Aniline synthesis turns to photochemistry to access challenging targets

Quoted: Shannon Stahl of the University of Wisconsin–Madison in the US, who developed a previous strategy to make aromatic rings from cyclohexanones, says that the new approach is ‘impressive in scope and compatibility with mild reaction conditions.’ He explains that earlier methods leveraged the use of oxygen as an oxidant and employed transition-metal catalysts to promote the dehydrogenation of the ring. ‘The present report promotes the dehydrogenation process by using light and a photoredox catalyst to generate a reactive radical, in combination with a cobalt catalyst that evolves hydrogen gas as the byproduct.’