Regiocontrolled Iodoaminocyclization Reaction of an Ambident Nucleophile Mediated by Basic Metallic Reagent.
A new and general method of iodine-mediated cyclization reactions of allyl or homoallyl carbamates, ureas, and amides was found to give N-cyclized products as single regioisomers. The present reaction proceeded in good yield through regiocontrol (N-cyclization > O-cyclization) and the increase in the reactivity of an ambident nucleophile by a basic metallic reagent. The N-cyclization selectivity was remarkably affected 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-selectivity, respectively.
Fujita
Masao
M
Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-03, Japan.
Kitagawa
Osamu
O
Suzuki
Takashi
T
Taguchi
Takeo
T