I2-Promoted Synthesis of N-Heteroaromatic Benzothiazoles and 2,2'-Biquinolines via Deaminative Cyclization of Tertiary Amines

A straightforward I2-promoted Povarov multicomponent reaction strategy for the synthesis of N-heteroaromatic benzothiazole and 2, 2'-biquinolines was described. This methodology involved a one-pot two-step procedure, tandem iodination/Kornblum oxidation, and [4 + 2] condensation. This protocol was characterized by broad scope of substrates (49 examples, 31-80% yields), applicable for large-scale preparation, and downstream derivatization of the product. Photophysical property of the two classes of bisheteroaryl compounds were investigated. Based on the rotatable C-C bond, 2-(6-methylquinolin-2-yl)benzo[d]thiazole (4a) was successfully developed as a viscosity probe, which opened up new hopes and prospects for biomedical applications.