Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

E1 Reaction: Stereochemistry and Regiochemistry

E1 Reaction: Stereochemistry and Regiochemistry

One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...

E2 Reaction: Stereochemistry and Regiochemistry

E2 Reaction: Stereochemistry and Regiochemistry

Elimination reactions of alkyl halides can yield one or more alkenes depending on the specific regiochemical and stereochemical considerations. While the regiochemistry of the reaction governs the location of the double bond in the product, the stereochemical requirements often influence the geometry.
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major...

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.

E2 Reaction: Kinetics and Mechanism

E2 Reaction: Kinetics and Mechanism

SN2 substitutions and E2 eliminations of alkyl halides proceed via a concerted pathway. While the nucleophile attacks the alpha carbon in SN2 reactions, it functions as a strong base and abstracts a beta hydrogen in the E2 mechanism. The rate-limiting transition state in E2 elimination reactions is characterized by partially broken carbon–hydrogen and carbon–halogen bonds and a partially formed pi bond between the alpha and beta carbons. The beta hydrogen and halide are eliminated...

Regioselectivity of Electrophilic Additions-Peroxide Effect

Regioselectivity of Electrophilic Additions-Peroxide Effect

In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Effect of the [Fe(salen)]<sub>2</sub>-μ-oxo Catalyst Electronic Structure on Reductive Hydroamination.

Inorganic chemistry·2025

Same author

Structural and Gas Uptake Studies on Iron(II) β‑Diketiminate Metallomacrocycles.

Organometallics·2025

Same author

Intercepting Methanimine for the Synthesis of Piperidine-Based <i>N</i>-Heterocycles in an Aqueous Medium.

The Journal of organic chemistry·2025

Same author

Synthetic and Mechanistic Studies into the Reductive Functionalization of Nitro Compounds Catalyzed by an Iron(salen) Complex.

Journal of the American Chemical Society·2024

Same author

Bromide-Mediated Silane Oxidation: A Practical Counter-Electrode Process for Nonaqueous Deep Reductive Electrosynthesis.

JACS Au·2024

Same author

Synthesis and Characterization of a Terminal Iron(II)-PH<sub>2</sub> Complex and a Series of Iron(II)-PH<sub>3</sub> Complexes.

Inorganic chemistry·2024

Search research articles

Related Experiment Video

Updated: Jan 10, 2026

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Published on: June 21, 2017

Highly E-Selective Alkene Isomerization Using Me₄NF at Room Temperature.

Leah Webster¹, Rofiat Ayoola Shoetan², Catherine M Alder³

¹Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.

The Journal of Organic Chemistry

|November 24, 2025

Summary

Tetramethylammonium fluoride (Me4NF) efficiently catalyzes allylbenzene isomerization to trans-β-methylstyrene with high selectivity. This catalytic method works for various substituents but is sensitive to polar, protic functional groups.

More Related Videos

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Published on: December 16, 2022

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

Published on: August 16, 2018

Related Experiment Videos

Last Updated: Jan 10, 2026

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Published on: June 21, 2017

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Published on: December 16, 2022

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

Published on: August 16, 2018

Area of Science:

Organic Chemistry
Catalysis
Isomerization Reactions

Background:

Allylbenzene isomerization is a key transformation in organic synthesis.
Developing selective and efficient catalysts for isomerization is crucial.

Purpose of the Study:

To investigate the catalytic activity of tetramethylammonium fluoride (Me4NF) for allylbenzene isomerization.
To achieve high E-selectivity in the isomerization to trans-β-methylstyrene.
To explore the scope and limitations of the developed catalytic system.

Main Methods:

Allylbenzene isomerization reaction.
Catalysis using tetramethylammonium fluoride (40 mol %).
Reaction conducted in dry acetonitrile (CD3CN) under an inert atmosphere at room temperature.

Main Results:

High yield and excellent E-selectivity (E:Z = 100:0) for trans-β-methylstyrene.
The catalytic system tolerates a variety of substituents on the allylbenzene substrate.
The method's limitations include sensitivity to polar and protic functional groups.

Conclusions:

Tetramethylammonium fluoride is an effective catalyst for the selective isomerization of allylbenzene.
The developed method offers a practical route to trans-β-methylstyrene.
Preliminary mechanistic insights into the catalytic process were obtained.