Using nanosized, homogeneous, and heterogeneous catalytic systems in organic synthesis: changing the structure of active center in chemical reactions in solution

2010 ◽  
Vol 5 (1-2) ◽  
pp. 1-17 ◽  
Author(s):  
V. P. Ananikov ◽  
I. P. Beletskaya
Keyword(s):  
Organic Synthesis ◽  
Active Center ◽  
Chemical Reactions ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic

Design and Preparation of Heterogeneous Catalysts by Controlled Chemical Reactions with Oxygen and Hydrogen

1994 ◽  
Vol 368 ◽  
Author(s):  
David L. Cocke ◽  
Donald G. Naugle ◽  
Thomas R. Hess
Keyword(s):  
Chemical Reactions ◽  
Heterogeneous Catalysts ◽  
Formation Processes ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Reduction Processes ◽  
Alloy Oxidation ◽  
Reaction Models ◽  
Catalyst Systems ◽  
Insight Into

ABSTRACTChemical reactions of metals and strongly interacting alloys such as Cu-Mn, Ni-Ti, Ni-Hf and Ni-Zr with oxygen and hydrogen play important roles in the preparation, activation, and regeneration of many important heterogeneous catalytic systems involving supported and unsupported metals and alloys. Recent advances in the understanding of metal and alloy oxidation is bringing new insight into the reactive design and activation of bi- and multi-metallic catalysts. By surface studies of oxidation, thermal annealing and reduction of selected alloys and their thin films and reaction layers and products we have been able to delineate the factors which are most important to the oxide formation processes and the oxide reduction processes. Reaction models developed from these results are permitting the design of new catalyst systems and providing long sought understanding to explain specific aspects of well established metallic catalysts.

Hydrogen peroxide decomposition on a two-component CuO-Cr2O3 catalyst

1988 ◽  
Vol 53 (8) ◽  
pp. 1636-1646 ◽  
Author(s):  
Viliam Múčka ◽  
Kamil Lang
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Extreme Values ◽  
Catalytic Properties ◽  
Active Components ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Peroxide Decomposition ◽  
Two Component ◽  
Catalytically Active

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.

Chiral imidazolidinones: A class of priviliged organocatalysts in stereoselective organic synthesis

2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Laura Raimondi ◽  
Chiara Faverio ◽  
Monica Fiorenza Boselli
Keyword(s):  
Pharmaceutical Industry ◽  
Green Chemistry ◽  
Organic Synthesis ◽  
Catalytic Synthesis ◽  
Biological Chemistry ◽  
Chiral Molecules ◽  
Catalytic Systems ◽  
Drug Synthesis ◽  
Industry Needs

AbstractChiral molecules hold a mail position in Organic and Biological Chemistry, so pharmaceutical industry needs suitable strategies for drug synthesis. Moreover, Green Chemistry procedures are increasingly required in order to avoid environment deterioration. Catalytic synthesis, in particular organocatalysis, in thus a continuously expanding field. A survey of more recent researches involving chiral imidazolidinones is here presented, with a particular focus on immobilized catalytic systems.

Acceleration of Baylis-Hillman reaction using ionic liquid supported organocatalyst

2021 ◽  
Vol 08 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Catalyst Loading ◽  
Catalyst Recycling ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Highly Active ◽  
Low Catalyst Loading

Background: Baylis-Hillman reaction suffers from the requirement of cheap starting materials, easy reaction protocol, possibility to create the chiral center in the reaction product has increased the synthetic efficacy of this reaction, and high catalyst loading, low reaction rate, and poor yield. Objective: The extensive use of various functional or non-functional ionic liquids (ILs) with organocatalyst increases the reaction rate of various organic transformations as a reaction medium and as a support to anchor the catalysts. Methods: In this manuscript, we have demonstrated the synthesis of quinuclidine-supported trimethylamine-based functionalized ionic liquid as a catalyst for the Baylis-Hillman reaction. Results: We obtained the Baylis-Hillman adducts in good, isolated yield, low catalyst loading, short reaction time, broad substrate scope, accessible product, and catalyst recycling. N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide was also successfully synthesized using CATALYST-3 promoted Baylis-Hillman reaction. Conclusion: We successfully isolated the 25 types of Baylis-Hillman adducts using three different quinuclidine-supported ammonium-based ionic liquids such as Et3AmQ][BF4] (CATALYST-1), [Et3AmQ][PF6] (CATALYST-2), and [TMAAmEQ][NTf2](CATALYST-3) as new and efficient catalysts. Tedious and highly active N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide derivative was also synthesized using CATALYST-3 followed by Baylis-Hillman reaction. Generally, all the responses demonstrated higher activity and yielded high competition with various previously reported homogenous and heterogeneous Catalytic systems. Easy catalyst and product recovery followed by six catalysts recycling were the added advantages of the prosed catalytic system.

