scholarly journals Self-assembly of TiO2/ZIF-8 nanocomposites for varied photocatalytic CO2 reduction with H2O vapor induced by different synthetic methods

2021 ◽  
Author(s):  
Yan-Hong Zou ◽  
Hai-Ning Wang ◽  
Xing Meng ◽  
Hong-Xu Sun ◽  
Zi-Yan Zhou

Different synthetic approaches give birth to different structures, which result in varied photocatalytic performances.

2019 ◽  
Vol 16 (3) ◽  
pp. 342-368 ◽  
Author(s):  
Ramandeep Kaur ◽  
Yagyesh Kapoor ◽  
Sundeep K. Manjal ◽  
Ravindra K. Rawal ◽  
Kapil Kumar

The furo [2,3-b] indoline ring system is one of the most important structural units in various natural products. It has been known to have inherent biological activities and is utilized as a synthetic target for a number of natural compounds; therefore, this has contributed to a great demand for the growth of synthetic methods for this ring system. Most important compounds with furoindoline ring system are physovenine, madindoline A and B and makomotindoline etc. These compounds are well known to exhibit biological activity against different diseases such as glaucoma, cancer, cachexia, Castleman’s disease, rheumatoid arthritis, etc. The current article focuses on various synthetic approaches for furoindoline containing compounds and essential furoindoline moiety, such as oxindole-5-O-tetrahydropyranyl ether route etc., and various other diastereoand enantio- controlled approach in a very concise way.


Synlett ◽  
2021 ◽  
Author(s):  
Stefan Schulz ◽  
Dennis Poth ◽  
Pardha Saradhi Peram ◽  
Susann Hötling ◽  
Markus Menke ◽  
...  

AbstractFor a long time, frogs were believed to communicate primarily via the acoustic channel, but during the last decades it became obvious that various lineages also use chemical communication. In this Account we present our research on the identification of volatile lactones from Madagascan Mantellidae and African Hyperoliidae frogs. Both possess male specific glands that can disseminate a range of volatile compounds. Key constituents are macrocyclic lactones. They show high variability in structure and occurrence. We focus here on the synthetic approaches we have used to clarify constitution and configuration of the glandular compounds. Key synthetic methods are ring-closing metathesis and nucleophilic epoxide opening. Often, but not always, the natural compounds occurs in amounts that excludes their investigation by NMR spectroscopy. Instead, we use GC/MS analysis, GC/IR, microreactions, and synthesis to identify such components. Several aspects of our work will be described giving some insight in our scientific approach.1 Introduction2 Macrocylic Lactones from the Fatty Acid Biosynthetic Pathway3 Unsaturated Lactones4 Terpenoid Lactones5 Macrolide Occurrence6 Conclusions


Author(s):  
Luana da S. M. Forezi ◽  
Acácio S. de Souza ◽  
Carolina G. S. Lima ◽  
Amanda A. Borges ◽  
Patricia G. Ferreira ◽  
...  

: Naphthoquinones are important molecules belonging to the general class of quinones, and many of these compounds have become drugs that are in the pharmaceutical market for the treatment of several diseases. A special subclass of compounds is that of the bis(naphthoquinones), which have two linked naphthoquinone units. In the last few years, several synthetic approaches toward such valuable compounds have been described, as well as their evaluation against numerous important biological targets. In this review, we provide a thorough discussion on the various synthetic methods reported for the synthesis of bis(naphthoquinone) analogues, also highlighting the biological activities of these substances.


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2417 ◽  
Author(s):  
Jong-Wha Jung ◽  
Nam-Jung Kim ◽  
Hwayoung Yun ◽  
Young Han

4-Arylcoumarins (4-aryl-2H-1-benzopyran-2-one), also known as neoflavones, comprise a minor subclass of naturally occurring flavonoids. Because of their broad-spectrum biological activities, arylcoumarins have been attracting the attention of the organic and medicinal chemistry communities, and are considered as an important privileged scaffold. Since the development of Pechmann condensation, a classical acid-catalyzed condensation between phenol and β-keto-carboxylic acid, several versatile and efficient synthetic approaches for 4-arylcoumarins have been reported. This review summarizes recent advances in the synthesis of the 4-arylcoumarin scaffold by classifying them based on the final bond-formation type. In particular, synthetic methods executed under mild and highly efficient conditions, such as solvent-free reactions and transition metal catalysis, are highlighted.


Author(s):  
Lwazi Ndlwana ◽  
Naledi Raleie ◽  
Mogolodi Dimpe ◽  
Hezron Ogutu ◽  
Mxolisi M Motsa ◽  
...  

There is great importance and need of improving existing carbon materials fabrication methods. As such, this work proposes to discuss, interrogate, and propose viable hydrothermal, solvothermal, and other advanced carbon materials synthetic methods. The advanced carbon materials to be interrogated will include the synthesis of carbon dots, carbon nanotubes, nitrogen/titania-doped carbons, graphene quantum dots, and their nanocomposites with solid/polymeric/metal oxide supports. This will be done with special mind to microwave-assisted solvothermal and hydrothermal synthesis due to their favourable properties such as rapidity, low cost, and green/environmentally-friendliness. Thus, these methods are important during the current and future synthesis and modification of advanced carbon materials for application in energy, gas separation, sensing, and water treatment. Simultaneously, the work will pay special cognizance to methods reducing the fabrication costs and environmental impact while enhancing the properties as a direct result of the synthesis methods. As a direct result, the expectation is to impart a significant contribution to the scientific body of work regarding the improvement of the said fabrication methods.


