Facile Three-step Synthesis Research Articles

Synthesis of MoS2@NdS heterostructures featuring augmented field emission performance

A molybdenum disulfide and neodymium sulfide (MoS2–NdS) heterostructure was successfully fabricated through a facile three-step synthesis process using the spin coating technique exhibiting remarkable field emission properties.

Synthesis of Selenium-Based Small Molecules Inspired by CNS-Targeting Psychotropic Drugs and Mediators

Due to its endogenously high oxygen consumption, the central nervous system (CNS) is vulnerable to oxidative stress conditions. Notably, the activity of several CNS-targeting compounds, such as antidepressant and hypnotic drugs, or endogenous mediators, such as melatonin, is indeed linked to their ability of mitigating oxidative stress. In this work, we report the synthesis of two organoselenium compounds of which the structure was inspired by CNS-targeting psychotropic drugs (zolpidem and fluoxetine) and an endogenous mediator (melatonin). The molecules were designed with the aim of combining the ROS-scavenging properties, which were already assessed for the parent compounds, with a secondary antioxidant action, a glutathione peroxidase (GPx) mimic role empowered by the presence of selenium. The compounds were obtained through a facile three-step synthesis and were predicted by computational tools to passively permeate through the blood–brain barrier and to efficiently bind to the GABA A receptor, the macromolecular target of zolpidem. Of note, the designed synthetic pathway enables the production of several other derivatives through minor modifications of the scheme, paving the way for structure–activity relationship studies.

Tailored synthesis of hybrid iron-nitrogen-graphene with reduced carbon xerogel as an efficient electrocatalyst towards oxygen reduction

In this study, a non-precious metal-based electrocatalyst consisting of nitrogen-doped iron-coated reduced graphene oxide (FeNG) on carbon xerogel towards oxygen reduction reaction (ORR) in alkaline media is reported. Herein, we describe a facile three-step synthesis route towards enhanced ORR activity. The effect of pyrolysis temperature and the resulting structural variations of the designated catalyst towards ORR were investigated. The as-synthesized carbon xerogel samples were reduced (rCX) and then pyrolyzed at different temperatures, viz., 700, 900, and 1100 °C, followed by the incorporation of FeNG, and their performance towards ORR was studied. The resultant rCXFeNG (reduced carbon xerogel-iron-nitrogen-doped graphene) catalyst pyrolyzed at an optimum temperature of 1100 °C (rCXFeNG-1100) showed enhanced electrocatalytic performance towards ORR and exhibited an onset potential of 0.84 V vs. RHE (reversible hydrogen electrode). Besides, it is remarkable that rCXFeNG-1100 delivers a limiting current density of 5.55 mA cm−2, which is fairly equivalent to that of the commercial Pt/C electrocatalyst. It is noteworthy that the rCXFeNG-1100 electrocatalyst showed a four-electron transfer pathway for ORR and showed better stability and improved durability outperforming the commercial Pt/C electrocatalyst. The present study opens up a promising approach for the design and fabrication of cost-effective non-precious ORR electrocatalysts for alkaline polymer electrolyte fuel cells.

Development and optimization of a thiol imidazolium-based ionic liquid for ultrasonic assisted liquid-liquid microextraction combined with HPLC-FLD for determination of bisphenols in milk and juice samples

Herein, a novel thiol imidazolium-based ionic liquid [C4MIM-SH]Br was synthesized by a facile three-step synthesis method, and its molecular structure was characterized by infrared (IR) spectra, 1H nuclear magnetic resonance (NMR) and mass spectrometry (MS). In addition to its merits as an ionic liquid, [C4MIM-SH]Br has strong acidity and high hydrophilicity. By integrating a conventional extractant ([CnMIM]PF6) with [C4MIM-SH]Br as a disperser, a whole ionic liquid microextraction was developed for determination of bisphenols (BPs). The main factors influencing extraction efficiency were optimized by Plackett-Burman design (PBD), single factor screening and central composite design as follows: 78 μL [C6MIM]PF6 as extraction solvent, 81 μL [C4MIM-SH]Br as disperser, 7 min ultrasound time, 13.5 min cooling time and 3min centrifugation time at 4000 rpm. Under optimized conditions, this method gave limit of detection for bisphenols in range of 0.13–0.82 μg L−1 in milk and juices, relative recoveries of 91.6–107.9%. Advantages of using [C4MIM-SH]Br as an independent disperser include avoiding an extra pH adjustment step, producing a rapid and clear layering phenomenon leading to convenient separation, and providing lower detection limits and higher extraction recoveries. Due to its multi-functions, [C4MIM-SH]Br has widespread application prospects in food analytical fields.

