Unveiling the high regioselectivity and stereoselectivity within the synthesis of spirooxindolenitropyrrolidine: A molecular electron density theory perspective

Abstract

A molecular electron density theory (MEDT) study for the [3 + 2] cycloaddition (32CA) reaction of indoledione and N-methyl glycine with (E)-1-bromonitrostyrene leading to the spirooxindole-pyrrolidine adduct is presented. Electron localisation function (ELF) study of the in situ generated azomethine ylide classifies a pseudodiradical electronic structure associated with low activation energies. This 32CA reaction is a polar process with electronic flux from the strongly nucleophilic azomethine ylide to the strongly electrophilic nitrostyrene, confirmed from the global electron density transfer (GEDT) above 0.20 e at the transition states (TSs). Parr function analysis predicts the correct regioselectivity from the two-centre interactions. The reaction is kinetically controlled with negative free energy of reaction which makes it irreversible. The activation enthalpy of the favoured TS is lowered by 3.4, 6.3 and 9.3 kcal mol −1 in methanol relative to the other feasible reaction paths,

Дослідження Фотохімічної Димеризації 3-Гетероарил (Фурил, Тіофіл, Селенофіл І Телурофіл)-Акрилатів Методом DFT

“…The ELF establishes a direct quantitative connection between the electron density distribution and the chemical structure [36][37][38][39][40][41][42][43]. Herein, the reactivity of reactants in dimerization reactions is studied from the ELF topological analysis.…”

Unveiling the synthesis of spirocyclic, tricyclic, and bicyclic triazolooxazines from intramolecular [3 + 2] azide-alkyne cycloadditions with a molecular electron density theory perspective

“…Since the last ve decades, analysis of organic reactions was based on the frontier molecular orbital (FMO) theory until in 2016 Domingo [15] proposed the molecular electron density theory (MEDT) as a promising alternative to study numerous organic reactions by identifying the role of electron density changes in the molecular reactivity. MEDT [15][16][17] has been applied successfully to study varied aspects of cycloaddition reactions since last ve years such as strain promotion [18,19], substituent effects [20,21], chemo- [22,23], stereo-and regioselectivity [24,25], catalysis [26] etc.…”

Unveiling thecb‐typeIntramolecular [3+2] Cycloaddition Reactions of Fluorinated Azomethine Ylides to Ester Carbonyls with a Molecular Electron Density Theory Perspective

“…On the other hand, the cb‐type [6] 32CA reactions involving carbenoid centers characterized by the presence of non‐bonding electron density at a carbon integrating almost 2 e, cannot be related to the electronic structures proposed by Huisgen [7] and Firestone [8] for the TACs. MEDT has been recently applied to study the correlation between changes in electron density and the molecular reactivity to analyze various aspects of 32CA reactions, namely the strain promotion, [14,15] substituent effects, [16,17] chemo‐, [18,19] regio [5] ‐ and stereoselectivity, [5,20] catalysis, [21,22] etc.…”

“…The pdr-type [3] and pmr-type [4] 32CA reactions could be related with the Firestone's mechanism, [8] although the pseudoradical centers of TACs do not correspond to the formation of actual radical centers, but to the presence of non-bonding electron density at one carbon center integrating less than 1 e. [3] On the other hand, the cbtype [6] 32CA reactions involving carbenoid centers characterized by the presence of non-bonding electron density at a carbon integrating almost 2 e, cannot be related to the electronic structures proposed by Huisgen [7] and Firestone [8] for the TACs. MEDT has been recently applied to study the correlation between changes in electron density and the molecular reactivity to analyze various aspects of 32CA reactions, namely the strain promotion, [14,15] substituent effects, [16,17] chemo-, [18,19] regio [5] -and stereoselectivity, [5,20] catalysis, [21,22] etc.…”