Electron and Hole Catalysis via Reductant and Oxidant Upconversion: The Case of 1,2-disila-3,5-cyclohexadiene

Beauty Chabuka^a, Leah Kuhn^a, Mikhail A. Syroeshkin^b, Igor V. Alabugin^a

aDepartment of Chemistry & Biochemistry, Florida State University, Tallahassee, FL, 32306
bN.D. Zelinsky Institute of organic chemistry, 119991, Moscow, Russia

The phenomenon of reductant upconversion describes a seeming chemical paradox in which an exergonic reaction converts a weak reductant into a stronger reductant. A similar concept has also been developed for oxidant (hole) upconversion. Such redox upconversion processes provide the key to using electrons and holes as true catalysts for chemical transformations because they allow for chain propagation through electron transfer.

Reductant upconversion has been reported for organic compounds containing N – O, O – O, C – N, S – N, and even C – C bonds. This work explores the possibility of redox upconversion in electrocatalytic transformations of 1,2-disila-3,5-cyclohexadiene. We show that, even though both oxidative and reductive reactions involve Si-Si bond scission, as long as these processes rely on electron and hole upconversion, they have to proceed via different mechanisms.