Synergetic influence of Au/Cu2O core-shells nanoparticle on optical, photo-electrochemical, and catalytic activities of Au/Cu2O/TiO2 nanocomposite

Au/Cu2O/TiO2 core-shell nanorods are successfully synthesized using a facile three-step chemical synthesis technique. The Au nanoparticles core of Au/Cu2O performed as the catalytic activity enhancer, the Cu2O shell acts as a co-catalyst. The Au/Cu2O/TiO2 nanorods show higher photocatalytic performance, excellent recyclability, and stability during the degradation of organic pollutants when compared to pristine TiO2 and Au/TiO2 nanorods, under solar light irradiation. The suitable p-n junction at the interface of Cu2O shell and the TiO2 nanorods contributes to the enhanced catalytic activity. The photo-electrochemical characteristics and the possible catalytic mechanism of Au/Cu2O/TiO2 nanorods under solar light irradiation are also investigated.

Facile three-step synthesis and photophysical properties of [8]-, [9]-, and [12]cyclo-1,4-naphthalene nanorings via platinum-mediated reductive elimination.

Herein we report a facile three-step synthesis of [8]-, [9]-, and [12]cyclo-1,4-naphthalene nanorings as the conjugated segments of carbon nanotubes. The nanorings were created via a platinum-mediated assembly of 1,4-naphthalene-based units and subsequent reductive elimination in the presence of triphenylphosphine. This present platinum-mediated approach is attractive because of its simple three-step process to produce the targeted nanorings in a high overall yield. In addition, their photophysical properties were studied using UV-vis spectroscopy and photoluminescence (PL) spectroscopy, which further revealed their unique size-dependent properties.

A general three-step one-pot synthesis of novel (E)-6-chloro-2-(aryl/hetarylvinyl)quinoline-3-carboxylic acids.

In this work, a facile and general three-step one-pot synthesis of structurally new (E)-6-chloro-2-(aryl/hetarylvinyl)quinoline-3-carboxylic acid derivatives has been achieved from easily available ethyl 6-chloro-2-(chloromethyl) quinoline-3-carboxylate and aromatic or heteroaromatic aldehydes. This strategy features simple one-pot operation, tolerance of a wide range of substituents, and good yields. Moreover, these newly synthesized compounds belong to a new class of quinoline derivatives and could be good candidates for the development of more complex quinoline compounds for use in medicinal chemistry.

Three-step synthesis of 2,5,7-trisubstituted indoles from N-acetyl-2,4,6-trichloroaniline using Pd-catalyzed site-selective cross-coupling.

We report a facile three-step synthesis of 2,5,7-trisubstituted indoles from N-acetyl-2,4,6-trichloroaniline, with the first step featuring Pd/dihydroxyterphenylphosphine (DHTP)-catalyzed ortho-selective Sonogashira coupling followed by cyclization to afford 2-substituted 5,7-dichloroindoles. Subsequent introduction of aryl or alkenyl groups at the C7 position was achieved by Pd/DHTP-catalyzed site-selective Kumada-Tamao-Corriu coupling, with further substitution of the chlorine at the C5 position (Suzuki-Miyaura coupling or Buchwald-Hartwig amination) affording 2,5,7-trisubstituted indoles.

A facile three-step total synthesis of tanshinone I

A facile synthetic approach for total synthesis of tanshinone I has been accomplished. The key precursor is a novel compound, epoxy phenanthraquinone. And this synthesis of tanshinone I is achieved in only three simple stages, which include Diels–Alder reaction, Δ2-Weitz–Scheffer-type epoxidation, and Feist–Bénary reaction from commercially available styrene.

