Cobalt catalyzed isomerization of alkenes

Synthesis ◽  
2021 ◽  
Author(s):  
Sheng Zhang ◽  
Michael Findlater
Keyword(s):  
Reaction Mechanism ◽  
Short Review ◽  
Positional Isomerization ◽  
Geometric Isomerization ◽  
Alkene Isomerization ◽  
Meaningful Comparison ◽  
Catalytic Isomerization

Catalytic isomerization of alkenes is a highly atom-economical approach to upgrade from lower- to higher-value alkenes. Consequently, tremendous attention has been devoted to the development of this transformation, approaches which exploit cobalt-catalysis are particularly attractive. This short review focuses on the cobalt-catalyzed alkene isomerization, including positional isomerization, geometric isomerization and cycloisomerization. Three main types of reaction mechanism have been discussed to help the reader to better understand and make meaningful comparison between the different transformations. 1 Introduction 2 Positional isomerization 3 Geometric isomerization 4 Cycloisomerization 5 Conclusion and Outlook

scholarly journals A Short Perspective on Electrochemical CO2 Reduction to CO

2020 ◽  
Vol 74 (6) ◽  
pp. 478-482
Author(s):  
Maxime Tarrago ◽  
Shengfa Ye
Keyword(s):  
Electronic Structure ◽  
Reaction Mechanism ◽  
Catalytic System ◽  
Co2 Reduction ◽  
Short Review ◽  
Product Selectivity ◽  
Electrochemical Co2 Reduction ◽  
Co Reduction

This short review summarizes examples of many homogeneous non-noble catalysts for CO2-to-CO reduction and compares their feasible mechanisms. The focus is to show that elucidating the electronic structure of the catalytic system likely provides better understanding of the reaction mechanism and product selectivity.

scholarly journals Catalytic, contra-Thermodynamic Alkene Isomerization

2021 ◽  
Author(s):  
Gino Occhialini ◽  
Vignesh Palani ◽  
Alison Wendlandt
Keyword(s):  
Natural Product ◽  
Catalyst System ◽  
Natural Product Synthesis ◽  
Mechanistic Studies ◽  
Double Bonds ◽  
Positional Isomerization ◽  
Alkene Isomerization ◽  
Terminal Alkene ◽  
Homolytic Substitution ◽  
Powerful Strategy

The positional isomerization of C–C double bonds is a powerful strategy for the interconversion of alkene regioisomers. However, existing methods provide access to thermodynamically more stable isomers from less stable starting materials. Here we report the discovery of a dual catalyst system that promotes contra-thermodynamic positional alkene isomerization under photochemical irradiation, providing access to terminal alkene isomers directly from conjugated, internal alkene starting materials. The utility of the method is demonstrated in the deconjugation of diverse electron rich/poor alkenes and through strategic application to natural product synthesis. Mechanistic studies are consistent with a regiospecific bimolecular homolytic substitution (SH2') mechanism proceeding through an allyl-cobaloxime intermediate.

scholarly journals Ag2O versus Cu2O in the Catalytic Isomerization of Coordinated Diaminocarbenes to Formamidines: A Theoretical Study

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 491
Author(s):  
Juan F. Van der Maelen ◽  
Javier Ruiz
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Carbon Atom ◽  
Transition State ◽  
Theoretical Study ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Similar Reaction ◽  
Isomerization Process ◽  
Catalytic Isomerization

DFT theoretical calculations for the Ag2O-induced isomerization process of diaminocarbenes to formamidines, coordinated to Mn(I), have been carried out. The reaction mechanism found involves metalation of an N-H residue of the carbene ligand by the catalyst Ag2O and the formation of a key transition state showing a μ-η2:η2 coordination of the formamidinyl ligand between manganese and silver, which allows a translocation process of Mn(I) and silver(I) ions between the carbene carbon atom and the nitrogen atom, before the formation of the formamidine ligand is completed. Calculations carried out using Cu2O as a catalyst instead of Ag2O show a similar reaction mechanism that is thermodynamically possible, but highly unfavorable kinetically and very unlikely to be observed, which fully agrees with experimental results.

scholarly journals Transition metal-catalyzed alkene isomerization as an enabling technology in tandem, sequential and domino processes

2021 ◽  
Author(s):  
Daniele Fiorito ◽  
Simone Scaringi ◽  
Clément Mazet
Keyword(s):  
Transition Metal ◽  
Value Added ◽  
Enabling Technology ◽  
One Pot ◽  
Alkene Isomerization ◽  
Catalytic Isomerization ◽  
Conventional Methods ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Value Added Products

One-pot reactions based on catalytic isomerization of alkenes not only offer the inherent advantages of atom-, step- and redox-economy but also enable the preparation of value-added products that would be difficult to access by conventional methods.

scholarly journals Oxidation of Ammonia Nitrogen with Ozone in Water: A Mini Review

2020 ◽  
Vol 3 (1) ◽  
pp. 17
Author(s):  
Philip Anggo Krisbiantoro ◽  
Koki Kato ◽  
Lina Mahardiani ◽  
Yuichi Kamiya
Keyword(s):  
Reaction Mechanism ◽  
Low Temperature ◽  
Atmospheric Pressure ◽  
Oxidation Reaction ◽  
Review Paper ◽  
Short Review ◽  
Ammonia Nitrogen ◽  
Catalytic Reactions ◽  
Sustainable Environment ◽  
Oxidation Of Ammonia

Since ammonia nitrogen is a pollutant causing eutrophication, it must be removed from wastewater to develop sustainable environment and society. Ozonation, which is an oxidation reaction with ozone, is an effective and efficient method for the removal of ammonia nitrogen in wastewater because the reaction can proceed at low temperature and atmospheric pressure. Although the researches in ozonation of ammonia nitrogen have been going on for the last five decades, the reaction mechanism has not yet been well understood and the papers focusing on the reaction mechanism are very few. In this short review paper, the progress in oxidation of ammonia nitrogen with ozone both in non-catalytic and catalytic reactions is summarized to provide a better understanding on the reaction mechanism for ozonation of ammonia nitrogen in water.

scholarly journals A primer on electrocatalysis

2005 ◽  
Vol 70 (3) ◽  
pp. 475-487 ◽  
Author(s):  
M.J. O`Bockris
Keyword(s):  
Reaction Mechanism ◽  
Rational Choice ◽  
Oxygen Reduction ◽  
Electrochemical Oxidation ◽  
Hydrogen Evolution ◽  
Short Review ◽  
Rate Determining Step ◽  
Organic Fuels

A short review of the development and achievement of electrocatalysis in the last 50 years is given. The need for the knowledge of the reaction mechanism and position of the rate determining step for rational choice of catalyst is particularly stressed. Fundamental aspects of electrocatalysis are elaborated in more detail on the examples of electrochemically important reactions of hydrogen evolution and oxygen reduction, as well on the reaction of electrochemical oxidation of organic fuels (e.g., methanol).

Pollutant Identification by Selected Area Electron Diffraction

1974 ◽  
Vol 32 ◽  
pp. 532-533
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson ◽  
C. W. Walker
Keyword(s):  
Thermal Treatment ◽  
Electron Diffraction ◽  
Sample Preparation ◽  
Crystal Structures ◽  
Water Samples ◽  
Environmental Samples ◽  
Short Review ◽  
Selected Area Electron Diffraction ◽  
Multiple Component

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.

Sign in / Sign up

Export Citation Format

Share Document