Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Intramolecular Claisen Condensation of Dicarboxylic Esters: Dieckmann Cyclization01:13

Intramolecular Claisen Condensation of Dicarboxylic Esters: Dieckmann Cyclization

3.2K
Dieckmann cyclization is an intramolecular Claisen condensation of diesters. The reaction occurs in the presence of a base and generates a cyclic β-ketoester as the final product. Commonly, 1, 6 and 1, 7-diesters are preferred substrates for the reaction since the generated five, and six-membered cyclic β-keto esters are particularly more stable.
3.2K
Acid-Catalyzed Ring-Opening of Epoxides02:24

Acid-Catalyzed Ring-Opening of Epoxides

8.8K
Epoxides that are three-membered ring systems are more reactive than other cyclic and acyclic ethers. The high reactivity of epoxides originates from the strain present in the ring. This ring strain acts as a driving force for epoxides to undergo ring-opening reactions either with halogen acids or weak nucleophiles in the presence of mild acid. The acid catalyst converts the epoxide oxygen, a poor leaving group, into an oxonium ion, a better leaving group, making the reaction feasible. The...
8.8K
Base-Catalyzed Ring-Opening of Epoxides02:26

Base-Catalyzed Ring-Opening of Epoxides

10.1K
Due to their highly strained structures, epoxides can readily undergo ring-opening reactions through nucleophilic substitution, either in the presence of an acid or a base. The nucleophilic substitution reactions in the presence of acid are called acid-catalyzed ring-opening reactions, and nucleophilic substitution reactions in the presence of a base are called base-catalyzed ring-opening reactions. Epoxides undergo base-catalyzed ring-opening reactions in the presence of a strong nucleophile...
10.1K
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene01:13

Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene

7.4K
Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
7.4K
Acid-Catalyzed Hydration of Alkenes02:45

Acid-Catalyzed Hydration of Alkenes

17.1K
Alkenes react with water in the presence of an acid to form an alcohol. In the absence of acid, hydration of alkenes does not occur at a significant rate, and the acid is not consumed in the reaction. Therefore, alkene hydration is an acid-catalyzed reaction.
17.1K
Base-Catalyzed Aldol Addition Reaction01:08

Base-Catalyzed Aldol Addition Reaction

4.5K
As depicted in Figure 1, base-catalyzed aldol addition involves adding two carbonyl compounds in aqueous sodium hydroxide to form a β-hydroxy carbonyl compound.
4.5K

You might also read

Related Articles

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

Sort by
Same author

N-N-N-N-O Benzotriazole Carbamates by Hypervalent Iodane Mediated Cross-Dehydrogenative N-N Coupling.

The Journal of organic chemistry·2026
Same author

Aza[7]helicene Diimide: Backbone-Controlled Excited-State Charge Transfer and Electronic Coupling.

Organic letters·2026
Same author

Investigating Halogen Bonds as Pairing Force in an Artificial DNA Base Pair.

Journal of the American Chemical Society·2026
Same author

A computational analysis of substituent effects in pnictogen-, chalcogen-, and halogen-bond donors.

Organic & biomolecular chemistry·2025
Same author

Titanium cis-DACH Salan Catalyst for the Efficient Epoxidation of Nonactivated Olefins with Hydrogen Peroxide-Terminal-Selective Epoxidation of Multiply Unsaturated Terpenes.

Chemistry (Weinheim an der Bergstrasse, Germany)·2025
Same author

Asymmetric synthesis of C-N axially chiral carbazoles <i>via</i> axial-to-axial chirality transfer.

Organic & biomolecular chemistry·2025

Related Experiment Video

Updated: Jan 23, 2026

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers
10:19

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers

Published on: September 27, 2018

10.2K

Iodine-Catalyzed Nazarov Cyclizations.

Jonas J Koenig1, Thiemo Arndt1, Nora Gildemeister1

  • 1Department of Chemistry , University of Cologne , Greinstraße 4 , 50939 Köln , Germany.

The Journal of Organic Chemistry
|June 13, 2019
PubMed
Summary

This study introduces a mild, metal-free Nazarov cyclization using molecular iodine as a catalyst. This method efficiently synthesizes substituted cyclopentenones from various divinyl ketones under diverse solvent conditions.

More Related Videos

An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter
07:28

An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter

Published on: July 13, 2018

7.8K
Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS
06:34

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS

Published on: June 20, 2014

14.3K

Related Experiment Videos

Last Updated: Jan 23, 2026

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers
10:19

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers

Published on: September 27, 2018

10.2K
An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter
07:28

An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter

Published on: July 13, 2018

7.8K
Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS
06:34

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS

Published on: June 20, 2014

14.3K

Area of Science:

  • Organic Chemistry
  • Pericyclic Reactions

Background:

  • The Nazarov cyclization is a key reaction for synthesizing cyclopentenones.
  • Traditional methods often require harsh conditions or metal catalysts.

Purpose of the Study:

  • To develop a mild, metal-free catalytic system for the Nazarov cyclization.
  • To investigate the mechanism of iodine-catalyzed Nazarov cyclization.

Main Methods:

  • Utilizing molecular iodine (I2) as a catalyst for the Nazarov cyclization.
  • Employing various divinyl ketones, including aromatic systems.
  • Conducting reactions in both polar and apolar solvents.
  • Performing mechanistic studies to elucidate the catalytic pathway.

Main Results:

  • Successful synthesis of substituted cyclopentenones under mild, metal-free conditions.
  • Moderate to very good yields achieved with diverse substrates.
  • Mechanistic studies suggest activation via a halogen bond between iodine and the carbonyl group.
  • Ruled out Brønsted acid or iodonium ion catalysis as primary mechanisms.
  • Identified minimal side reactions like iodine addition or cis-trans isomerization.

Conclusions:

  • Molecular iodine is an effective catalyst for a metal-free Nazarov cyclization.
  • The reaction proceeds efficiently under mild conditions with broad substrate scope.
  • Halogen bonding plays a crucial role in activating the Nazarov system.