Photocatalytic coupling of electron-deficient alkenes using oxalic acid as a traceless linchpin

Reductive alkene cross-coupling represents a straightforward strategy for the construction of C–C bonds from readily available alkene feedstocks. A one-pot protocol, utilizing oxalic acid as a traceless linchpin, has been developed to achieve direct cross-coupling of electron-deficient alkenes. The overall process is a two-step transformation involving hydrocarboxylation followed by decarboxylative cross-coupling. A dual-photocatalyst system is crucial for success and promotes the two reaction steps synergistically. This reaction supports the efficient synthesis of bioactive molecules. Photoredox catalysis provides an easy and mild pathway for the generation of a CO2 radical anion from oxalic acid, which paves the way for the broad utilization of this reactive intermediate in the synthesis of fine chemicals.