Metal-Free Multicatalytic Decarbonylation of Aldehydes Driven by Light

A metal-free dual photo- and organocatalytic decarbonylation of aliphatic aldehydes is described for the first time. On the one hand, a wide range of tertiary aldehydes are smoothly decarbonylated thanks to the combination of thioxanthone as photocatalyst and diphenyl disulfide as organocatalyst. On the other hand, by simply using 4-CzIPN as photocatalyst instead of thioxanthone, various secondary aldehydes readily undergo decarbonylation in an orthogonal manner, via the in situ formation of 1,4-dihydropyridines. Both methodologies are compatible with various functional groups and are readily applied to the decarbonylation of complex molecules.