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

Cationic Chain-Growth Polymerization: Mechanism00:57

Cationic Chain-Growth Polymerization: Mechanism

2.8K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.8K
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

2.9K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.9K
Anionic Chain-Growth Polymerization: Overview01:20

Anionic Chain-Growth Polymerization: Overview

2.5K
The polymerization process that involves carbanion as an intermediate is called anionic polymerization. It is also a type of addition or chain-growth polymerization. Anionic polymerization gets initiated by a strong nucleophile such as an organolithium or a Grignard reagent. The most commonly used initiator for anionic polymerization is butyl lithium. Monomers involved in anionic polymerization must possess a vinyl group bonded to one or two electron-withdrawing groups. For instance,...
2.5K
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction01:16

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

12.1K
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.
12.1K
Anionic Chain-Growth Polymerization: Mechanism01:04

Anionic Chain-Growth Polymerization: Mechanism

2.4K
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael...
2.4K
Cycloaddition Reactions: MO Requirements for Photochemical Activation01:12

Cycloaddition Reactions: MO Requirements for Photochemical Activation

2.6K
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.
2.6K

You might also read

Related Articles

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

Sort by
Same author

Hydrazine-mediated carbonyl-alkyne/allene reductive olefination.

Nature communications·2026
Same author

Ynamide-Mediated Ketone Synthesis.

Organic letters·2026
Same author

Sequence Display enables large-scale sequence-activity datasets for rapid protein evolution.

Nature biotechnology·2026
Same author

One-Step-Three-Ring Propellanation Reaction of Yne-Vinylcyclobutanones Catalyzed by Nickel: Reaction Development, Mechanism, and Formal Synthesis of Modhephene.

Journal of the American Chemical Society·2026
Same author

Development and Mechanism of Rh-Catalyzed Keto-(5 + 1 + 2) Reaction of Keto-Vinylcyclopropanes and CO, and Answering Why Rh-Catalyzed Keto-(5 + 2) Reaction of Keto-Vinylcyclopropanes Fails.

Journal of the American Chemical Society·2026
Same author

Mechanistic Study of Cycloisomerization of 1,7-Allenenes and Guidance to Develop a [2 + 1 + 2] Reaction of 1,7-Allenenes with CO for Accessing <i>cis</i>- and <i>trans</i>-5/5 Skeletons.

Journal of the American Chemical Society·2026
Same journal

Switchable <i>N</i>-Haloethylation and C-H Halogenation of NH-Enaminones with 1,2-Dihaloethanes.

The Journal of organic chemistry·2026
Same journal

Lewis Acid-Catalyzed Cascade Ring Expansion and Intramolecular Friedel-Crafts Type Cyclization of α-Dithioacetyl Propargyl Alcohols: Access to <i>S</i>,<i>S</i>-Heterocycle-Fused Benzofulvenes and 3-Benzylidene-1-indanones.

The Journal of organic chemistry·2026
Same journal

Photocatalytic Decarboxylation of Carboxylic Acids to Construct Unnatural Amino Acids and Peptides-Containing Piperidine Rings.

The Journal of organic chemistry·2026
Same journal

TABF as a Double Proton Sponge: Steric Preorganization versus Antiaromatic Destabilization.

The Journal of organic chemistry·2026
Same journal

Copper-Catalyzed Radical Sulfonylative Cyclization of <i>o</i>-Vinylanilides with Sulfonyl Chlorides for the Synthesis of Sulfonylated 4<i>H</i>-Benzo[<i>d</i>][1,3]oxazines.

The Journal of organic chemistry·2026
Same journal

Photochemical Ni-Catalyzed Cross-Coupling of Aryl Bromides with Hydrazides.

The Journal of organic chemistry·2026
See all related articles

Related Experiment Video

Updated: Jan 14, 2026

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
12:19

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization

Published on: November 29, 2018

8.9K

Ynamide Protonation-Initiated N-Heteropolyene Cyclization.

Han Chen1,2, Chen-Long Li3, Can Liu4

  • 1Affiliated Cancer Hospital, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, China.

The Journal of Organic Chemistry
|October 20, 2025
PubMed
Summary
This summary is machine-generated.

A new method uses protonation of ynamide-initiated polyene cyclization to create complex N-containing polycyclic molecules with chiral centers. This approach achieves excellent stereoselectivity, simplifying the synthesis of valuable compounds.

More Related Videos

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
07:06

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Published on: February 16, 2020

8.5K
Constructing Cyclic Peptides Using an On-Tether Sulfonium Center
07:11

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center

Published on: September 28, 2022

3.1K

Related Experiment Videos

Last Updated: Jan 14, 2026

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
12:19

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization

Published on: November 29, 2018

8.9K
A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
07:06

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Published on: February 16, 2020

8.5K
Constructing Cyclic Peptides Using an On-Tether Sulfonium Center
07:11

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center

Published on: September 28, 2022

3.1K

Area of Science:

  • Organic Chemistry
  • Synthetic Chemistry
  • Stereoselective Synthesis

Background:

  • N-containing polycyclic frameworks with chiral centers are crucial in natural products and bioactive molecules.
  • Stereoselective construction of these complex frameworks is a significant synthetic challenge.

Purpose of the Study:

  • To develop an efficient and stereoselective method for synthesizing complex N-containing polycyclic skeletons.
  • To overcome limitations of existing multi-step strategies for accessing these structures.

Main Methods:

  • Utilized ynamide-initiated polyene cyclization triggered by protonation.
  • Employed Density Functional Theory (DFT) calculations to elucidate the reaction mechanism.

Main Results:

  • Successfully constructed complex N-containing polycyclic frameworks with excellent stereoselectivity from linear precursors.
  • Identified a nonclassical carbocation intermediate with a cyclopropane ring as key to diastereoselectivity.

Conclusions:

  • Protonation of ynamide-initiated polyene cyclization offers a powerful strategy for stereoselective synthesis.
  • The mechanistic insights from DFT calculations aid in understanding and controlling the stereochemical outcome.