Arylation of adamantanamines: VII. Copper(I)-catalyzed N-heteroarylation of adamantane-containing amines with halopyridines

Copper(I)-catalyzed N-heteroarylation of a wide series of adamantane-containing amines with 2-bromo- and 2- and 3-iodopyridines was studied. The corresponding N-pyridyl derivatives were formed in all cases, but iodopyridines were considerably more reactive. The best results were obtained with the catalytic system CuI-2-(2-methyl-1-oxopropyl)cyclohexanone-DMF which ensured up to 90% yield of the target products. The yield of N-pyridyl derivatives also depended on the steric environment of the amino group in the initial adamantane-containing amine. The yield of the heteroarylation products can be considerably increased using excess iodopyridine. The reaction of 2-(adamantan-1-yl)ethanamine with 2,6-dibromopyridine successfully afforded the corresponding diamine, and N,N′-dipyridyl derivatives were obtained in high yields from 2,2′-(adamantane-1,3-diyl)diethanamine.