Related Experiment Video
Updated: Jul 18, 2026

Synthesis of Terpolymers at Mild Temperatures Using Dynamic Sulfur Bonds in Poly(S-Divinylbenzene)
Published on: May 20, 2019
Highly activated vinyl hydrogen in a significantly twisted styrene
Hajime Mori1, Takafumi Matsuo, Yasunori Yoshioka
1School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan. hmori@wakayama-kg.go.jp
Researchers discovered vinyl hydrogens in twisted styrene derivatives are more reactive than benzylic hydrogens. This reactivity stems from unique orbital interactions in these sterically hindered molecules.
Area of Science:
- Organic Chemistry
- Physical Chemistry
Background:
- Benzylic hydrogens are typically known for their high reactivity due to resonance stabilization.
- Styrene derivatives offer a platform for studying vinyl hydrogen reactivity.
Purpose of the Study:
- To report a novel instance of vinylic hydrogen exhibiting greater reactivity than benzylic hydrogen.
- To investigate the relationship between the degree of molecular twist and vinyl hydrogen reactivity in styrene derivatives.
Main Methods:
- Treatment of twisted styrene derivatives with a strong base.
- Quenching the reaction with deuterium oxide (D2O) to confirm hydrogen abstraction.
- Spectroscopic analysis to characterize the products and assess reactivity.
Main Results:
- A novel example where vinylic hydrogen is more reactive than benzylic hydrogen was identified.
- The reactivity of vinyl hydrogens directly correlates with the magnitude of the twist in the styrene derivative.
- Highly activated vinyl hydrogens were observed in sterically hindered, twisted styrene systems.
Conclusions:
- The enhanced reactivity of vinylic hydrogens in twisted styrenes is attributed to a novel orbital interaction.
- This interaction involves the pi(*) orbital of the benzene ring and the pi(*) orbital of the vinylic C-H bond.
- The study provides new insights into the activation of C-H bonds in strained organic molecules.
More Related Videos
06:49Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
Published on: April 22, 2016
09:17Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes
Published on: January 30, 2015
Related Concept Videos
Polymer Classification: Stereospecificity
Stability of Conjugated Dienes
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
Radical Chain-Growth Polymerization: Mechanism
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Electrophilic Addition to Alkynes: Hydrohalogenation
Radical Chain-Growth Polymerization: Chain Branching