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

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.

Study of stiff differential equations of mathematical description of izomerization of pentane-hexane cut process

This paper provides a brief overview of the existing definitions of a stiff system of differential equations. Further, on the example of the accepted scheme of chemical transformations of the catalytic isomerization process of the pentane-hexane fraction, the stiffness of the system of differential equations was studied. In the course of the work, a method for studying the direct kinetic problem for stiffness is presented. In the Matlab software, the results of solving a system of differential equations by five methods (solvers) were compared. The given method can be tried for solving other problems of chemical kinetics.

Catalytic Isomerization of Olefins and Theirs Derivatives: A Brief Overview

Carbon–carbon double bond (CCDB) isomerization is a method for synthesizing new organic compounds from olefins and their derivatives, which was based on C=C migration along carbon chain and cis/trans transform, and it plays a vital role in the fields of organic synthesis, synthesis of daily chemicals, raw oil’s development and synthesis of natural products and so on. In this paper, advances of five types of catalytic methods for CCDB of olefins and their derivatives since the 1960s were discussed in detail; Based on his recent work, the author mainly introduces the application and development of photocatalysis in CCDB of olefins and their derivatives.

Cobalt catalyzed isomerization of alkenes

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