Copper-Catalyzed Tandem Aerobic Oxidative Cyclization for the Synthesis of Polysubstituted Quinolines via C(sp³)/C(sp²)–H Bond Functionalization

Abstract

One-pot Cu-catalyzed tandem aerobic oxidative cyclization for the synthesis of quinolines from 2-vinylanilines/2-arylanilines and 2-methylquinolines via C(sp)-H/C(sp)-H bond functionalization has been developed. Dioxygen as an ideal oxidant has been employed for this transformation. The substrates bearing various functional groups perform well in this process and generate the desired products in moderate to good yields.

Recent synthetic efforts in the preparation of 2-(3,4)-alkenyl (aryl) quinoline molecules towards anti-kinetoplastid agents

“…Some 6(7)-(di)substituted 4-phenylquinolines were An interesting synthesis of potential bioactive 4-aryl-2-(quinolinyl-2)-quinolines through Cu-catalysed cascade oxidative cyclization reaction of 2-(1-phenylvinyl)anilines and 2methylquinolines has been reported by Yan and colleagues in 2017. 146 Remarkably, since 2008 there has been an extraordinary increment in the number of reported procedures describing the construction of quinolines that have a variety of functional groups at different positions, especially 2,4-diphenylquinolines. These quinoline derivatives are very important and promising molecules for the synthesis of OLED materials, crucial ligands in the formation of other conjugated molecules with enhanced optoelectronic properties.…”

Recent Advances on Copper-Catalyzed C–C Bond Formation via C–H Functionalization

“…For example, Pang and co-workers recently developed the synthesis of polysubstituted quinolone derivatives under aerobic conditions via oxidative cyclization of 2-vinylanilines or 2-arylanilines and 2-methylquinolines (Scheme 15). 48…”

A review on transition-metal mediated synthesis of quinolines

“…Further, the protocol was successfully extended with 2-methyl-1,2,3,4-tetrahydroquinoline to deliver desired products in moderate yields. 32 Mondal et al, has disclosed an unprecedented solvent free, CuBr-ZnI 2 combo-catalyzed Cu 1 − Cu III switching strategy to generate substituted quinolines through sp2 C-H activation of highly electron-rich arenes. In this protocol, substituted aniline (35), aldehydes (41), and terminal alkynes (40) were rapidly coupled to generate the desired quinoline (42) framework through cyclization of the c≡≡c bond (Scheme 4).…”