a natural polymer compound and compound 3 is β-sitosterol glucoside. The similarity of compound 1 has been studied by Reversed Phase-High Performance Liquid Chromatography (RP-HPLC). The compounds 2 and 3 have further been identified by comparison with spectral data. The compound 1 has been tested for anti-microbial and antioxidant activities. The isolation of compound 1, 2 and 3 have been reported from different plants of different families-Moraceae and Zingiberaceae for the first time.

A catalyst- and solvent-free protocol for the synthesis of 7-azagramine analogues is described via a three-component Mannich type reaction between 7-azaindole, aromatic aldehydes and heterocyclic amines in acceptable to excellent yields. Structures of the compounds were confirmed satisfactorily by 1 H NMR, IR, mass, TOCSY, HSQC and HMBC spectral analyses.

Aza-Michael reaction of ( E )-4-(diphenylphosphoryl)but-3-en-2-one with mono- and bicyclic nitrogen heterocycles proceeds regioselectively in the absence of catalysts to give the corresponding s-diphenylphosphoryl-b-azahetarylalkanones. Its reaction with imidazole in the presence of chiral organocatalysts affords the corresponding enantiomerically enriched adduct in higher yield.

Direct aerobic oxidative cross-dehydrogenative coupling of aryl acetaldehydes at C-3 position of imidazoheterocycles via copper catalyzed reaction resulted in the synthesis of dicarbonylated imidazoheterocycles in 55–85% yields. The methodology provides a straightforward, high yielding and one-pot approach towards the synthesis of C-3 dicarbonylated imidazoheterocycles without prior activation of C(sp2)-H or a base. This also reports the first method of coupling of aryl acetaldehydes on imidazo[1,2-a]pyridine system via double-oxidative cross-dehydogenative process.