Facile beta-alkyl and beta-hydride elimination in the nickel-catalyzed annulation of o-iodophenyl ketones and aldehydes with bicyclic alkenes

[reaction: see text] o-Iodoaryl aldehydes react with bicyclic alkenes in the presence of NiBr(2)(dppe) and Zn powder in acetonitrile at 80 degrees C undergoing annulation to give polycyclic ketone derivatives. Surprisingly, o-iodoaryl alkyl ketones also react with bicyclic alkenes to form polycyclic ketones with structures the same as those from the corresponding o-iodoaryl aldehydes.