Cascade Reaction of Propargyl Amines with AgSCF₃, as Well as One-Pot Reaction of Propargyl Amines, AgSCF₃, and Di-<i>tert</i>-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-<i>tert</i>-butyl peroxide and AgSCF₃ under reflux to generate novel allenyl trifluoromethylthioether compounds in moderate to good yields via a “one-pot” three-step process