Synthesis Of Hexahydroquinolines Research Articles

A Highly Efficient Strategy for One-Pot and Pseudo-Six-Component Synthesis of Hexahydroquinolines.

In this study, a homogeneous acid-catalyzed reaction of a series of benzaldehydes, benzylamines, and Meldrum's acid was presented, allowing the novel one-pot and multicomponent synthesis of hexahydroquinolines with high stereoselectivity. The current strategy has advantages including high regioselectivity, good efficiency, reasonable diversity, utilization of an inexpensive and safe catalyst, and easy purification of products by simple recrystallization. The current reaction utilizes 2 equiv of Meldrum's acid, 3 equiv of benzaldehyde derivatives, and one equiv of amine derivatives to yield (4'S,5'S,7'S)-1'-benzyl-2,2-dimethyl-4',5',7'-triphenyl-3',4',7',8'-tetrahydro-1'H-spiro[[1,3]dioxane-5,6'-quinoline]-2',4,6(5'H)-trione derivatives.

An application study of MnCoFe2O4@PEG-4000 (MCF@PEG-4000) MNPs as a catalyst in the synthesis of hexahydroquinolines and benzopyrans and as an nano-adsorbent for the removal of Cu (II) and Fe (III) ions in aqueous solutions

An application study of MnCoFe2O4@PEG-4000 (MCF@PEG-4000) MNPs as a catalyst in the synthesis of hexahydroquinolines and benzopyrans and as an nano-adsorbent for the removal of Cu (II) and Fe (III) ions in aqueous solutions

Synthesis of hexahydroquinolines, 5-amino-1,3-diphenyl-1h-pyrazole-4-carbonitrile and 1-aminoalkyl-2-naphthols derivatives using an engineered copper-based nano-magnetic catalyst (Fe3O4@CQD@Si(OEt)(CH2)3NH@CC@Ad@Cu(OAc)2)

In this project, a novel magnetic nano catalyst was used in solvent-free conditions in three different experimental fabrication sections, including the synthesis of hexahydroquinolines, 5-amino-1,3-diphenyl-1H-pyrazole-4-carbonitrile and 1-aminoalkyl-2-naphthols derivatives. Accordingly, in this study, a Carbon Quantum Dot (CQD)-based nanomagnetic catalyst (Fe3O4@CQD@Si(OEt)(CH2)3NH@CC@Ad@Cu(OAc)2) was synthesized, in which the Fe3O4 nanoparticles surface was protected using carbon quantum dots (CQDs) instead of conventional SiO2. The as-synthesized catalyst was characterized using different techniques, including Fourier transform infrared spectroscopy (FT-IR), X-ray powder Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Energy-Dispersive X-ray spectroscopy (EDX), EDX Elemental Mapping (EDX-Mapping), Thermal Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA), and Vibrating Sample Magnetometer (VSM). The activity of the as-synthesized catalyst was evaluated in the synthesis of hexahydroquinolines, 5-amino-1,3-diphenyl-1H-pyrazole-4-carbonitrile and 1-aminoalkyl-2-naphthols derivatives. The solvent-free condition with low reaction time and high reaction yield is the results of the prepared catalyst. Moreover, the effect of temperature and the amount of the catalyst (optimum reaction condition) were determined using a systematic approach, namely, the Design of Experiment (DoE). How the reaction was triggered by the catalyst was determined by FT-IR analysis.

Introduction of TiO2-[bip]-NH2+ C(NO2)3− as an effective nanocatalyst for the Hantzsch reactions

A novel reagent represented by TiO2-[bip]-NH2+ C(NO2)3− was synthesized, characterized and used as an efficient and reusable nanocatalyst in the synthesis of hexahydroquinoline and 1,8-dioxo-decahydroacridine derivatives.

Knoevenagel condensation versus Michael addition reaction in ionic-liquid-catalyzed synthesis of hexahydroquinoline: a SMD–DFT study

Knoevenagel condensation and Michael addition reaction are two different mechanisms for C–C bond formation. In this work, M06-2X method is used to compare activation free energies of Knoevenagel condensation and Michael addition reaction in the gas and ionic liquid phases. The role of 2-ethyl imidazolium hydrogen sulfate in the synthesis of hexahydroquinolines is investigated. To model ionic liquid phase, SMD continuum universal solvation model is used. Data show that Knoevenagel condensation and Michael addition have activation free energies of 45 and 13 kcal mol−1 in the gas phase and + 24 and + 12 kcal mol−1 in the ionic solution phase, respectively. The final cyclization process has zero barrier energy. Analyzing TS structures by the quantum theory of atoms in molecules (QTAIM) show that the TS structure of Knoevenagel step is similar to the product, while the TS structure of Michael addition step is similar to the reactants.

