Gallium (III) triflate-catalyzed synthesis of heterocycles: quinoxalines, 1,5-benzodiazepines and their fluorinated derivatives

Background: The quinoxaline nucleus is a part of several antibiotics, such as echinomycin, levomycin and actinomycin, which are known to inhibit the growth of Gram-positive bacteria and are active against various transplantable tumors. Benzodiazepines are important classes of heterocycles that draw significant interest from the pharmaceutical industry because of their prominent therapeutic value, such as antiviral, antibacterial, anti-inflammatory, antiprotozoaval properties and also as kinase inhibitors. They have also been evaluated as anticancer, anthelmintic, antifungal and insecticidal agents. Results & conclusion: Quinoxalines, benzodiazepines and their fluorinated derivatives have been prepared in excellent yields from the corresponding diamines and diketones using gallium (III) triflate as an efficient and environmentally friendly catalyst, due to its stability, recyclability and minimal toxicity.