Covalently-Functionalized Graphene for Supercapacitor Application

Due to the power requirements for electric vehicles, tremendous work has been devoted to energy storage devices with high power density, energy density, and rate performance. Electrochemical supercapacitors are very attractive because of their better cycling performance and higher power density as compared to Lithium-ion batteries.1 Carbon materials have been considered as promising materials as supercapacitors due to their high surface area, excellent electrical conductivity, and good stability.2 The double-layer capacitance of a carbon supercapacitor is proportional to the surface area of its electrode material accessible by the electrolyte ions.3 However, commercial supercapacitors based on activated carbon electrodes only deliver an specific capacitance of about 100 F/g, which is significantly lower than that of Li-ion batteries.4 Therefore, preparing materials with high surface area and suitable pore size distribution is very critical in achieve high-performance supercapacitors. Recently, graphene, a two-dimensional single-atom-thick layer of sp2-bonded carbon, has drawn much attention due to its exotic properties, such as high surface area, electric conductivity, and mechanical strength.5 These properties make graphene a very promising candidate for supercapacitor application.6 However, due to the strong van de Waals force between neighboring layers, graphene sheets are inclined to restack into aggregates a few layers thick, resulting in a large decrease in the surface area. Here, we report facile fabrication of covalently-functionalized graphene as supercapacitor electrodes. One example is covalently-grafted polyaniline on graphene oxide, and the other example is phenylbenzimidazole-functionalized graphene. A facile three-step synthesis to prepare covalently-grafted PANI/GO nanocomposites at room temperatures. The covalently-grafted composites formed a uniform hierarchical morphology of nanorod-like PANI grown on planar GO sheets, in contrast to a nonuniform morphology of nongrafted composites. The covalently-grafted PANI/GO composites exhibited higher surface area and larger pore volume compared with PANI and and noncovalently-grafted PANI/GO composites. These features allow the increased exposure of PANI to the electrolyte ions, resulting in a more accessible PANI surface for redox reaction species and faster ion transport. The covalently-grafted PANI/GO composites prepared with an aniline/GO ratio of 6:1 showed the highest capacitance of 422 F/g at a current density of 1 A/g. The capacitance can be retained at about 83% after 2000 cycles at 2 A/g. The excellent electrochemical performance can be attributed to the maximized synergistic effect between GO and PANI in the PANI/GO composites prepared via this covalent grafting approach. Phenylbenzimidazole covalently-functionalized graphene was prepared by hyderthermal treatment of benzoic acid-functionalized graphene oxide and o-phenyldiamine in a teflon-lined autoclave for 16 h at 160 °C. Difference from pristine graphene oxide, carboxyl groups are present on both edge and basel plane of graphene oxide sheets in the benzoic acid-functionalized graphene oxide, which was prepared from diazonium reaction. The phenylbenzimidazole group can effectively act as the spacers to partially prevent the restacking/aggregation of the graphene sheets. The phenylbenzimidazole groups are also electrochemical active and can contribute to psedocapacitance. When used as supercapacitor electrodes, the functionalized graphene materials exhibit much better electrochemical performances (more than twice as much capacitance) than pure graphene, implying their potential for energy storage applications. Figure 1. (a) CV curves of polyaniline and and covalently-grafted PANI/GO composites in 1 M H2SO4 at a scan rate of 10 mV/s; (b) CV curves of graphene and and Phenylbenzimidazole covalently-functionalized graphene in 1 M Na2SO4at a scan rate of 10 mV/s. Reference 1. Conway, B. E., Electrochemical Supercapacitors: Scientific Fundamentals and Technological Applications. Springer: 1999. 2. Zhang, L. L.; Zhao, X. S., Chemical Society Reviews 2009, 38(9), 2520-2531. 3. Wang, L.; Fujita, M.; Inagaki, M., Electrochimica Acta 2006, 51(19), 4096-4102. 4. Pandolfo, A. G.; Hollenkamp, A. F., Journal of Power Sources 2006, 157(1), 11-27. 5. Allen, M. J.; Tung, V. C.; Kaner, R. B., Chemical Reviews 2009, 110(1), 132-145. 6. Stoller, M. D.; Park, S.; Zhu, Y.; An, J.; Ruoff, R. S., Nano Letters 2008, 8 (10), 3498-3502. Figure 1

