Selenium-Mediated Cyclization Reaction of 2-Vinylanilines with/without Isonitriles: Efficient Synthesis of 2-Aminoquinoline/ 3-Aryl-1H-indole Derivatives

Herein, we report a non-metal strategy for cyclization reactions of 2-vinylanilines with/without isonitriles to synthesize 2-aminoquinoline and 3-aryl-1H-indole derivatives. A series of 2-aminoquinolines were afforded in good to excellent yields in a direct, facile, and efficient approach by Se-catalyzed isocyanide insertion with 2-vinylanilines under an air atmosphere. This reaction not only used low toxicity Se as the catalyst, isocyanobenzene substrates were compatible too compared to previous report. Meanwhile, an intramolecular cyclization of 2-vinylanilines was developed to give 3-aryl-1H-indoles in moderate to good yields by using SeO2 as oxidant.