Photo‐Initiated Cobalt‐Catalyzed Radical Olefin Hydrogenation
Sier Sang, Tobias Unruh, Serhiy Demeshko, Luis I. Domenianni, Nicolaas P. van Leest, Philipp Marquetand, Felix Schneck, Christian Würtele, Felix J. de Zwart, Bas de Bruin, Leticia González, Peter Vöhringer, Sven Schneider
Abstract
Abstract Outer‐sphere radical hydrogenation of olefins proceeds via stepwise hydrogen atom transfer (HAT) from transition metal hydride species to the substrate. Typical catalysts exhibit M−H bonds that are either too weak to efficiently activate H 2 or too strong to reduce unactivated olefins. This contribution evaluates an alternative approach, that starts from a square‐planar cobalt(II) hydride complex. Photoactivation results in Co−H bond homolysis. The three‐coordinate cobalt(I) photoproduct binds H 2 to give a dihydrogen complex, which is a strong hydrogen atom donor, enabling the stepwise hydrogenation of both styrenes and unactivated aliphatic olefins with H 2 via HAT.