Transition-Metal-Free C-H/C-Li Coupling of Nonaromatic 2 H -Imidazole 1-Oxides with Pentafluorophenyl Lithium in the Design of Novel Fluorophores with Intramolecular Charge Transfer Effect.

Methodology of nucleophilic substitution of hydrogen (S _N ^H ) was first applied for the direct modification of nonaromatic 2 H -imidazoles to afford novel polyfluoroarylated azaheterocycles. Scope, tolerance for these transition-metal-free C-H/C-Li coupling reactions, and photophysical properties for the novel 4-(perfluorophenyl)-5-aryl-2 H -imidazoles were comprehensively studied. In particular, some of the obtained perfluoroaryl-substituted 2 H -imidazoles were found to be of particular interest as promising push-pull fluorophore systems in the design of fluorometric sensor materials due to the effect of intramolecular charge transfer.