Related Experiment Video
Updated: Oct 1, 2026
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Photochemistry of benzotriazole: an unprecedented tautomer-selective intermolecular [2+2] photocycloaddition
Kevin I Booker-Milburn1, Paul M Wood, Richard F Dainty
1School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK. k.booker-milburn@bristol.ac.uk
Abstract:
[reaction: see text]. Irradiation of benzotriazole with a variety of maleimide derivatives leads to the stereo- and regioselective formation of aryl [2 + 2] photocycloaddition products. Further studies with 2-alkyl benzotriazole derivatives indicates that in the case of the parent benzotriazole this cycloaddition proceeds selectively via the 2H-tautomer.
Related Concept Videos
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Cycloaddition Reactions: Overview
Cycloaddition Reactions: MO Requirements for Thermal Activation
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Nucleophilic Aromatic Substitution: Elimination–Addition
![[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)