Construction of fluorescence-tunable pyrido-fused benzimidazoles via direct intramolecular C–H amination under transition-metal-free conditions

Abstract

A novel methodology was discovered to construct multi-phenyl substituted pyrido-fused benzimidazole (PBI) core frameworks via direct oxidative intramolecular C–H amination of α-unsubstituted pyridinium salts under transition-metal free conditions. The resulting highly π-conjugated PBI derivatives exhibited highly tunable fluorescent emission not only in solution but also in the solid state.