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

Cycloaddition Reactions: Overview01:16

Cycloaddition Reactions: Overview

3.0K
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.
3.0K
Pericyclic Reactions: Introduction01:17

Pericyclic Reactions: Introduction

8.7K
Pericyclic reactions are organic reactions that occur via a concerted mechanism without generating any intermediates. The reactions proceed through the movement of electrons in a closed loop to form a cyclic transition state, where rearrangement of the σ and π bonds yields specific products.
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic...
8.7K
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

2.0K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
2.0K
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

2.6K
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.
2.6K
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation02:17

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

3.6K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.6K
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction01:16

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

11.1K
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.
11.1K

You might also read

Related Articles

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

Sort by
Same author

From ynones to alkynes <i>via</i> nickel catalyzed decarbonylative reconstructive C-C bond coupling.

Chemical science·2026
Same author

Synthesis of polymethylene-linked bis(cyclobutane-fused chromanones) mediated by gold photocatalysis.

Organic & biomolecular chemistry·2026
Same author

Effect of aluminum distribution in ZSM-22 zeolite on ethylene oligomerization.

Chemical communications (Cambridge, England)·2026
Same author

Cobalt/Photoredox Catalyzed Desymmetrization of Oxo and Azabicycles via Asymmetric Reductive Coupling With Alkynes.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)·2026
Same author

Guanidine-based azines from N-heterocyclic carbene (NHC)-derived selenoureas and diazo compounds: synthesis, structural diversification, and biological evaluation.

Organic & biomolecular chemistry·2026
Same author

Pulsed electrolysis enables unexpected lactonization of bicyclobutane carboxylic acids.

Chemical science·2026

Related Experiment Video

Updated: Nov 7, 2025

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
11:44

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Published on: March 20, 2014

25.6K

Conversion of Pd(I) off-cycle species into highly efficient cross-coupling catalysts.

Yaxu Liu1, Vladislav A Voloshkin1, Thomas Scattolin1

  • 1Department of Chemistry and Center for Sustainable Chemistry, Ghent University, Krijgslaan 281 (S-3), 9000, Ghent, Belgium. Steven.Nolan@UGent.be Catherine.Cazin@UGent.be.

Dalton Transactions (Cambridge, England : 2003)
|April 28, 2021
PubMed
Summary

Undesirable palladium complexes are easily converted into active pre-catalysts using inexpensive HCl. This study reveals the mechanism and factors influencing palladium dimer formation in cross-coupling reactions.

More Related Videos

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3
08:36

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3

Published on: April 7, 2023

1.3K
[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
09:12

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

9.5K

Related Experiment Videos

Last Updated: Nov 7, 2025

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
11:44

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Published on: March 20, 2014

25.6K
Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3
08:36

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3

Published on: April 7, 2023

1.3K
[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
09:12

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

9.5K

Area of Science:

  • Organometallic Chemistry
  • Catalysis
  • Organic Synthesis

Background:

  • Palladium complexes like [Pd2(μ-Cl)(μ-η3-R-allyl)(NHC)2] are often considered inactive off-cycle species in cross-coupling reactions.
  • Understanding the transformation of these species is crucial for optimizing catalytic processes.

Purpose of the Study:

  • To report a facile method for converting undesirable palladium complexes into active pre-catalysts.
  • To elucidate the mechanism of this transformation using DFT calculations.
  • To identify factors that promote or inhibit the formation of palladium(I) dimers.

Main Methods:

  • Conversion of [Pd2(μ-Cl)(μ-η3-R-allyl)(NHC)2] complexes to [PdCl(μ-Cl)(NHC)]2 pre-catalysts.
  • Mild reaction conditions: 40 °C, 1-2 hours in acetone.
  • Use of hydrochloric acid (HCl) as an oxidant and chloride source.
  • Density Functional Theory (DFT) calculations to investigate reaction pathways.

Main Results:

  • Successful and facile conversion of off-cycle palladium species into active pre-catalysts.
  • Reactions occur under mild, energy-efficient conditions.
  • DFT calculations suggest a mechanism involving two distinct pathways.
  • Insights gained into the formation of undesired palladium(I) dimers.

Conclusions:

  • A practical method for activating dormant palladium complexes has been developed.
  • The study provides a mechanistic understanding of the conversion process.
  • This work contributes to controlling palladium speciation and improving cross-coupling catalysis.