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A Ru-catalyzed acceptorless dehydrogenative multicomponent reaction has been developed. This reaction offers a cost-effective and simple operational strategy to synthesize biologically active 1,8-dioxodecahydroacridine derivatives. The protocol provides a wide range of substrate scope and various functional groups are also well tolerated under the reaction condition. To shed light on the mechanistic and kinetic study, some controlled experiments and deuterium labeling experiments were executed. A time-dependent product distribution experiment is also presented and the reaction scale-up is performed to highlight the practical utility of this strategy.

Diminution of oxidative stress-mediated diseases is an essential pharmaceutical objective in modern biomedical research. The present work stresses upon the efficient and eco-friendly synthesis of an array of novel diversely functionalized pyrrole derivatives which are found to be antioxidants with reactive oxygen species (ROS) shielding competency against the deleterious consequence of oxidative stress. The results of the investigation displayed the effect of structural modification of the pyrrole derivatives on their respective antioxidant properties to various ROS. Noteworthy, the pyrrole moiety bearing 4-hydroxycoumarin or 2-hydroxy-1,4-naphthoquinone as substituent showed outstanding defensive potency towards [rad]OH and O2 [rad] ? while, nitrogen atom linked with aliphatic side-chain in the pyrrole scaffold made a strong affirmative impression in DPPH[rad] scavenging assay. More interestingly, an influencing reducing power was observed in pyrrole derivatives carrying cyclohexane 1,3-dione as one of the substituents. To have a comprehensive acuteness into the antioxidant capacity of the synthesized pyrrole derivatives against Trolox as a standard antioxidant, a crucial approach was taken into account by calculating TEAC (Trolox Equivalent Antioxidant Capacity) in case of [rad]OH and DPPH[rad] scavenging activity.

A one-pot, clean and green procedure is described for the syntheses of new azocine derivativesviaaddition reactions of enaminones with acenaphthoquinone followed by periodic acid-mediated oxidative cleavages of the corresponding vicinal diols. Various derivatives of azocine were prepared and well characterized. The excellent yields, simple synthesis procedure, lack of a need to carry out any tedious work-up and column chromatography, metal-free catalysis, and mild reaction conditions are important features of this protocol.

A novel magnetic SrFeGO nanocatalyst (NC) was synthesized through a simple sol–gel technique by introducing strontium and iron oxide nanoparticles onto graphene. The synthesized NC was characterized using FT-IR and FE-SEM. Subsequently, the catalytic activity of SrFeGO was tested in a reaction between β-dicarbonyl compounds and aniline derivatives to gain β-enamino ketone derivatives under solvent-free conditions. It was found that SrFeGO NC is a potential catalyst for the synthesis of β-enamino ketones. The β-enamino ketone produced by such reactions could be isolated in high purity without the need for chromatographic purifications. The newly prepared magnetic graphene oxide nanocomposite could be recovered and reused for numerous times with no significant decrease in efficiency. Moreover, the protocol has the advantages of excellent yielding (up to 98%) in short a reaction time, benefitting an easy workup procedure and being environmentally friendly.

Abstract: β-Enaminone and its derivatives have emerged among the finest bioactive intermediates. High yields of several β-enaminones (86–97%) are achieved through treatment of substituted aromatic and aliphatic amines with cyclic/acyclic 1,3-diketones, over the magnetically separable cobalt ferrite nanoparticles (CoFe2O4 NPs). The latter was prepared upon co-precipitation. Its purity, fine crystallinity, elemental distributions, morphology, magnetic features, and thermal stability were confirmed by Fourier transform infrared, X-ray diffraction, energy dispersive X-ray spectrometry, scanning electron microscopy, vibrating sample magnetometry, and thermal gravimetric analysis analyses. Thus, CoFe2O4 NPs acted as an excellent green heterogeneous nanocatalyst for synthesis of β-enaminones and gave good recyclability, while showing insignificant loss of their activity. Graphical Abstract: [Figure not available: see fulltext.].

A simple and efficient one-pot synthesis of tetrahydroacenaphtho[1,2-b]indolone derivatives via four-component reaction of 5,5-dimethylcyclohexane-1,3-dione (dimedone), arylamines, acenaphthoquinone, and active methylene compounds under catalyst-free conditions is described. The reactions were carried out under mild conditions using ethanol as solvent. Advantages of this method include simple experimental and workup procedure, readily available starting materials, and high yields.

