REGIOCONTROLLED IODOAMINOCYCLIZATION REACTION OF AN AMBIDENT NUCLEOPHILE MEDIATED BY BASIC METALLIC REAGENT

A new and general method of iodine-mediated cyclization reactions of a llyl or homoallyl carbamates, ureas, and amides was found to give N-cy clized products as single regioisomers. The present reaction proceeded in good yield through regiocontrol (N-cyclization > O-cyclization) an d the increase in the reactivity of an ambident nucleophile by a basic metallic reagent. The N-cyclization selectivity was remarkably affect ed by the additive employed. The iodoaminocyclization reaction of the homoallyl carbamates and ureas with a chiral center at the homoallylic position was found to proceed with high 1,3-cis- and 1,3-trans-select ivity, respectively.