Metal-Free Synthesis of 2-Fluoroalkylated Quinolines Using Polyfluoroalkanoic Acids as Direct Fluorine Sources.

A novel [5 + 1] cyclization of 2-vinylanilines with polyfluoroalkanoic acids under catalyst- and additive-free conditions was successfully implemented. The approach directly employs very low-cost and readily available polyfluoroalkanoic acids as both C1 synthons and fluoroalkyl building blocks. This method provides concise access to diverse 2-fluoroalkylated (CF3, C2F5, C3F7, CF2H, CF2Cl, and CF2Br) quinolines in good yields with excellent functional group tolerance in high yield on a gram scale.