Radical click reaction to construct C–S bond via reductive coupling of phthalimide derivatives

Abstract

Click reactions have been highlighted as a powerful strategy for rapid synthesis of chemicals, as they revolutionize the approach in many fields in a short span of time with high reliability and efficiency. Herein, a novel method on radical click reaction for the synthesis of alkyl xanthates from the decarboxylative coupling of N-hydroxyphthalimide esters with N-xanthylphthalimides is presented. This reductive cross coupling was completed in 2 minutes at room temperature with easy operation. The primary, secondary and tertiary alkyl xanthate products were generated in good yields without the need for transition metal-catalyst. This strategy is characterized by the broad scope of common carboxylic acid and bioactive molecules, excellent functional group compatibility and speediness of implementation. Mechanism experiments demonstrated that the activation mode of the two phthalimide derivatives is independent but in similar processes, and the product was efficiently generated by the coupling pathway between the persistent sulfur radical and transient alkyl radical.