Sulfonic acid functionalized imidazolium salts/ FeCl3 as novel and highly efficient catalytic systems for the synthesis of benzimidazoles at room temperature

AbstractIonic liquid 3-methyl-1-sulfonic acid imidazolium chloride/ FeCl3, as well as ionic liquid 1, 3-disulfonic acid imidazolium chloride/ FeCl3 catalytic systems, efficiently catalyzes the condensation of benzene-1, 2-diamine with aromatic aldehydes in the presence of atmospheric air as a green oxidant in ethyl acetate at room temperature to afford benzimidazole derivatives in high yields and in short reaction times. The reaction is also efficiently performed when carboxylic acids are used instead of aldehydes

Synthesis of Indolo[3,2-b]carbazoles via an Anomeric-Based Oxidation Process: A Combined Experimental and Computational Strategy

NoIndolo[3,2-b]carbazole is a molecule of great biological significance, as it is formed in vivo after consumption of cruciferous vegetables. The reaction of 1H-indole and various aldehydes in the presence of a catalytic amount of N,2-dibromo-6-chloro-3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine-7-sulfonamide 1,1-dioxide as an efficient and homogeneous catalyst in acetonitrile at 50°C produces 6,12-disubstituted 5,7-dihydroindolo[2,3-b]carbazole with an in good to excellent yield. The presented technique offers a fast and robust method, by the use of inexpensive commercially available starting materials toward 6,12- disubstituted 5,7-dihydroindolo[2,3-b]carbazole. A new anomeric-based oxidation was kept in mind for the final step of the indolo[2,3-b]carbazoles synthesis. The suggested anomeric-based oxidation mechanism was supported by experimental and theoretical evidences.The Grant of Allameh Tabataba’i’s Award, Grant Number: BN09