Photoredox Generation of Isothiouronyl Radical Cations: A New Platform in Covalent Radical Catalysis

Angew Chem Int Ed Engl. 2022 Aug 8;61(32):e202205596. doi: 10.1002/anie.202205596. Epub 2022 Jun 28.

Abstract

Thiyl radicals offer unique catalytic patterns for the direct covalent activation of alkenes. However, important limitations in terms of structural diversity and handling have hampered the routine use of thiyl radicals in covalent radical catalysis. Herein, we report a new class of cationic sulfur-centered radicals to achieve covalent radical catalysis. Their generation from highly modular thioureas by photoredox catalysis make their utilization very simple and reliable. The synthetic potential and the versatility of the catalytic system were finally evaluated in a (3+2)-radical cascade between vinylcyclopropanes and olefins.

Keywords: Covalent Catalysis; Photocatalysis; Radical Ions; Thioureas; Thiyl Radicals.