fine chemistry
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Physchem ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 288-296
Author(s):  
Richail Dubien Moulandou-Koumba ◽  
Frédéric Guégan ◽  
Jean-Maurille Ouamba ◽  
Samuel N’Sikabaka ◽  
Gilles Frapper

Betaine derivatives, especially esters, are compounds of interest for the development of a more sustainable fine chemistry, as they are widely available from biomass and currently produced as side-products from various industries (among which, sugar production). In this publication, we studied the impact of carbon chain length on three considered reaction mechanisms for the esterification of (CH3)3N(CH2)nCO2 betaine (n = 1, 2, 3) with glycerol under acid catalysis. DFT calculations show that the mechanism proposed by Bachmann–Frapper et al. may also be active here, but it can interestingly be seen as an avatar of the former proposition by Watson. Conversely, Ingold’s proposition is in this case too energetically prevented. Overall, lower activation barriers and higher reaction exergonicity are reported, suggesting esterification of longer carbon-chain based betaines is more readily achieved.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shu-Hao Chang

Purpose The application of laser and optical technologies in the industry is wide and extensive; the development and application of laser and optical technologies have become a promising research domain. However, most existing studies have focused on the technical aspects or the application aspects; these studies have not highlighted the technology distribution and application development of laser and optical technologies from the big picture. Additionally, the manner in which the research and development (R&D) results of universities correspond to the needs of enterprises and industry has become a topic of concern for the public. Therefore, this study aims to adopt the academic patents as the basis for analysis and to construct a laser and optical technology network. Design/methodology/approach Therefore, in the current study, the researchers have analyzed relevant academic patent technology networks, using academic patents of laser and optical technologies as a basis of analysis. Findings The study results indicated that the key technologies mainly lie in nanostructures, metal-working, material analysis and semiconductor devices. Additionally, these technologies are mainly applied in industries, such as optics, medical technology, pharmaceuticals, biotechnology and organic fine chemistry; this indicated that a large proportion of academia’s R&D outcomes are applied in these industries. Originality/value In this study, the researchers have constructed a technology network model to explore the technical development direction of laser and optical technologies; the results of the current study could serve as a reference for universities and industry for allocation of R&D resources.


Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1147
Author(s):  
Ferran Sabaté ◽  
María J. Sabater

The present report describes the structural and physical–chemical variations of the potassium manganese oxide mineral, α–MnO2, which is a specific manganese octahedral molecular sieve (OMS) named cryptomelane (K–OMS–2), with different transition metal cations. We will describe some frequently used synthesis methods to obtain isomorphic substituted materials [M]–K–OMS–2 by replacing the original manganese cationic species in a controlled way. It is important to note that one of the main effects of doping is related to electronic environmental changes, as well as to an increase of oxygen species mobility, which is ultimately related to the creation of new vacancies. Given the interest and the importance of these materials, here, we collect the most recent advances in [M]–K–OMS–2 oxides (M = Ag, Ce, Mo, V, Nb, W, In, Zr and Ru) that have appeared in the literature during the last ten years, leaving aside other metal–doped [M]–K–OMS–2 oxides that have already been treated in previous reviews. Besides showing the most important structural and physic-chemical features of these oxides, we will highlight their applications in the field of degradation of pollutants, fine chemistry and electrocatalysis, and will suggest potential alternative applications.


Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 311
Author(s):  
M. Hamami ◽  
M. Bouaziz ◽  
N. Raouafi ◽  
A. Bendounan ◽  
H. Korri-Youssoufi

