Scope and regioselectivity of the 1,3-dipolar cycloaddition of azides with methyl 2-perfluoroalkynoates for an easy, metal-free route to perfluoroalkylated 1,2,3-triazoles

1,3-Dipolar cycloadditions of methyl 2-perfluoroalkynoates with various azides have been examined, leading to a simple metal-free synthetic protocol for the synthesis of perfluoroalkylated 1,2,3-triazoles. The regiochemical results demonstrated that the cycloaddition was controlled by FMO (the frontier molecular obitals) interaction and steric hindrance in transition states. [Display omitted] ► An easy metal-free access to perfluoroalkylated 1,2,3-triazoles. ► 1,3-Dipolar cycloadditions of methyl 2-perfluoroalkynoates with various azides. ► Study on the scope and regiochemistry of the cycloaddition. ► Ratio of regioisomers was determined by FMO interaction and steric hindrance. 1,3-Dipolar cycloadditions of methyl 2-perfluoroalkynoates with various azides have been examined, leading to a simple metal-free synthetic protocol for the synthesis of perfluoroalkylated 1,2,3-triazoles. The regiochemical results demonstrated that the cycloaddition was controlled by FMO (the frontier molecular obitals) interaction and steric hindrance in transition states.