Oxidative coupling reactions for the functionalisation of C–H bonds using oxygen
Oxidative coupling reactions enable the direct formation of a new bond from two C–H or heteroatom–H bonds without the need for special activating or leaving groups, and are thus interesting in the context of green chemistry. In order to attain high atom economy and sustainability, it is desirable to conduct these reactions catalytically with oxygen or air as terminal oxidant. Here, a representative overview of such reactions is given, illustrating the substrate scope and the variety of catalyst systems. Additionally, mechanisms and general strategies to utilise oxygen in such reactions are discussed.