How effectively bonding evolution theory retrieves and visualizes curly arrows: The cycloaddition reaction of cyclic nitrones

Abstract

In the present work, the electron density flows involved throughout the progress of the four reaction pathways associated with the intramolecular [3 + 2] cycloaddition of cyclic nitrones Z-1 and E-1 are analyzed using the bonding evolution theory. The present study highlights the nonconcerted nature of the processes, which can be described as taking place in several stages. The first stage consists in the depopulation of the initial C N and C C double bonds to render the N lone pair and the corresponding C N and C C single bonds, and these electronic flows initiate the reactions. The C C and C O sigma bond formations take place later on, once the transition states have been overcome. Along the bridged pathways, the C C bond formation process precedes the O C bond formation event, although, along the fused paths, the O C bond formation process occurs first and the formation of the C C bond is the last electronic flow to take place. Finally, curly arrow representations accounting for the timing of the electron flows are obtained from the bonding evolution theory results. K E Y W O R D S bonding evolution theory, curly arrows, cyclic nitrones, intramolecular [3 + 2]cycloaddition

Exploring The Sequence of Electron Density Along The Chemical Reactions Between Carbonyl Oxides And Ammonia/Water Using Bond Evolution Theory

“…An important relationship can exist between these temporal concepts and spatial quantities by analyzing structural stability domain (SSDs). Relative to the position changes of different SSDs found during the BET analysis for a given reaction pathway, we have proposed to evaluate the synchronicity of chemical process by defining the synchronicity indicator [53,54] . Its expression is given by equation . …”

Deciphering the Curly Arrow Representation and Electron Flow for the 1,3-Dipolar Rearrangement between Acetonitrile Oxide and (1S,2R,4S)-2-Cyano-7-oxabicyclo[2.2.1]hept-5-en-2-yl Acetate Derivatives

“…The position of the changes between the different SSDs derived from the BET analysis is employed as an indicator of the synchronicity of a particular process, as was previously defined 69 , 80 …”

“…Very recently, we were able to show how effectively BET retrieves and visualizes curly arrows in the cycloaddition reaction of cyclic nitrones. 69 In the present study, we include a complete BET analysis and recover the curly arrow representation and the corresponding electron flow. Therefore, an added value of the present work with respect to previous articles on the description of reaction mechanisms of similar chemical rearrangements is to disclose how curly arrows meet electron density transfers and electron flow along the rearrangement progress.…”

Topological investigation of the reaction mechanism of glycerol carbonate decomposition by bond evolution theory

“…22,23 For more than twenty years, the topological analysis of the ELFs has been adapted to the study of different types of chemical bonds [24][25][26] and reaction mechanisms. [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] Indeed, such an approach enables to divide the space into different regions corresponding to the chemical objects developed in Lewis valence theory 19 or in the Valence Shell Electron Pair Repulsion (VSEPR) theory, [42][43][44] i.e. the bonds, free pairs, p systems, etc.…”