An analysis of electrophilic aromatic substitution: a “complex approach”

Stamenković, Nikola; Ulrih, Nataša Poklar; Cerkovnik, Janez

doi:10.1039/d0cp05245k

Cited by 27 publications

(21 citation statements)

References 109 publications

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“…Electrophilic aromatic substitution has long been studied and, given the large amount of data reported in the literature, it represents a cornerstone in the field of mechanistic models of organic reactions, which excellent reviews and books have been dedicated to [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Is Aromatic Nitration Spin Density Driven?

2021

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The mechanism of aromatic nitration is critically reviewed with particular emphasis on the paradox of the high positional selectivity of substitution in spite of low substrate selectivity. Early quantum chemical computations in the gas phase have suggested that the retention of positional selectivity at encounter-limited rates could be ascribed to the formation of a radical pair via an electron transfer step occurring before the formation of the Wheland intermediate, but calculations which account for the effects of solvent polarization and the presence of counterion do not support that point of view. Here we report a brief survey of the available experimental and theoretical data, adding a few more computations for better clarifying the role of electron transfer for regioselectivity.

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Section: Introductionmentioning

confidence: 99%

Is Aromatic Nitration Spin Density Driven?

2021

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“…Taking the Friedel–Crafts alkylation reaction as an example, we discussed the EAS reaction and further established comprehensive exercises for juniors to learn about this reaction. For instance, in the intermolecular Friedel–Crafts alkylation reaction, we used DFT calculations to find that the pre-equilibrium does occur in the rearrangement of carbocations. − Juniors could utilize the Curtin–Hammett principle to predict the selectivity of products. They could also analyze the solvent effect as well as the phenomenon that temperature changes influence the energies of transition states in their postlaboratory problems.…”

Section: Assessmentmentioning

confidence: 99%

Using Computational Chemistry to Improve Students’ Multidimensional Understanding of Complex Electrophilic Aromatic Substitution Reactions: Further Analysis of the Solvent Effect, Temperature Influence, and Kinetic Behaviors

Dong

Zhang

2021

J. Chem. Educ.

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Student-centered teaching has become increasingly common in higher education as researchers have demonstrated its efficacy in recent decades. Herein, we hope to establish an efficient problem-based learning (PBL) method, which can help upperdivision students learn organic chemistry content by combining teaching materials, experimental literature, and computational methods in a self-directed way, systematically and deeply. We aim to cultivate the critical-thinking skills of students and to expand modern research methods to analyze, predict, and understand organic chemical processes. On the basis of such goals and ideas, we take the practical Friedel−Crafts alkylation reaction as a model reaction. We focus on two key points, the pre-equilibrium and the rate-determining step (RDS). In combination with the textbook knowledge and DFT calculation method, we attempt to promote the upper-division students to further discuss and understand reaction details, including kinetic-controlled reactions, the Hammond−Leffler postulate, and the Curtin−Hammett principle, etc. Following this approach, we achieve our goals to discuss the Friedel−Crafts alkylation reaction and provide juniors with a deep understanding of the carbon−carbon bond formation reaction. Furthermore, students initially master the DFT calculation method and make a direct connection between experimental observations and computational results. This approach activates students' study interests to further use core ideas of structures and bonding to rationalize complex chemical reaction phenomena for their future learning career.

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“…Reactions of aromatic compounds with electrophiles are among the most common routes for the production of substituted derivatives. [1][2][3] Traditional processes involve use of an acid or other activator, which generates toxic and hazardous materials during work-up. In addition, such reactions often require harsh reaction conditions and lead to low yields because of the production of mixtures of isomers that require separation.…”

Section: Introductionmentioning

confidence: 99%

Polybromination of naphthalene using bromine over a montmorillonite clay and regioselective synthesis of 2,6-dibromonaphthalene

El‐Hiti¹,

Smith²,

Alkhalaf³

et al. 2022

Arkivoc

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Reaction of naphthalene and bromine (three mole equivalents) at room temperature gave 1,4,6tribromonaphthalene (66%) along with 1,4-dibromonaphthalene (8%) and 1,5-dibromonaphthalene (10%). Crystallization of the crude product gave pure 1,4,6-tribromonaphthalene in 50% yield. Bromination of naphthalene using four mole equivalents of bromine over KSF clay gave 1,2,4,6-tetrabromonaphthalene (92%) along with 1,3,5,7-tetrabromonaphthalene (5%). Crystallization of the crude products gave 1,2,4,6tetrabromonaphthalene, a previously unreported compound, and 1,3,5,7-tetrabromonaphthalene in 70% and 4% isolated yields, respectively. Proto-debromination of the crude tetrabromination product, using two mole equivalents of n-butyllithium at a low temperature for a short reaction time, gave 2,6-dibromonaphthalene regioselectively in 82% yield after crystallization.

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An analysis of electrophilic aromatic substitution: a “complex approach”

Abstract: A bigger mechanistic picture of electrophilic aromatic substitution (EAS) is summarized and important “missing” postulates in EAS are unified.

Cited by 27 publications

References 109 publications

Is Aromatic Nitration Spin Density Driven?

Is Aromatic Nitration Spin Density Driven?

Using Computational Chemistry to Improve Students’ Multidimensional Understanding of Complex Electrophilic Aromatic Substitution Reactions: Further Analysis of the Solvent Effect, Temperature Influence, and Kinetic Behaviors

Polybromination of naphthalene using bromine over a montmorillonite clay and regioselective synthesis of 2,6-dibromonaphthalene

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