Ultraviolet Photodetector Fabricated from 3D WO3 Nanowires/Reduced Graphene Oxide Composite Material

ABSTRACTAn Ultraviolet (UV) photodetector with high responsivity and relative fast response speed was fabricated from three dimensional WO3 nanowires/reduced graphene oxide (3D WO3 NWs/RGO) composite materials. The 3D WO3 NDs/GN composite was synthesized using a facile three-step synthesis. First, the Na2WO4/Graphene Oxide (GO) precursor was synthesized by homogeneous precipitation. Second, the Na2WO4/GO precursor was transformed into H2WO4/GO composites by acidification. Finally, the H2WO4/GO composites were reduced to 3D WO3 NWs/RGO via hydrothermal reduction process. A maximum photoresponsivity of 4.2 A/W at 374 nm was observed under 20 V bias. The UV photodetector showed relative fast transient response, which is at least 2 orders of magnitude faster than UV photodetectors fabricated from WO3 nanowires. The good photoresponsivity and fast transient response are attributed to improved carrier transport and collection efficiency through graphene.

An ultraviolet photodetector fabricated from WO3 nanodiscs/reduced graphene oxide composite material

A high sensitivity, fast ultraviolet (UV) photodetector was fabricated from WO3 nanodiscs (NDs)/reduced graphene oxide (RGO) composite material. The WO3 NDs/reduced GO composite material was synthesized using a facile three-step synthesis procedure. First, the Na2WO4/GO precursor was synthesized by homogeneous precipitation. Second, the Na2WO4/GO precursor was transformed into H2WO4/GO composites by acidification. Finally, the H2WO4/GO composites were reduced to WO3 NDs/RGO via a hydrothermal reduction process. The UV photodetector showed a fast transient response and high responsivity, which are attributed to the improved carrier transport and collection efficiency through graphene. The excellent material properties of the WO3 NDs/RGO composite demonstrated in this work may open up new possibilities for using WO3 NDs/RGO for future optoelectronic applications.

Synthesis and photocatalytic application of Au/Ag nanoparticle-sensitized ZnO films

Here it is demonstrated that the Au–Ag-ZnO architecture can be immobilized on indium tin oxide (ITO) substrate through a facile three-step synthesis approach. A series of ZnO films with different modifications of Au and Ag were applied to study the effect of Ag and Au nanoparticles on the morphology, optical properties and photocatalytic activity. An annealing treatment of the ZnO nanosheets before Ag–Au deposition is found to play an important role in the properties of the Au–Ag-deposited ZnO nanosheet (Au–Ag-ZnO). The annealing treatment results in a significant increase in the surface area of ZnO, and consequently an increase in the depositing amount of Ag nanoparticles. The Au–Ag-ZnO film shows nearly twice the photocatalytic efficiency than pure ZnO, and much higher efficiency comparing with the Ag-ZnO film in the photocatalytic degradation of methyl orange (MO) under UV illumination in aqueous solutions.

Synthesis and Characterization of 7,8,15,16-Tetraazaterrylene

A facile three-step synthesis of 7,8,15,16-tetraazaterrylene (TAT) from phenalene-1,3-dione, with potential application in organic electronics, is reported. Single crystal structure analysis shows one-dimensional columnar stacks with an interplanar distance of 3.352 Å.

Synthesis of Novel Alkylamino Substituted cis and trans Apovincamate Derivatives

Aim To synthesize series of novel alkylamino substituted cis and trans apovincamate derivatives for further structure activity relationship study. Method Starting from cis and trans apovincamate acid, the targeted products were obtained through facile three-step synthesis with moderate yield. Results Twenty four novel alkylamino substituted cis and trans apovincamate derivatives were synthesized for further biological evaluation. Conclusion An efficient method to prepare novel alkylamino substituted cis and trans apovincamate derivatives is developed.