Sulfamic Acid‐functionalized Nano‐titanium dioxide as a Novel and Highly Efficient Heterogeneous Nanocatalyst for One‐pot and Solvent‐free Synthesis of Hexahydroquinolines

Hexahydroquinolines are synthesized via one‐pot, four‐component condensation of 1,3‐cyclic diketones, aromatic aldehydes, malononitrile, and ammonium acetate in the presence of sulfamic acid‐functionalized nano‐titanium dioxide as a novel type of heterogeneous nanocatalyst. The optimized reaction condition is achieved using response surface method (Box–Behnken design [BBD]). Operational simplicity, low cost, nontoxic nature, and high reusability of the catalyst together with simple work‐up and excellent product yields are the main advantages of this methodology. Also, the nanocatalyst can be recovered easily by centrifugation and reused efficiently for at least seven consecutive runs.

ChemInform Abstract: Synthesis of Hexahydroquinoline (HHQ) Derivatives Using ZrOCl2·8H2O as a Potential Green Catalyst and Optimization of Reaction Conditions Using Design of Experiment (DOE).

In this investigation, hexahydroquinoline (HHQ) derivatives were synthesized via a one-pot reaction using dimedone, β-ketoester, ammonium acetate, and different aryl aldehydes. ZrOCl2·8H2O was used as a potential green catalyst, it is a commercially available solid material, with low toxicity, low cost and high activity, and it is easy to handle. The reaction conditions were optimized using response surface methodology (Central Composite Design (CCD)) with three replicates at a central point. Optimization showed that the optimum reaction temperature and amount of catalyst are 83.75 °C and 0.15 mol%, respectively. The lower reaction yields at temperatures higher than 83.75 °C are related to the formation of a new crystalline phase of ZrOCl2·8H2O. The fitted quadratic polynomial model applied to the experimental yield could well predict the experimental reaction yield. Ecofriendly reaction conditions, easy workup procedure, the reusability of the catalyst, short reaction times and high yields are some of the advantages of this work.

Design, characterization and application of silica-bonded imidazolium-sulfonic acid chloride as a novel, active and efficient nanostructured catalyst in the synthesis of hexahydroquinolines

A novel nanostructured catalyst namely silica-bonded imidazolium-sulfonic acid chloride (SBISAC) was prepared, and fully characterized by several techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX). The nano-compound was applied as an efficient and heterogeneous catalyst in the synthesis of hexahydroquinolines via the one-pot multi-component condensation of arylaldehydes with dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters and ammonium acetate under mild and solvent-free conditions.

Synthesis of hexahydroquinoline (HHQ) derivatives using ZrOCl2·8H2O as a potential green catalyst and optimization of reaction conditions using design of experiment (DOE)

In this investigation, hexahydroquinoline (HHQ) derivatives were synthesizedviaa one-pot reaction using dimedone, β-ketoester, ammonium acetate, and different aryl aldehydes.

Synthesis of hexahydroquinolines using the new ionic liquid sulfonic acid functionalized pyridinium chloride as a catalyst

Sulfonic acid functionalized pyridinium chloride [pyridine-SO3H]Cl has been synthesized as a novel Brönsted acidic ionic liquid and characterized on the basis of its FT-IR, 1H and 13C NMR, MS, thermogravimetry, and derivative thermogravimetry data. The material has also been used as a highly efficient, homogeneous, and reusable catalyst for the preparation of hexahydroquinolines according to the one-pot multi-component condensation of arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters, and ammonium acetate under solvent-free conditions.

ChemInform Abstract: One‐Pot Synthesis of Hexahydroquinolines via Hantzsch Four‐Component Reaction Catalyzed by a Cheap Amino Alcohol.

AbstractThe advantages of the presented method are the simple experimental procedure, mild conditions, lowcost, and excellent yields.

One-Pot Synthesis of Hexahydroquinolines via Hantzsch Four-Component Reaction Catalyzed by a Cheap Amino Alcohol

An economic, efficient access to hexahydroquinolines was found. In the presence of threo-(1S,2S)-2-amino-1-(4′-nitrophenyl)-1,3-propanediol, a waste product formed in the production of chloromycetin, a one-pot, four-component Hantzsch reaction of dimedone, aldehydes, ethyl acetoacetate, and ammonium acetate at room temperature furnished hexahydroquinoline derivatives in excellent yield. A possible catalytic mechanism was also suggested.

One‐Pot Synthesis of Hexahydroquinolines via a Four‐Component Cyclocondensation under Microwave Irradiation in Solvent Free Conditions: A Green Chemistry Strategy.

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Competitive reactions of β-dicarbonyl and β-aminovinylcarbonyl compounds with aldehydes in the synthesis of hexahydroquinolines

Competitive reactions of β-dicarbonyl and β-aminovinylcarbonyl compounds with aldehydes in the synthesis of hexahydroquinolines

Competitive reactions of β-dicarbonyl and β-aminovinylcarbonyl compounds with aldehydes in the synthesis of hexahydroquinolines

It was established that the previously found regularity in the formation of unsymmetrical 5-oxo-2,7,7-trimethyl-4-R'-3-R-1,4,5,6,7,8-hexahydroquinolines or symmetrical 3,3,6,6-tetramethyl-9-R'-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-diones from β-dicarbonyl and β-aminovinylcarbonyl compounds and an aldehyde, depending on the conditions, is also valid for acetylacetone and benzoylacetone. The competitive character of β-dicarbonyl and β-aminovinylcarbonyl compounds in the reaction was established. The order of formation of the hexahydroquinolines was determined.