Related Experiment Video
Updated: Jan 15, 2026

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
Published on: April 22, 2016
Cation radical-mediated semi-pinacol and n+2 ring expansions via organic photoredox catalysis
Brandon B Fulton1, Connor T Owen1, David A Nicewicz1
1Department of Chemistry, University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599-3290 USA nicewicz@email.unc.edu.
Abstract:
In this report, we disclose a photoredox-catalyzed cation radical-mediated semi-pinacol (CRM-SP) rearrangement along with a similar, but mechanistically distinct, n+2 ring expansion with protocols for obtaining either dearomatized or rearomatized products. We present a substrate scope of >30 entries largely focused on the ring expansion of easily appended cyclobutanols and targeting medicinally relevant scaffolds, highlighting the utilization of the methodology for diversification. Gram scale reactions in batch and continuous flow were investigated. Additionally, the mechanism is probed both experimentally and computationally with results suggesting a substrate-dependent set of pathways featuring either (A) a concerted 1,2-shift or (B) a sequence of proton-coupled electron transfer (PCET), β-scission, Giese addition, and terminal hydrogen atom transfer (HAT).
Related Concept Videos
Radical Formation: Addition
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
Radical Reactivity: Overview
Radical Reactivity: Nucleophilic Radicals
Radical Reactivity: Intramolecular vs Intermolecular
Radical Formation: Elimination
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
![[DPEPhosbcpCu]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)
