The Palladium-Catalyzed Heteroarylation of Adamantylalkyl Amines with Dihalogenopyridines: Scope and Limitations

Palladium-catalyzed heteroarylation of adamantylalkyl amines characterized by different steric hindrances at the amino group was carried out using 2,3-, 2,5-, 2,6-, and 3,5-dihalogenopyridines. The dependence of the results of the coupling on the nature of the halogen atoms (bromine, chlorine), their position in the pyridine ring, and on the structure of adamantylalkyl amines was investigated. The application of dichloropyridines or bromochloropyridines was shown to be advantageous over the use dibromopyridines in many cases. Selective substitution of bromine atom in positions 3 and 5 in the presence of chlorine atom in position 2 of the pyridine ring was observed. The possibility of N,N-diheteroarylation of adamantane-containing amines with 2,5-dihalogenopyridines was shown, and diamination of 2,6- and 3,5-dihalogenopyridines was demonstrated.