Biocatalytic routes toward pharmaceutically important precursors and novel polymeric systems

2005 ◽  
Vol 77 (1) ◽  
pp. 209-226 ◽  
Author(s):  
Sunil K. Sharma ◽  
Mofazzal Husain ◽  
Rajesh Kumar ◽  
Lynne A. Samuelson ◽  
Jayant Kumar ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Organic Synthesis ◽  
Organic Solvents ◽  
Low Cost ◽  
Polymeric Materials ◽  
Environmental Friendliness ◽  
Polymeric Systems ◽  
Wide Range ◽  
Synthetic Sequence

The synthetic potential of enzymes related to organic synthesis has been applied profusely, especially since the introduction of their use in organic solvents. Enzymes offer the opportunity to carry out highly chemo-, regio-, and enantioselective transformations. The use of enzymes in the synthetic sequence provides unique advantages of efficiency and environmental friendliness. Owing to their low cost and applicability to a broad range of substrates, lipases have become the most versatile class of biocatalysts in organic synthesis. We have screened a battery of lipases to carry out highly selective reactions for the synthesis of a wide range of organic compounds and polymeric materials.

scholarly journals Photocatalytic three-component asymmetric sulfonylation via direct C(sp3)-H functionalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shi Cao ◽  
Wei Hong ◽  
Ziqi Ye ◽  
Lei Gong
Keyword(s):  
Asymmetric Catalysis ◽  
Organic Synthesis ◽  
Photochemical Reaction ◽  
Low Cost ◽  
Bioactive Molecules ◽  
Atom Economy ◽  
Mild Conditions ◽  
Wide Range ◽  
Unsaturated Carbonyl Compound ◽  
Direct Functionalization

AbstractThe direct and selective C(sp3)-H functionalization of cycloalkanes and alkanes is a highly useful process in organic synthesis owing to the low-cost starting materials, the high step and atom economy. Its application to asymmetric catalysis, however, has been scarcely explored. Herein, we disclose our effort toward this goal by incorporation of dual asymmetric photocatalysis by a chiral nickel catalyst and a commercially available organophotocatalyst with a radical relay strategy through sulfur dioxide insertion. Such design leads to the development of three-component asymmetric sulfonylation involving direct functionalization of cycloalkanes, alkanes, toluene derivatives or ethers. The photochemical reaction of a C(sp3)-H precursor, a SO2 surrogate and a common α,β-unsaturated carbonyl compound proceeds smoothly under mild conditions, delivering a wide range of biologically interesting α-C chiral sulfones with high regio- and enantioselectivity (>50 examples, up to >50:1 rr and 95% ee). This method is applicable to late-stage functionalization of bioactive molecules, and provides an appealing access to enantioenriched compounds starting from the abundant hydrocarbon compounds.

LED Light Sources in Organic Synthesis: An Entry to A Novel Approach

2021 ◽  
Vol 18 ◽  
Author(s):  
Aparna Das
Keyword(s):  
Organic Compounds ◽  
Organic Synthesis ◽  
Photochemical Reaction ◽  
Low Cost ◽  
Environmentally Friendly ◽  
Photochemical Reactions ◽  
Light Sources ◽  
Blue Led ◽  
Oxidation Reduction ◽  
Novel Approach

: In recent years, photocatalytic technology has shown great potential as a low-cost, environmentally friendly, and sustainable technology. Compared to other light sources in photochemical reaction, LEDs have advantages in terms of efficiency, power, compatibility, and environmentally-friendly nature. This review highlights the most recent advances in LED-induced photochemical reactions. The effect of white and blue LEDs in reactions such as oxidation, reduction, cycloaddition, isomerization, and sensitization is discussed in detail. No other reviews have been published on the importance of white and blue LED sources in the photocatalysis of organic compounds. Considering all the facts, this review is highly significant and timely.

Tin-Mediated Radical Cyclization Reactions

2021 ◽  
Vol 25 ◽  
Author(s):  
Saima malik ◽  
Aditya G. Lavekar ◽  
Bimal Krishna Banik
Keyword(s):  
Organic Compounds ◽  
Organic Synthesis ◽  
Biological Significance ◽  
Radical Cyclization ◽  
Organic Reactions ◽  
Cyclization Reactions ◽  
Complex Molecules ◽  
Radical Chemistry ◽  
Wide Range

