Cascade Reaction of Propargyl Amines with AgSCF3, as Well as One-Pot Reaction of Propargyl Amines, AgSCF3, and Di-tert-butyl Peroxide: Access to Allenyl Thiocyanates and Allenyl Trifluoromethylthioethers

An efficient cascade reaction of propargyl amines with AgSCF3 and KBr is developed, affording allenyl thiocyanates at room temperature in high yields. This transformation proceeds via the in situ formation of isothiocyanate intermediates, followed by a [3,3]-sigmatropic rearrangement. The resulting allenyl thiocyanates bearing 3-(electro-donating phenyl) substitutions without isolation can then be reacted with di-tert-butyl peroxide and AgSCF3 under reflux to generate novel allenyl trifluoromethylthioether compounds in moderate to good yields via a “one-pot” three-step process.