Graphene-wrapped WO3 nanoparticles with improved performances in electrical conductivity and gas sensing properties

WO3/graphene (GN) nanocomposites have been successfully synthesized using a facile three-step synthesis. First, an SrWO4/graphene oxide (GO) precursor was synthesized by homogeneous precipitation; second, the SrWO4/GO precursor was transformed into WO3/GO hybrids by acidification; and third, the WO3/GO hybrids were reduced to WO3/GNvia UV-assisted photoreduction in water instead of general alcoholic solvent at room temperature. The resulting WO3 nanoparticles anchored on graphene sheets as spacers to keep the neighboring sheets separated are approximately quadrangular with a side length of 50–200 nm. Compared with WO3/GO hybrids, WO3/GN nanocomposites show an enhanced electrical conductivity, which results in an improved gas sensing towards alcohol. This work provides a new insight into the fabrication of tungstate–graphene composites and facilitates their application in future.

Me 3SiCl-promoted intramolecular cyclization of aromatic compounds tethered with N, O-acetals leading to the facile preparation of 1,4-benzodiazepine skeletons

The Me 3SiCl-promoted intramolecular aminomethylation of a novel type of N, O-acetals, which were prepared via a facile three-step synthesis from N-alkylaniline derivatives and N-alkyl-2-oxazolidinones that leads to the production of pharmaceutically useful 1,4-benzodiazepine skeletons with a variety of functional groups is described. This method was successfully applied to the facile preparation of both tricyclic benzodiazepine derivatives and a 1,4-benzoxazepine derivative via 7- exo- trig cyclization.

A Versatile Preparation of Geländer-Type p-Terphenyls from a Readily Available Diacetylenic Precursor

A series of doubly bridged p-terphenyls (4) have been synthesized utilizing a facile three-step synthesis starting from the readily available diacetylenic precursor (1) in excellent overall yields, and their structures were confirmed by 1H/13C NMR spectroscopy as well as by X-ray crystallography. The racemization barrier between the meso and chiral atropisomers of one of the derivatives of 4 was found to be approximately 12 kcal/mol by variable-temperature NMR spectroscopy. The versatility of the protocol developed herein was further demonstrated by the preparation of a quadruply bridged penta-p-phenylene derivative.

A facile three-step synthesis of (±)-crispine A via an acyliminium ion cyclisation

A high yielding cyclisation of the readily available N-(4,4-diethoxybutyl)-2-(3,4-dimethoxyphenyl)acetamide to 8,9-bis(methyloxy)-2,3,6,10b-tetrahydropyrrolo[2,1- a]isoquinolin-5(1 H)-one is described. The latter can be reduced with either AlH 3 or BH 3 to (±)-crispine A in an overall yield of 55%.

A novel synthesis of branched high-molecular-weight (C40+) long-chain alkanes.

Many biological and geochemical questions remain concerning the structures, functions, and properties of naturally occurring high-molecular-weight (C40+) alkanes with various mid-chain alkylation patterns. Above C40, these alkanes are exceedingly difficult to separate and purify, and syntheses can be blocked by the low solubility of intermediates. To overcome these problems, a facile three-step synthesis employing the alkylation of 1,3-dithiane with a suitable alpha,omega-dibromoalkane was developed. Bisalkylation of the bis(dithianyl)alkane intermediate with the appropriate 1-bromoalkane and subsequent desulfurization with Raney nickel furnished the desired long-chain alkane. Long-chain alkanes modified at mid-chain and/or symmetrically near the chain termini (or unmodified, i.e., long-chain n-paraffins) are accessible by the selection of appropriate bromoalkanes. Nine mid-chain methylated (C38H78 to C53H108), one symmetrical terminal-chain dimethylated (C40H82), and four linear (C44H90 to C58H118) long-chain alkanes were synthesized by using this approach. High-temperature gas chromatography (HTGC) was found to have important advantages for evaluating the purity of the synthetic high-molecular-weight alkanes.