We report the design of an electrochemical aptasensor for ampicillin detection, which is an antibiotic widely used in agriculture and considered to be a water contaminant. We studied the transducing potential of nanostructure composed of MoS2 nanosheets and conductive polypyrrole nanoparticles (PPyNPs) cast on a screen-printed electrode. Fine chemistry is developed to build the biosensors entirely based on robust covalent immobilizations of naphthoquinone as a redox marker and the aptamer. The structural and morphological properties of the nanocomposite were studied by SEM, AFM, and FT-IR. High-resolution XPS measurements demonstrated the formation of a binding between the two nanomaterials and energy transfer affording the formation of heterostructure. Cyclic voltammetry and electrochemical impedance spectroscopy were used to analyze their electrocatalytic properties. We demonstrated that the nanocomposite formed with PPyNPs and MoS2 nanosheets has electro-catalytic properties and conductivity leading to a synergetic effect on the electrochemical redox process of the redox marker. Thus, a highly sensitive redox process was obtained that could follow the recognition process between the apatamer and the target. An amperometric variation of the naphthoquinone response was obtained regarding the ampicillin concentration with a limit of detection (LOD) of 10 pg/L (0.28 pM). A high selectivity towards other contaminants was demonstrated with this biosensor and the analysis of real river water samples without any treatment showed good recovery results thanks to the antifouling properties. This biosensor can be considered a promising device for the detection of antibiotics in the environment as a point-of-use system.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Miles H. Aukland ◽  
Benjamin List

Abstract During the last 20 years, organocatalysis has significantly advanced as a field. Thanks to contributions from hundreds of groups and companies around the world, the area has risen from a few mechanistically ill-defined niche reactions, to one of the most vibrant and innovative fields in chemistry, providing several well-defined generic activation modes for selective catalysis. Organocatalysis is also on the rise in industrial settings, especially for the production of enantiomers, which are of use in fine chemistry, pharma, crop-protection, and fragrance chemistry. Here we will look at some of the specific elements of organocatalysis that we think are particularly attractive and contribute to this successful development.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 765
Author(s):  
Yudong Meng ◽  
Francesco Taddeo ◽  
Adriana Freites Aguilera ◽  
Xiaoshuang Cai ◽  
Vincenzo Russo ◽  
...  

The epoxidized group, also known as the oxirane group, can be considered as one of the most crucial rings in chemistry. Due to the high ring strain and the polarization of the C–O bond in this three-membered ring, several reactions can be carried out. One can see such a functional group as a crucial intermediate in fuels, polymers, materials, fine chemistry, etc. Literature covering the topic of epoxidation, including the catalytic aspect, is vast. No review articles have been written on the catalytic synthesis of short size, intermediate and macro-molecules to the best of our knowledge. To fill this gap, this manuscript reviews the main catalytic findings for the production of ethylene and propylene oxides, epichlorohydrin and epoxidized vegetable oil. We have selected these three epoxidized molecules because they are the most studied and produced. The following catalytic systems will be considered: homogeneous, heterogeneous and enzymatic catalysis.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2598
Author(s):  
Duo Wei ◽  
Ruqaya Buhaibeh ◽  
Yves Canac ◽  
Jean-Baptiste Sortais

Hydrosilylation is an important process, not only in the silicon industry to produce silicon polymers, but also in fine chemistry. In this review, the development of rhenium-based catalysts for the hydrosilylation of unsaturated bonds in carbonyl-, cyano-, nitro-, carboxylic acid derivatives and alkenes is summarized. Mechanisms of rhenium-catalyzed hydrosilylation are discussed.


2021 ◽  
Vol 99 (8) ◽  
pp. 10-10
Author(s):  
Michael McCoy
Keyword(s):  

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 189
Author(s):  
Jasper Spitters ◽  
Jonathan C. Gonçalves ◽  
Rui P. V. Faria ◽  
Alírio E. Rodrigues

Simulated moving bed technology is applied in the field of pharmaceutical, petrochemical and fine chemistry. It shows capability in separating multicomponent mixtures up to high purities. In this work, an attempt was made to optimize the production of 1,1-diethoxybutane (DEB), using the simulated moving bed technology. A fixed bed model is made with good agreement with experimental results. This fixed bed model was expanded to a simulated moving bed model. This model was used to determine the optimum conditions regarding the switching time and flowrates in each section. From this model, the optimum switching time was found to be 2.4 min, and the ratio of liquid flowrate over the solid flowrate in Section 1Section 2Section 3 and Section 4 of the SMBR was found to be 4.24, 1.77, 3.03 and 1.35, respectively. Under those conditions, the productivity was 19.8 kg DEB per liter of adsorbent per day, and the desorbent consumption was 6.1 L of ethanol per kg of DEB. The results were obtained with a minimum purity of the extract and raffinate of 97%.


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