Construction of sulfur-containing N -vinylimides: N -addition of imides to propargyl sulfonium salts.

An N -addition reaction between imides and propargyl sulfonium salts was developed to afford sulfur-containing N -vinylimides with moderate to excellent yields. Under the activation of NaOAc·3H 2 O, imides could undergo deprotonation and propargyl sulfonium salts could isomerize to allenic sulfonium salts. The N -nucleophilic attack initiates the reaction and gives the desired products. Various imides, including arylimides, aliphatic imides and N -(arylsulfonyl) alkyl acylamides, and even bioactive saccharin, thalidomide and pomalidomide could provide organosulfur N -vinylimides compounds. The simple, mild and metal-free reaction conditions, the broad scope of substrates, gram-scale synthesis and convenient transformation embody the synthetic superiority of this process.