Synthesis of Indolo[3,2‐ bb ]carbazoles viavia an Anomeric‐Based Oxidation Process: A Combined Experimental and Computational Strategy

摘要

> Indolo[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 1 H ‐indole and various aldehydes in the presence of a catalytic amount of N ,2‐dibromo‐6‐chloro‐3,4‐dihydro‐2 H ‐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.