: The radical was first come into existence in 1900 by Gomberg, where the triphenylmethane radical was explored. Thus, even to date, two centuries have seen radical chemistry as the methodology of preference in organic synthesis. Due to the fascinating nature of the radical-mediated cyclization reactions, it always caught the eye of organic chemists for the synthesis of novel organic compounds with diverse stereochemistry. Moreover, the development of radical methods further proves beneficial for the synthesis by providing atom- and step-economical methods to complex molecules. Among these, where radical chemistry has been employed, the use of tin-based radical annulation is the most common and widely used field for the synthesis of a wide range of organic reactions with medicinal importance. In this review, we compiled recent tin-mediated radical cyclization reactions toward the synthesis of molecules of biological significance.

scholarly journals Molecular Modeling Investigations of Sorption and Diffusion of Small Molecules in Glassy Polymers

Membranes ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 98 ◽  
Author(s):  
Niki Vergadou ◽  
Doros N. Theodorou
Keyword(s):  
Small Molecules ◽  
Molecular Simulation ◽  
Glassy Polymer ◽  
Polymeric Materials ◽  
Gas Separations ◽  
Polymeric Systems ◽  
Wide Range ◽  
Multiscale Problem ◽  
Polymer Configurations ◽  
And Diffusion

With a wide range of applications, from energy and environmental engineering, such as in gas separations and water purification, to biomedical engineering and packaging, glassy polymeric materials remain in the core of novel membrane and state-of the art barrier technologies. This review focuses on molecular simulation methodologies implemented for the study of sorption and diffusion of small molecules in dense glassy polymeric systems. Basic concepts are introduced and systematic methods for the generation of realistic polymer configurations are briefly presented. Challenges related to the long length and time scale phenomena that govern the permeation process in the glassy polymer matrix are described and molecular simulation approaches developed to address the multiscale problem at hand are discussed.

scholarly journals Development of Technology for Production of Coal-Water Fuel and Determination of the Optimality of Its Combustion

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
N. Aldasheva
Keyword(s):  
Power Plants ◽  
Oil And Gas ◽  
Low Cost ◽  
High Energy ◽  
Fuel Oil ◽  
Energy Potential ◽  
Environmental Friendliness ◽  
Wide Range ◽  
Organic Fuels ◽  
Simple Technology

The article investigates the processes of preparing liquid fuel based on a mixture of coal from the Alai deposit (Kyrgyzstan) and water with the addition of other components, for combustion in various power plants and intended to replace organic fuels (solid fuel, fuel oil and gas). On the basis of the research results, a technological scheme for the preparation of coal-water fuel from the organic matter of the Alai deposit has been developed. Methods and technologies for the preparation of coal-water fuel are described. As a result, an efficient and energy-efficient method for producing coal-water fuel has been developed, which has a high energy potential, environmental friendliness, low cost, a wide range of applications and a fairly simple technology for its implementation.

‘On-water’ organic synthesis: a green, highly efficient, low cost and reusable catalyst system for biaryl synthesis under aerobic conditions at room temperature

RSC Advances ◽  
2015 ◽  
Vol 5 (63) ◽  
pp. 50655-50659 ◽  
Author(s):  
Bishwajit Saikia ◽  
Preeti Rekha Boruah ◽  
Abdul Aziz Ali ◽  
Diganta Sarma
Keyword(s):  
Organic Synthesis ◽  
Room Temperature ◽  
Low Cost ◽  
Suzuki Reaction ◽  
Catalyst System ◽  
Reusable Catalyst ◽  
Wide Range ◽  
Biaryl Synthesis ◽  
Phenylboronic Acids ◽  
Operational Simplicity

The PdCl2/sucrose/K2CO3/H2O system showed the superb catalytic activity towards the Suzuki reaction of a wide range of aryl/heteroaryl halides with diverse phenylboronic acids at room temperature with operational simplicity and shorter reaction time.

Versatile Synthesis of Organic Compounds Derived from Ascorbic Acid.

2021 ◽  
Vol 08 ◽  
Author(s):  
Aparna Das ◽  
Bimal Krishna Banik
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Organic Compounds ◽  
Organic Synthesis ◽  
Biological Activities ◽  
Wide Range ◽  
Derivatives Of

: Ascorbic acid, also known as Vitamin C, is the essential vitamin observed in diverse food. Ascorbic acid has various applications in several fields. Studies have depicted that in organic synthesis, it can be used as a mediator or substrate. The derivatives of ascorbic acid have been found to possess numerous biological activities. In this review, we report the crucial derivatives of ascorbic acid, which have significant biological activities. Various studies are considered in this review to prove its wide range of availability.

