In this work we examined the functionalization of C–H bonds on 5,6-diphenyl-2,3-dihydropyrazine substrates with aryl halides in the presence of ruthenium catalyst. The goal was to find out which products could be obtained and to optimize the reaction conditions, where the reaction would result in good selectivity and high yields. All the reactions were performed with in situ generated ruthenium(II) catalytic systems, which were optimized by trying out various ligands. Reactions were also optimized by using different solvents and adjusting reaction time and temperature. Several different arylating reagents were also used. Because of the presence of the imino directing group and nonplanar structure of 5,6-diphenyl-2,3-dihydropyrazine derivatives arylation proceeded on the ortho positions of one or both benzene rings.
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