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

Cycloaddition Reactions: Overview

Cycloaddition Reactions: Overview

Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.

Cycloaddition Reactions: MO Requirements for Thermal Activation

Cycloaddition Reactions: MO Requirements for Thermal Activation

Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.

Nucleophilic Aromatic Substitution: Elimination–Addition

Nucleophilic Aromatic Substitution: Elimination–Addition

Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is...

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.

Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene

Electrophilic 1,2- and 1,4-Addition of X₂ to 1,3-Butadiene

Electrophilic addition of halogens to alkenes proceeds via a cyclic halonium ion to form a 1,2-dihalide or a vicinal dihalide.

You might also read

Related Articles

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

Sort by

Same author

Simultaneous Oblique Lumbar Interbody Fusion and Percutaneous Pedicle Screw Fixation Combined With Endoscopic-Assisted Decompression in the Lateral Position for Two-Level Lumbar Pathology.

Cureus·2026

Same author

Copper-mediated stepwise polymerization of benzynes: construction of amphiphilic block copolymers and their self-assembly in water.

RSC advances·2026

Same author

Comparison of Surgical Outcomes Between Vertebral Body Stenting (VBS) and Balloon Kyphoplasty (BKP)-Multicenter Cohort Study.

Journal of clinical medicine·2026

Same author

Radiographic subsidence after single-level anterior cervical discectomy and fusion; a comparison between blade-anchored zero-profile cages and stand-alone cages.

Journal of orthopaedic surgery and research·2026

Same author

Cerium isotopes unveil hydrogenetic Fe-Mn encrustation occurring throughout from the oxygen minimum zone to the deep pacific.

Science advances·2026

Same author

Geometric feature analysis for identifying and characterizing normal variations on chest radiographs.

BMC medical imaging·2026

Same journal

A Domino-Synthesized Dicoordinate Copper(I) Bis-imidazopyridine Complex Triggering Cuproptosis/Ferroptosis for Enhanced Cancer Immunotherapy.

Angewandte Chemie (International ed. in English)·2026

Same journal

Mirror-Symmetric Organic Two-Dimensional Crystals for Alternative Photon Transport Pathways.

Angewandte Chemie (International ed. in English)·2026

Same journal

Cobalt-Catalyzed Migratory E-Selective Asymmetric Aza-Nozaki-Hiyama-Kishi Coupling.

Angewandte Chemie (International ed. in English)·2026

Same journal

Facile Synthesis of α,ω-Dihydroxy Telechelic Macromonomers From Ethylene and α-Olefins for Recyclable Alternating Block Copolymers.

Angewandte Chemie (International ed. in English)·2026

Same journal

Multi-Atom Sub-Nanometer Assemblies on Interpenetrating Multi-Chambered N/C Nanospheres.

Angewandte Chemie (International ed. in English)·2026

Same journal

A Synergistic C<sub>2+</sub> Alcohols/Olefins-Intermediated Pathway Boosts CO<sub>2</sub> Hydrogenation to Aromatics.

Angewandte Chemie (International ed. in English)·2026

See all related articles

Search research articles

Related Experiment Video

Updated: Dec 24, 2025

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

Intramolecular Benzyne-Phenolate [4+2] Cycloadditions.

Hiroshi Takikawa^1,2, Arata Nishii¹, Hiromu Takiguchi¹

¹Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.

Angewandte Chemie (International Ed. in English)

|April 10, 2020

Summary

This summary is machine-generated.

This study details an intramolecular benzyne-phenolate [4+2] cycloaddition. Novel precursors efficiently form benzobarrelenes via halogen-metal exchange and cycloaddition reactions.

Keywords:

benzyne cycloaddition polycycles silicon synthetic methods

More Related Videos

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes

Published on: December 16, 2019

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Related Experiment Videos

Last Updated: Dec 24, 2025

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes

Published on: December 16, 2019

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Area of Science:

Organic Chemistry
Synthetic Chemistry

Background:

Intramolecular cycloaddition reactions are crucial for constructing complex molecular architectures.
Benzyne chemistry offers a versatile platform for carbon-carbon bond formation.

Purpose of the Study:

To report a novel intramolecular benzyne-phenolate [4+2] cycloaddition reaction.
To synthesize benzobarrelene derivatives using readily accessible precursors.

Main Methods:

Synthesis of benzyne precursors bearing vicinal halogen-sulfonate functionalities.
Treatment of precursors with organometallic reagents (Ph3MgLi or nBuLi) to induce halogen-metal exchange.
Facilitation of intramolecular [4+2] cycloaddition between the generated benzyne and the tethered phenolate.

Main Results:

Efficient formation of benzobarrelenes through the intramolecular cycloaddition.
Demonstration of the reaction's utility with various tether groups.
Successful generation of reactive benzyne intermediates under mild conditions.

Conclusions:

The reported method provides a facile route to benzobarrelenes.
This intramolecular cycloaddition expands the synthetic utility of benzyne chemistry.
The strategy is amenable to the synthesis of diverse polycyclic compounds.