C—C bond formation in the intramolecular Diels-Alder reaction of triene amides

Abstract

The mechanism nature of the intramolecular Diels–Alder reaction has been performed; and thus, the changes of C—C bond forming/breaking along IRC are characterized in this study. Conceptual DFT analyses of the most favorable adduct fused/exo shows that the flux electronic will take place from diene to dienophile moiety. Moreover, ELF topological analysis based on the electron density predicts that C—C bond is formed by the coupling of two pseudoradical centers generated at the most significant atoms of the molecules. However, C2 vs C3, also C1 and C4 interaction comes mainly from the global electron density transfer which takes place along the reaction. Two- stage one-step is the proposed mechanism of this reaction, the first stage aims for the formation of C2—C3 σ bond while the second stage aims for C1—C4 σ bond formation. Interestingly, the observed asynchronicity of this IMDA reaction due principally to the asymmetric reorganization of electron density at the most attractive centers.

Fragmentation of 1,4,2-Oxathiazole Derivative to Provide Anticancer Isothiocyanates Product: Is the C-5 and C-3 Substituent Responsible?

“…Herein, to provide an overall explanation, our study will be widened to the substituent at the position 3, both attractors and donor's substituents have to be experienced. For that purpose, the electron localization function (ELF) method [13], quantum theory of atoms-in molecules (QTAIM) [14,15], bonding evolution theory (BET) [16], and the conceptual density functional theory (CDFT) [17][18][19], have emerged to analyze the chemistry proprieties of an element and the reaction mechanism [20][21][22][23][24][25], within a new reactivity model namely Molecular Electron Density Theory (MEDT) [26]. Considering this fact, a complete investigation will be achieved.…”

Unraveling the Polarization Effect of Sulfur Atom on the Mechanism and Selectivity in the 32CA Involving C–S and C–O Interactions: A Rationalization Study Using Bonding Evolution Theory

“…Generally, nitrile oxides prefer to react with a double or three multiple bonds to generate five-and six-heterocycles with a rapid fashion. Several studies have been devoted to characterize and explore the 32CA reactions [9,10] and the remaining cycloaddition organic reactions [11][12][13][14][15], a very little paper that implicate the utilization of electron density function (ELF) within the molecular electron density theory (MEDT), together with the density functional theory (DFT) were performed, Domingo and co-workers have shown the utility and flexibility associated to these manners for exploring the molecular mechanism, providing a very suggestive graphical presentation of the molecular mechanism, it should be noted that ELF is a tool that could establishing the change of electron density for a quantum mechanical observable a long of a reaction pathway have led to the understanding of the bond forming/breaking processes with a more accurate conviction [16][17].…”

An electron localization function analysis of the molecular mechanism and the C–O bond formation in the [3+2] cycloaddition reaction involving zwitterionic type between a nitrone and an electron deficient ethyne

“…4–9 In the present decade, calculations of the quantum mechanical observables along the reaction pathway have led to an understanding of the bond-forming and bond-breaking processes. 6,10 For this purpose, the electron localization function (ELF) 11,12 method and bonding evolution theory (BET) 13 have emerged to analyze reaction mechanisms. 14–19 The ELF is considered as a new tool for analyzing electronic changes in chemical processes and is considered as an appealing procedure that provides a more straightforward relationship between the electron population reorganization and the chemical structure.…”

“…In this sense, density functional theory (DFT) has proven to be very useful for studying structure and reactivity. [4][5][6][7][8][9] In the present decade, calculations of the quantum mechanical observables along the reaction pathway have led to an understanding of the bond-forming and bond-breaking processes. 6,10 For this purpose, the electron localization function (ELF) 11,12 method and bonding evolution theory (BET) 13 have emerged to analyze reaction mechanisms.…”