Visible light mediated organocatalytic dehydrogenative aza-coupling of 1,3-diones using aryldiazonium salts

An efficient protocol for diazenylation of 1,3-diones under photoredox conditions is presented herein. C-N bond forming Csp3-H functionalization of cyclic and alkyl diones by unstable aryl diazenyl radicals is achieved through reaction with aryldiazonium tetrafluoroborates by organocatalysts under visible light irradiation. The reaction has wide substrate scope, gives excellent yields, and is also efficient in water as a green solvent. This method provides an easy access to aryldiazenyl derivatives that are useful key starting materials for the synthesis of aza heterocycles as well as potential pharmacophores.

Automated summary

An efficient photoredox protocol for the diazenylation of 1,3-diones is presented. C-N bond formation through Csp3-H functionalization of cyclic and alkyl diones by unstable aryl diazenyl radicals is achieved using aryldiazonium tetrafluoroborates and organocatalysts under visible light irradiation. The reaction has broad substrate scope, high yields, and can be performed efficiently in water as a green solvent. This method provides easy access to aryldiazenyl derivatives, which are valuable starting materials for the synthesis of aza heterocycles and potential pharmacophores.