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![[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)
[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
Photocatalytic C-I Borylation via Halogen Bond-Enabled Electron Transfer: A Strategy for Generating Aryl Radicals
Eiji Yamaguchi1,2, Tomohiro Yasuda1, Akichika Itoh1,2
1Laboratory of Pharmaceuticals Synthetic Chemistry, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
Abstract:
We report the development of triarylphenol-based photocatalysts that promote C-I bond borylation via halogen bonding (XB) interactions under visible-light irradiation. Traditional phenol system reactions often suffer from phenoxyl radical instability, limiting their catalytic utility. To overcome this issue, we designed sterically and electronically tuned triarylphenols that stabilize radical intermediates while maintaining high photoreactivity. Systematic evaluation revealed that 2,4,6-triphenylphenol efficiently facilitates photoinduced electron transfer (PET) and suppresses undesired side reactions such as phenol decomposition. The optimized reaction conditions enabled a broad substrate scope, showing efficient arylboronic ester formation. Density functional theory calculations confirmed the formation of XB complexes with charge-transfer character, providing mechanistic support for the PET pathway. This work shows the potential of rationally designed phenols as XB acceptors and offers a sustainable approach for C-I bond functionalization.
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