The iodine-promoted cyclization of various N-(2-CF3-2-NHTs)ethylbenzimidazoles and N-(2-CF3-2-NHTs)ethylindoles proceeded smoothly and efficiently under mild basic conditions. This reaction did not require transition metals and afforded the corresponding CF3-dihydroimidazobenzimidazoles and CF3-dihydroimidazoindoles in 85–93% and 42–82% yields, respectively.
