Remote alkylation of N-(quinolin-8-yl)benzamides with alkyl bromides via ruthenium(II)-catalyzed C-H bond activation

A ruthenium(II) catalyzed remote C-5 alkylation of the quinoline ring of N-(quinolin-8-yl)benzamides with alkyl bromides via C-H bond activation is described. Various substituted N-(quinolin-8-yl)benzamides reacted with tertiary or secondary or primary alkyl bromides giving the alkylated products in good to moderate yields. Herein, the ruthenium catalyzed remote C-5 alkylation is effected via aromatic C-H bond activation as a key step. It has been proved by the deuterium labelling studies and mechanistic investigations.