Visible-light-induced bifunctionalisation of (homo)propargylic amines with CO2 and arylsulfinates

An unprecedented carboxylative sulfonylation of (homo)propargyl amines with CO2 and sodium arylsulfinates under visible light irradiation has been developed with high efficiency. This ruthenium-catalysed photochemical protocol offers broad substrate scope giving 2-oxazolidinones and 2-oxazinones bearing alkyl sulfones in good yields under ambient reaction conditions. An in situ double bond isomerisation occurs in tandem. A mechanistic rationale for these radical-initiated carboxylative cyclisations involving sulfinyl radicals is presented, supported by control and quenching experiments.

Automated summary

An unprecedented carboxylative sulfonylation reaction of (homo)propargyl amines with CO2 and sodium arylsulfinates under visible light irradiation has been developed, exhibiting high efficiency. The ruthenium-catalyzed photochemical protocol offers a wide range of substrates, resulting in good yields of 2-oxazolidinones and 2-oxazinones bearing alkyl sulfones under ambient reaction conditions. In situ double bond isomerization occurs in tandem. The mechanism of these radical-initiated carboxylative cyclizations involving sulfinyl radicals is explained based on control and quenching experiments.