Radical click reaction for C–S bond construction via reductive coupling of phthalimide derivatives†

Abstract

Click reactions have been highlighted as a powerful strategy for the rapid synthesis of chemicals, revolutionizing approaches in many fields in a short span of time with high reliability and efficiency. Herein, a novel method for a radical click reaction is presented for the synthesis of alkyl xanthates via the decarboxylative coupling of N-hydroxyphthalimide esters with N-xanthylphthalimides. This reductive cross-coupling was completed in 2 min at room temperature with simple operation. Primary, secondary and tertiary alkyl xanthate products were obtained in good yields without the need for a transition metal catalyst. This strategy was characterized by a broad scope encompassing common carboxylic acid and bioactive molecules, excellent functional group compatibility and rapid implementation. Mechanistic experiments demonstrated that the activation modes of the two phthalimide derivatives were independent yet proceeded through similar processes, and the product was efficiently generated via a coupling pathway between a persistent sulfur radical and a transient alkyl radical.