Related Experiment Video
Updated: Aug 18, 2026

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Cyclization or hydrogen migration: theoretical study and experimental evidence on the reactivities of unsaturated
Qian Chen1, Meihua Shen, Yu Tang
1Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, P. R. China.
Abstract:
[reaction: see text] Theoretical calculations (B3LYP/6-31G) backed up by deuterated experiments reveal that the N-substituents (R) play a crucial role in determining the reaction pathways of unsaturated amidyl radicals. With the increase of the bulkiness of N-alkyl group, the activation energy for 6-exo cyclization increases steadily, while the activation energy for 1,5-H abstraction remains almost unchanged. Therefore, cyclization occurs exclusively when R is H while 1,5-H migration occurs exclusively when R is t-Bu.
Related Concept Videos
Radical Reactivity: Overview
Radical Reactivity: Electrophilic Radicals
Radical Chain-Growth Polymerization: Chain Branching
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Radical Reactivity: Intramolecular vs Intermolecular
Radical Reactivity: Nucleophilic Radicals