2021 ◽  
Vol 08 ◽  
Author(s):  
Adarsh Sahu

Background: 1,2,3-triazole is considered widely explored scaffolds by medicinal chemists because of their therapeutic importance. The structural characteristics of 1,2,3-triazoles allow this to mimic certain functional groups demonstrating its utility to prepare new medicinal compounds using the concept of bioisosterism and molecular hybridization. Centered on Huisgens cycloaddition reaction, over the past decade and a half, click chemistry approaches were developed to furnish triazole derivatives with various applications ranging from drugs to bioconjugation linkers. Objective: In the present review, we aim to highlight the different approaches developed for the synthesis of 1,2,3-triazole derivatives and in particular advances in synthetic methods for the last 16 years. This review is also intended to help researchers for finding potential future directions and scope in the development of synthetic strategies. Conclucion: As summarized through the compilation of recent advances for 1,2,3-triazole synthesis, it is clear that these protocols have numerous advantages such as cleaner reaction profile, shorter reaction times, excellent product yields, environmentally benign milder reactions, and safe operations.


RSC Advances ◽  
2019 ◽  
Vol 9 (61) ◽  
pp. 35841-35846
Author(s):  
Jinliang Lin ◽  
Youfeng Li ◽  
Bo Xie

The photochemical reduction of CO2 was studied in a 1-ethyl-3-methylimidazolium tetrafluoroborate, triethanolamine and water ([Emim]BF4 + TEOA + H2O) system under visible light irradiation.


Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1116
Author(s):  
Young In Choi ◽  
Ju Hyun Yang ◽  
So Jeong Park ◽  
Youngku Sohn

Co/Co2C/C hybrids were prepared employing a new synthetic route and demonstrated as materials for energy storage and CO2 recycling application. Herein, an anaerobic ethanol oxidation reaction over Co3O4 nanoparticles (NPs) was first employed to fabricate Co/Co2C/C hybrids using sacrificial SnO2. In the absence of SnO2, Co3O4 NPs were converted to alpha and beta metallic Co. On the other hand, using sacrificial SnO2 resulted in the formation of Co2C and Co embedded in the carbon matrix at approximately 450 °C, as determined by temperature-programmed mass spectrometry analysis. The newly developed materials were fully examined by X-ray diffraction crystallography, scanning electron microscopy, energy-dispersive X-ray analysis, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The Co/Co2C/C hybrids showed a specific capacitance of 153 F/g at a current density of 0.5 A/g. Photocatalytic CO2 reduction experiments were performed and generated CO, CH4, and CH3OH as reduction products with yields of 47.7, 11.0, and 23.4 μmol/g, respectively. The anaerobic ethanol oxidation reaction could be a very useful method for the development of carbon-supported metal carbides, which have not been achieved by other synthetic methods. Furthermore, the demonstration tests unveiled new application areas of Co carbide materials.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Joseph C. Sloop

Heterocyclic molecules incorporating fluorinated isoquinoline components are found in many medicinally and agriculturally important bioactive products as well as industrially impactful materials. Within the past decade, a variety of isoquinolinic ring assembly techniques has enabled the introduction of diverse fluorine-containing functionalities which can enhance potential bioactivity and industrial utility. This review examines recent noncatalyzed and transition metal catalyzed synthetic approaches to the assembly of isoquinoline derivatives that are ring-fluorinated and/or result in the incorporation of fluorine-containing functional groups. Specifically, efficient synthetic methods and regioselectivity in the incorporation of functional groups into isoquinoline ring systems are examined.


Author(s):  
Gokhan Barin ◽  
Ross S. Forgan ◽  
J. Fraser Stoddart

The chemistry of mechanically interlocked molecules (MIMs), in which two or more covalently linked components are held together by mechanical bonds , has led to the coining of the term mechanostereochemistry to describe a new field of chemistry that embraces many aspects of MIMs, including their syntheses, properties, topologies where relevant and functions where operative. During the rapid development and emergence of the field, the synthesis of MIMs has witnessed the forsaking of the early and grossly inefficient statistical approaches for template-directed protocols, aided and abetted by molecular recognition processes and the tenets of self-assembly. The resounding success of these synthetic protocols, based on templation, has facilitated the design and construction of artificial molecular switches and machines, resulting more and more in the creation of integrated functional systems. This review highlights (i) the range of template-directed synthetic methods being used currently in the preparation of MIMs; (ii) the syntheses of topologically complex knots and links in the form of stable molecular compounds; and (iii) the incorporation of bistable MIMs into many different device settings associated with surfaces, nanoparticles and solid-state materials in response to the needs of particular applications that are perceived to be fair game for mechanostereochemistry.


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