Regio-controlled iodoaminocyclization reaction of an ambident nucleophile mediated by LiAl(Ot-Bu)₄

A new and general method of iodine-mediated cyclization reactions of unsaturated carbamates, ureas and amides which gives N-cyclized products as a single regio-isomer was achieved. The present reaction proceeds in good yield through regio-control of an ambident nucleophile by LiAl(Ot-Bu)₄, and the regio-control (N-attack vs O-attack) was also found to be remarkably affected by the additive employed.