Acid-Promoted Reaction of Trimethylsilylketene Bis(ethylthio)acetal with Imines. Synthesis of γ,γ-Bis(ethylthio)allylamines

Acid-catalyzed reaction of silylketene dithioacetal 1 with iminium salts or imines 3b,d-h gave the corresponding y,y-bis(ethylthio)allylamines 2a-h or 5b,d-h in generally high yields. Similar reactions of 1 with (salicylidene)-amines 6a-e afforded 4-amino-2,2-bis(ethylthio)chromans 8a-e in good to moderate yields.