Synthesis of Tricyclic Nitrogen-containing Heterocycles by Palladium-catalyzed Cyclization of 2-Alkenyl-N-(o-iodobensoyl)- and 2-Alkenyl-N-(o-iodophenylacetyl)pyrrolidines

Abstract

The palladium-catalyzed cyclization of the 2-alkenyl-N-(0-iodobenwy1)and 2-alkenyl-N-(0-iodophenylacety1)pynolidis gave the tricyclic nitrogencontaining heterocycles.As pan of our continuing studies towards the synthesis of optically active cephalotaxine,l we recently examined the tributyltin hydride-mediated cyclization of N-(o-bmmobenwyl)-2-@rop2enyl)-2-vinylplidine (I) in the hope that a mute to 5 or 6 might result.In fact, this particular mode of cyclization was not observed but the 7azabicyclo[2.2.I]heptane (3) (41% as a mixture of exo and endo isomers in a ratio of 21) and the 8-azabicyclo-[3.2.l]octane systems (4) (16%), along with the reduction product (13%).were obtained.This reaction