Secondary-electron yield measurements of conducting polymers in the Scanning electron microscope

1991 ◽  
Vol 49 ◽  
pp. 1066-1067
Author(s):  
D. M. Susczynsky ◽  
F. I. Klavetter
Keyword(s):  
Conducting Polymers ◽  
Secondary Electron ◽  
Low Cost ◽  
Polymeric Materials ◽  
Rechargeable Batteries ◽  
Photoelectron Emission ◽  
Wide Range ◽  
Charging Current ◽  
Solar Uv ◽  
Typical Satellite

In recent years, research on conducting polymers has been motivated to a large extent by the prospect of developing low-cost, light-weight conducting polymeric materials for commercial use. Conducting polymers have potential uses as electrodes and/or electrolytes for rechargeable batteries, as power conductors andpowercable sheathing and as material for space photovoltaics and spacecraft-charging applications.The utilization of conducting polymers for spacecraft construction and instrumentation requires an understanding of how such materials respond to the spacecraft environment. Of particular importance is how and to what degree such a material will charge when exposed to the wide range of energetic fluxes of electrons and protons that characterize a typical satellite environment. For typical space plasma environments, the total charging current to a satellite is given by the net sum of the electron and proton particle currents from the ambient plasma to the satellite, the secondary-electron and backscatter-electron emission currents arising from ambient-particle impact, and the photoelectron emission current resulting from solar UV.

scholarly journals Reactions of Chlorine Dioxide with Organic Compounds

2016 ◽  
Vol 7 (1) ◽  
pp. 1 ◽  
Author(s):  
I.M. Ganiev ◽  
Q.K. Timergazin ◽  
N.N. Kabalnova ◽  
V.V. Shereshovets ◽  
G.A. Tolstikov
Keyword(s):  
Organic Compounds ◽  
Organic Synthesis ◽  
Chlorine Dioxide ◽  
Rate Constants ◽  
Drinking Water Treatment ◽  
Decay Kinetics ◽  
Reaction Rate Constants ◽  
Wide Range ◽  
Oxidation Of Organic Compounds ◽  
Number Of Publications

<p>Data on the reactivity of chlorine dioxide with organic compounds from various classes are summarized. Early investigations of the reactions of chlorine dioxide were occurred in aqueous or predominantly aqueous solutions in general, because it used in drinking water treatment and in industry as bleaching agent. However, chlorine dioxide was not used widely as reagent in organic synthesis. In last decades the number of publications on the studying interaction of the chlorine dioxide in organic medium increased. In table presented the rate constants reactions of chlorine dioxide with organic compounds published through 2004. Most of the rate constants were determined spectrophotometrically by decay kinetics of chlorine dioxide at 360 nm. Chlorine dioxide may be used for oxidation of organic compounds, because chlorine dioxide is enough reactive and selective as an oxidant with a wide range of organic compounds based on these reaction rate constants. But the application of chlorine dioxide as reagent in organic synthesis is restrained by the lack of data on the kinetics and mechanism of reactions involving chlorine dioxide, as well as data on the product yields and composition, temperature and solvent effects, and catalysts. The pathways of products formation and probable mechanisms of reactions are discussed in the review.</p>

scholarly journals Photocatalytic three-component asymmetric sulfonylation via direct C(sp3)-H functionalization

2021 ◽  
Author(s):  
Shi Cao ◽  
Wei Hong ◽  
Ziqi Ye ◽  
Lei Gong
Keyword(s):  
Asymmetric Catalysis ◽  
Organic Synthesis ◽  
Photochemical Reaction ◽  
Low Cost ◽  
Bioactive Molecules ◽  
Atom Economy ◽  
Mild Conditions ◽  
Wide Range ◽  
Unsaturated Carbonyl Compound ◽  
Direct Functionalization

Abstract The direct and selective C(sp3)-H functionalization of cycloalkanes and alkanes is a highly useful process in organic synthesis owing to the low-cost starting materials, the high step and atom economy. Its application to asymmetric catalysis, however, has been scarcely explored. Herein, we disclose our effort toward this goal by incorporation of dual asymmetric photocatalysis by a chiral nickel catalyst and a commercially available organophotocatalyst with a radical relay strategy through sulfur dioxide insertion. Such design leads to the development of three-component asymmetric sulfonylation involving direct functionalization of cycloalkanes, alkanes, toluene derivatives or ethers. The photochemical reaction of a C(sp3)-H precursor, a SO2 surrogate and a common α,β-unsaturated carbonyl compound proceeds smoothly under mild conditions, delivering a wide range of biologically interesting α-C chiral sulfones with high regio- and enantioselectivity (> 50 examples, up to > 50:1 rr and 95% ee). This method is applicable to late-stage functionalization of bioactive molecules, and provides new access to enantioenriched compounds starting from the abundant hydrocarbon compounds.

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