Arylation of Adamantanamines: XI. Comparison of the Catalytic Efficiency of Palladium and Copper Complexes in Reactions of Adamantanamines with Fluorinated 2-Bromopyridines

A comparative study of the catalytic efficiency of Pd(0) and Cu(I) complexes in the reactions of adamantanamines with fluoro- and trifluoromethyl-substituted 2-bromopyridines was carried out using previously optimized catalytic systems. It was shown that in the absence of steric hindrances in the starting compounds, the copper and palladium catalysts were comparable in efficiency. In some cases, the yields of the target N-heteroarylated compounds in the copper-catalyzed reactions were even higher, which can be explained by the formation of N,N-diheteroarylated by-products under palladium-catalyzed conditions. At the same time, ortho-fluorine- and ortho-trifluoromethyl-substituted 2-bromopyridines successfully react exclusively under palladium catalysis.