We report a metal-free photocatalytic process for arene C-H functionalization that employs an acridinium-type catalyst and produces dihydrogen as the only by-product. Throughout the catalytic cycle, the catalyst acts as an oxidising, a hydrogen atom transfer, and a proton-reducing agent enabling a cross-dehydrogenative transformation without the need for external oxidants. The reaction is conveniently performed using visible light and the high oxidation potential of the catalyst allows to engage even electron-deficient arenes as substrates. The catalytic mechanism disclosed herein has a potential to become a general logic for the development of various cross-dehydrogenative reactions adaptable for use in pharmaceutical and material sciences.
PHOTOREDOX MANIFOLD FOR DEHYDROGENATIVE COUPLING USING PROTONS AS THE SOLE OXIDANTS
Jonas Žurauskas1, Paulius Vaickūnas1, Gustautas Snarskis3, Gediminas Kreiza2, Steponas Raišys2, Mantas Šimėnas2, Vidmantas Kalendra2, Kęstutis Zakarauskas4, Barbara Chatinovska1, Karolis Kazlauskas2, Edvinas Orentas1
1 Department of Organic Chemistry, Vilnius University; Vilnius, Naugarduko 24, LT-03225, Lithuania
2 Institute of Photonics and Nanotechnology, Vilnius University, Vilnius, Saulėtekio av. 3, LT-10257, Lithuania
3 Biomatter, Business Stadium West, Rinktinės g. 5-101, LT-09234 Vilnius, Lithuania
4 Laboratory of Combustion Processes, Lithuanian Energy Institute, Breslaujos 3, LT-44403, Kaunas, Lithuania