A fast, mechanochemical and solvent-free synthesis of substituted tetrahydropyrimidines and octahydroquinazolines under Au(III)-catalysis has been developed. The practical feasibility, eco-friendliness and operational simplicity of this chemistry is exemplified by ball milling three components such as formaldehyde, amines and 2-butynedioates/dimedone in a shaker mill for as little as five minutes, thus avoiding the requirement of undesirable solvents and long reaction times. Moreover, this protocol furnishes the target compounds in high yields without any side products and in some cases offers products with excellent regioselectivity. Out of the 26 compounds screened for anticonvulsant potency, 11 compounds exhibited comparable activity against a standard drug.

Dimedone enamines were applied for the first time as new dienophiles in hetero-Diels-Alder reactions with inverse electron demand. Cycloadditions of barbituric acid 5-ylidene alditols with dimedone enamines were performed in dichloromethane at room temperature for 3 days and fused uracils-chromeno[2,3-d]pyrimidine-2,4-diones were obtained in good 73-87% yields. Only one enantiomerically pure stereoisomer was obtained in each studied cycloaddition. Analysis of 1H NMR and 2D NMR spectra allowed for the determination that cycloadducts exist in solution as mixture of the neutral form and dipolar ion. The prepared fused uracils contain both amine and enol functional groups, so share amphiprotic properties and they are zwitterions in solid state. The new class of compounds-amino enols was synthesized, which similarly to amino acids exists as zwitterions. In obtained cycloadducts amino groups and sugar moieties are close each other and they both are in cis configuration and in axial position. It was also shown that different alkenes can be used as dienophiles towards barbituric acid 5-ylidene alditols, for example, styrene or 1-amino-2-thiocarbamoyl-cyclopent-1-ene.

A highly regiospecific synthesis of a series of indenoindoles is reported, together with X-ray studies and their activity against human prostate cancer cells PC-3 and LNCaP in vitro. The most effective compound 7,7-dimethyl-5-[(3,4-dichlorophenyl)]-(4bRS,9bRS)-dihydroxy-4b,5,6,7,8,9bhexahydro-indeno[1,2-b]indole-9,10-dione 7q reduced the viability in both cell lines in a time and dose-dependent manner. Inhibitory effects were also observed on the adhesion, migration, and invasion of the prostate cancer cells as well as on clonogenic possibly by inhibition of MMP-9 activity. Molecular docking of 7q and 6k into MMP-9 human active site was also performed to determine the probable binding mode.

An efficient, inexpensive, environmentally friendly and high yield one-pot route to new spiro[indolo-3,10′-indeno [1,2-b]quinolin]-trione derivatives has been developed, involving three-component reaction of enaminones, N-substituted isatins and Indane-1,3-dione catalyzed by FeCl3. The approach to this spiro-heterocycle is noteworthy because it results in the formation of three new σ (two C-C and one C-N) bonds in a single operation, leading to the construction of novel spiro skeleton. This method works on a large scale in excellent yields.

Synthesis of KCC-1 silica sulphuric acid as a new catalyst has been reported. The catalyst was characterized using XRD, SEM, TEM, BET, FT-IR, TGA-DTA, and EDX analysis. The catalytic activity was evaluated for the synthesis of enaminones under solvent-free conditions. The catalyst was easily recovered and reused up to seven cycles with slight loss of activity. The attractive features of this protocol are low amount of catalyst loading, short reaction time, mild reaction conditions, good to excellent yield of the products, easy handling of the catalyst and simple operational procedure. Graphical Abstract: [InlineMediaObject not available: see fulltext.]A highly efficient Sulphated nanosilica sulphuric acid has been synthesized and applied for the synthesis of enaminones. This catalytic protocol is better for the synthesis of enaminone than previously reported procedures in terms of catalyst loading, reaction condition, reaction time and yields of the products.

A new category of polyhydroquinoline derivatives 8a-t were synthesized in moderate to good yield (64-85%) by one-pot three-component cyclocondensation reaction of 5-(1H-imidazol-1-yl)-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde 3 with various enaminones

An efficient method has been developed for the synthesis of β-enaminones under solvent-free reaction conditions using PPA-SiO2 as catalyst. The reaction yields were good to excellent (up to 90%). This methodology affords high selectivity and good tolerance of a variety of different functional groups present on both aromatic and aliphatic amines. In addition, the methodology is environmentally benign and cost-effective due to absence of solvent and easy work-up.