scholarly journals Learning from B12 enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

2018 ◽  
Vol 14 ◽  
pp. 2553-2567 ◽  
Author(s):  
Keishiro Tahara ◽  
Ling Pan ◽  
Toshikazu Ono ◽  
Yoshio Hisaeda
Keyword(s):  
Organic Synthesis ◽  
Reaction Mechanisms ◽  
Catalytic Reactions ◽  
Vitamin B ◽  
Catalytic Systems ◽  
New Approach ◽  
Enzyme Functions

Cobalamins (B12) play various important roles in vivo. Most B12-dependent enzymes are divided into three main subfamilies: adenosylcobalamin-dependent isomerases, methylcobalamin-dependent methyltransferases, and dehalogenases. Mimicking these B12 enzyme functions under non-enzymatic conditions offers good understanding of their elaborate reaction mechanisms. Furthermore, bio-inspiration offers a new approach to catalytic design for green and eco-friendly molecular transformations. As part of a study based on vitamin B12 derivatives including heptamethyl cobyrinate perchlorate, we describe biomimetic and bioinspired catalytic reactions with B12 enzyme functions. The reactions are classified according to the corresponding three B12 enzyme subfamilies, with a focus on our recent development on electrochemical and photochemical catalytic systems. Other important reactions are also described, with a focus on radical-involved reactions in terms of organic synthesis.

scholarly journals Pd(0) encapsulated nanocatalysts as superior catalytic systems for Pd-catalyzed organic transformations

RSC Advances ◽  
2016 ◽  
Vol 6 (91) ◽  
pp. 88588-88624 ◽  
Author(s):  
S. Sadjadi ◽  
M. M. Heravi
Keyword(s):  
Chemical Reactions ◽  
Organic Transformations ◽  
Catalytic Systems

In the last decade, Pd(0) nanoparticles have attracted increasing attention due to their outstanding utility as nanocatalysts in a wide variety of key chemical reactions.

scholarly journals Recent Advances in Heterogeneous Catalytic Systems Containing Metal Ions for Phosphate Ester Hydrolysis

2020 ◽  
Author(s):  
Marco Antônio G. B. Gomes ◽  
Christiane Fernandes ◽  
Lawrence R. Gahan ◽  
Gerhard Schenk ◽  
Adolfo Horn
Keyword(s):  
Metal Ions ◽  
Ester Hydrolysis ◽  
Phosphate Ester ◽  
Catalytic Systems ◽  
Phosphate Ester Hydrolysis ◽  
Heterogeneous Catalytic ◽  
Recent Advances

scholarly journals Microwave Assisted Synthesis of Organic Compounds and Nanomaterials

2021 ◽  
Author(s):  
Anjali Jha
Keyword(s):  
Green Chemistry ◽  
Organic Synthesis ◽  
Electric Fields ◽  
Chemical Reactions ◽  
Dipole Moments ◽  
Electric Heating ◽  
Microwave Assisted Synthesis ◽  
Microwave Chemistry ◽  
Microwave Assisted ◽  
Promising Area

In the Conventional laboratory or industry heating technique involve Bunsen burner, heating mental/hot plates and electric heating ovens. To produce a variety of useful compounds for betterment of mankind, the Microwave Chemistry was introduced in year 1955 and finds a place in one of the Green chemistry method. In Microwave chemistry is the science of applying microwave radiation to chemical reactions. Microwaves act as high frequency electric fields and will generally heat any material containing mobile electric charges, such as polar molecules in a solvent or conducting ions in a solid. Polar solvents are heated as their component molecules are forced to rotate with the field and lose energy in collisions i.e. the dipole moments of molecules are important in order to proceed with the chemical reactions in this method. It can be termed as microwave-assisted organic synthesis (MAOS), Microwave-Enhanced Chemistry (MEC) or Microwave-organic Reaction Enhancement synthesis (MORE). Microwave-Assisted Syntheses is a promising area of modern Green Chemistry could be adopted to save the earth.

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