Photocatalyzed site-selective C(sp3)-H sulfonylation of toluene derivatives and cycloalkanes with inorganic sulfinates

The development of practical methods for the direct and selective C(sp(3))-H functionalization of hydrocarbons is an attractive topic in synthetic chemistry. Although the radical-mediated hydrogen atom transfer (HAT) process has shown considerable potential in such reactions, it still faces fundamental problems associated with reactivity and selectivity. Herein, we report a convenient and economic approach to site-selective C(sp(3))-H sulfonylation via photo-induced HAT catalysis. Employing a conjugated polycyclic quinone as a direct HAT photocatalyst, commercially available inorganic sulfinates as the sulfonylation source, copper triflate as an inexpensive oxidant, a variety of toluene derivatives and cycloalkanes were converted into biologically and synthetically interesting sulfone products under mild conditions. The mechanistic studies reveal that the reaction sequence involves direct HAT-induced radical formation and a subsequent copper-mediated organometallic process for the C-S bond formation. This method offers an appealing opportunity to furnish high value-added products from abundant hydrocarbon starting materials and inexpensive reagents. (C) 2022, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

We report a convenient and economic approach for the site-selective C(sp(3))-H sulfonylation of hydrocarbons via photo-induced hydrogen atom transfer (HAT) catalysis. This method converts toluene derivatives and cycloalkanes into biologically and synthetically interesting sulfone products, offering an opportunity to obtain high value-added products from abundant hydrocarbon starting materials and inexpensive reagents.