The present invention relates to compounds having the general Formula I: which absorb UV radiations and protect biological materials as well as non-biological materials from damaging exposure to UV radiations. The present invention also relates to formulations and compositions comprising such compounds for use in absorbing UV radiations and in protecting biological materials as well as non-biological materials against UV radiations.

A series of β-substituted enaminones were prepared through the one-pot reaction of β-dicarbonyl compounds with various amines in the presence of silica ferric hydrogensulfate under solvent free conditions at room temperature. The reactions proceed smoothl

Silica sulfuric acid, a heterogeneous reagent, has been found to be an efficient catalyst for the synthesis of β-enaminones and β-enaminoesters under microwave irradiation in a microwave reactor within 2 min. The experimental procedure is simple and environment-friendly, and results in excellent yields of the products. Further, the catalyst is recyclable, and the reaction is 60 times faster than the reaction at room temperature. Copyright Taylor & Francis Group, LLC.

Molecular iodine has been found to be an efficient and ecofriendly catalyst for the synthesis of β-enaminones from dimedone and amines at room temperature in the presence of acetonitrile within 60 min. The experimental procedure is simple, includes shorter reaction times, and results in excellent yields of the products. Copyright

Several β-enaminones and β-enaminoesters have been synthesized in high yields from amine and β-diketone in the presence of Zeolite (ZSM-5) as a catalyst. This method is applicable to both cyclic and acyclic ketones with aromatic and aliphatic amines. Copyright E-Journal of Chemistry 2004-2011.

(Chemical Equation Presented) A green and convenient approach to the synthesis of β-enaminones from aromatic amines and 5-substituted-1,3- cyclohexanedione in the presence of dilute hydrochloric acid (30 mmol=L) as a catalyst in solvent-free media is described. This method provides several advantages such as environmental friendliness, low cost, good yields, and simple workup procedure. Copyright Taylor & Francis Group, LLC.

Silica sulfuric acid is utilized as a green, highly efficient, heterogeneous and recyclable catalyst for the preparation of β-enaminones and β -enamino esters from amines and β -dicarbonyl compounds under solvent-free conditions at 80 °C. Using this method, the title compounds are produced in high to excellent yields and in short reaction times.

A highly efficient, simple and green procedure for the synthesis of β-enaminones and β-enamino esters is described. The reaction of aromatic and aliphatic amines with β-dicarbonyl compounds using catalytic amount of silica-supported LiHSO4 (LiHSO4/SiO2) under solvent-free conditions at 80 °C affords the title compounds in high to excellent yields and in short reaction times.

An efficient and simplified protocol for NaHSO4/SiO2 catalyzed solvent-free synthesis of β-enaminone and 2-methylquinolin-4(1H)- one derivatives under microwave irradiation is described. A series of functionalized derivatives have been synthesized in shorter reaction times with moderate to good yields. The use of milder catalyst in non-conventional method offers significant advantages over conventional methods, such as higher selectivities, simplicity, solvent-free reaction and non-environmental polluting conditions.

An improved method for the synthesis of carbazolones via the condensation of arylamines with 1,3-cyclodiketones followed by intramolecular oxidative cyclization catalyzed by palladium acetate and copper acetate in ethanol under an oxygen atmosphere was established. The improved method has the advantage of easily available starting materials and affords good yields.

P2O5/SiO2 (30% w/w) was applied as an efficient, heterogeneous, and reusable catalyst for the synthesis of β-enaminones. The reactions were rapidly completed at 80°C under solvent-free conditions and products were obtained in good to excellent yields. Copyright Taylor & Francis Group, LLC.

A facile amination of solid 1,3-dicarbonyl compounds with ammonium salts or amines in solid state has been achieved by mechanochemical grinding in the presence of KHSO4 and SiO2. Most of the reactions proceed smoothly at room temperature under solid-state conditions and give their corresponding β-imino derivatives in high yields. The method has the advantage of simple manipulation and mild conditions. Georg Thieme Verlag Stuttgart.

β-Enaminones have been synthesized in good yield from 1,3-dicarbonyl compounds and activated amines in the presence of ceric ammonium nitrate as catalyst.

