Does a fluorinated Lewis acid catalyst change the molecular mechanism of the decomposition process of nitroethyl carboxylates?

Abstract

The molecular mechanism of the decomposition reaction of nitroethyl benzoates catalyzed by Lewis acids based on boron element-BH 3 and BF 3 -was studied using density functional theory methods. These reactions take place much faster than the uncatalyzed process. However, the presence of fluorinated Lewis acids has a unique influence on the molecular mechanism. In the case of BF 3 , a change from a one-step mechanism to a two-step one involving a zwitterionic intermediate is observed.

Understanding the Molecular Mechanism of Thermal and LA-Catalysed Diels–Alder Reactions between Cyclopentadiene and Isopropyl 3-Nitroprop-2-Enate

“…Within this complex, the boron atom was located near the oxygen atom of the nitroalkene molecular segment. Similar complexes between the nitro group and Lewis Acids were detected recently [ 36 , 37 , 38 ]. This intermediate was stabilised via coulombic interactions between the boron shell, characterised by a positive partial charge, and the nitro group’s oxygen atom, characterised by a negative partial charge.…”

Understanding the Molecular Mechanism of the Rearrangement of Internal Nitronic Ester into Nitronorbornene in Light of the MEDT Study

“…This paper is a continuation of a comprehensive mechanistic study of the reaction mechanism using the Molecular Electron Density Theory (MEDT) [22,23]. This theory, proposed by Domingo in 2016 [24], in which it is established that changes in electron-density, and not molecular orbital interactions, are responsible for reactivity in organic chemistry, uses quantum chemical tools such as the conceptual Density Functional Theory (DFT) [25,26] reactivity indicator and the topological Electron Localization Function (ELF) [27] analysis of the changes in the molecular electron-density along the reaction path, in order to study organic reactions.…”

“…In order to understand the rearrangement, an MEDT study [22,23] of the transformation of 1 as a model nitronic ester into nitronorbornene 2 (Scheme 1) was carried out at the B3LYP/6-31G(d) computational level, in which a combination of: (i) ELF topological analysis and a Natural Population Analysis (NPA) of the HDA cycloadduct 1 was performed in order to characterize its electronic structure, (ii) Bonding Evolution Theory (BET) [38] and Noncovalent Interactions (NCIs) study of the transformation of HDA cycloadduct 1 to DA cycloadduct 2 , and (iii) MEDT study of the rearrangement.…”