ИСТИНА

Symmetrical 2,6-dichloro-, 2,6-dibromo- and 3,5-dibromopyridines were investigated in the Pd(0)-catalyzed amination reactions with 1-(aminomethyl)adamantane. The possibility of the formation of the products of mono- and diamination was demonstrated. 2,6-Dichloropyridine was found to be the most convenient substrate for both transformations providing the highest yields. Pd-catalyzed amination of 2,3-dibromo-, 2,5-dibromo-, 3-bromo-2-chloro- and 5-bromo-2-chloropyridines with various adamantaneamines was studied. Almost in all reactions exclusive or prevailing substitution of the bromine atom in the presence of the chlorine atom was observed. Depending on the nature of dihalopyridine and amine Pd(0)/BINAP or Pd(0)/DavePhos catalytic system should be used. The best yields were generally achieved with 5-bromo-2-chloropyridine. Other dihalopyridines provided lower yields due to numerous side reactions.