β-Enamino ketones have been synthesized in excellent yield by the reaction of aromatic or aliphatic amines with 1,3-dicarbonyl compounds in polyethylene glycol (PEG)-600water. The PEG-600 is recycled and reused. CSIRO 2008.

Condensations of 1-phenyl-2,2,2-trifluoro-1-chloroethyl isocyanate and 1-chlorobenzyl isocyanate with cyclic 1,3-diketones yield respectively carbofused 2,3-dihydro-1,3-oxazin-4-ones and 3,4-dihydro-1,3-oxazin-2-ones.

β-Enamino ketones have been synthesised in excellent yield at room temperature in the absence of any added catalyst by the reaction of aromatic or aliphatic amines with 1,3-dicarbonyl compounds in ionic liquid. The ionic liquid is recycled and reused several times. Georg Thieme Verlag Stuttgart.

Numerous reaction types in the field of iminium salts are performed in the gas-solid and solid-solid techniques in order to reach 100% yield. The stoichiometric runs are waste-free and do not require costly workup. Frequently, iminium salts were avoided, as acid catalysis was dispensable. Thioureas and α-halogenated ketones give a variety of 2-aminothiazoles via thiuronium salts in quantitative yield. A new intramolecular solid-state thermal condensation is reported. Enaminoketones are synthesized quantitatively from anilines and 1,3-diketones without catalysis and those can be used for quantitative solid-state 4-cascade reactions. Solid paraformaldehyde is used to produce methylene imines and internally trapped methylene iminium salts. Benzoylhydrazones are produced again without catalysis in the solid state. Vacuum and ball-mill techniques are particularly useful in the production of highly sensitive iminium salts. Hexahydro-1,3,5-triazines cyclorevert upon exposure to HCl gas to give solid arylmethylene iminium chlorides as new versatile reagents. These are used in arylaminomethylations of β-naphthol and of themselves to give Troeger's bases in 3-cascades. More direct are 4-cascade Troeger's base syntheses by dissolving hexahydro-1,3,5-triaryltriazines in trifluoroacetic acid. Alkylations of imines with trimethyloxonium tetrafluoroborate and triphenylmethyl cation give highly sensitive quaternary iminium salts in the ball-mill. The products are characterized by spectroscopic techniques and density functional theory (DFT) calculations at the B3LYP 6-31G* level. Molecular movements in the crystal and surface passivation are investigated with atomic force microscopy (AFM) techniques.

Described herein is the first example of the palladium-catalyzed coupling of vinylogous amides with aryl bromides and chlorides. The scope of this reaction with respect to the aryl component is investigated. Additionally, a tandem reaction sequence in which the above coupling is followed by an intramolecular Heck reaction is presented. These reactions can be applied to high-yielding, one-pot syntheses of nitrogen-containing heterocycles.

This report continues the in-depth evaluation of methyl 4--6-methyl-2-oxocyclohex-3-en-1-oate, 1 (ADD 196022), and methyl 4-(benzylamino)-6-methyl-2-oxocyclohex-3-en-1-oate, 2, two potent anticonvulsant enaminones.These compounds were evaluated employing the amygdala kindling model.Neither 1 nor 2 was active against amygdala kindled seizures, further supporting the corneal kindled model as a definitive tool for antielectroshock seizure evaluation as previously reported.Additional intraperitoneal (ip) data on 1 revealed toxicity at 24 h at 100 mg/kg.Several active analogs have been prepared with the view to minimizing toxicity.In a special ip rat screen developed by the Antiepileptic Drug Development (ADD) Program, these newer analogs were evaluated for protection against maximal electroshock seizures (MES) at 10 mg/kg and neurotoxicity at 100 mg/kg.From this screen, several compounds were shown to be safer alternatives, the most notable was methyl 4--6-methyl-2-oxocyclohex-3-en-1-oate, 13.Compound 13 had an ip ED50 of 4 mg/kg in the rat and a TD50 of 269 mg/kg, providing a protective index (TD50/ED50) of > 67.By variation in the ring size, additional aromatic substitutions and the synthesis of acyclic analogs, these newer compounds provide a more definitive insight into the structure-activity correlation.CLOGP evaluation and molecular modeling studies are also provided to further elaborate the molecular characteristics of potential anticonvulsant enaminones.