Synthesis of -sulfenylated carbonyl compounds under metal-free conditions

An efficient synthesis of alpha-sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols under heating conditions is described. The method is characterized by mild conditions, simple operation, metal-free catalysis and good functional group tolerance. Mechanistic studies suggest that the reaction involves a radical pathway and an isomerization process. A highly efficient organocatalytic protocol for the synthesis of alpha-sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols is established. A wide range of alpha-sulfenylated carbonyl compounds were obtained in moderate to good yields.