Synthesis and Evaluation of Photophysical Properties of C-3 Halogenated Derivatives of 2-Phenylimidazo[1,2-a]pyridine

Comprehensive Summary A CuX-mediated regioselective halogenation reaction of 2-phenylimidazo[1,2-a]pyridine in the presence of oxygen is introduced in this paper. This reaction provides an effective method for the production of C-3 halogenated 2-phenylimidazo[1,2-a]pyridines with a yield of up to 96%. A plausible mechanism for the formation of title compounds via 2-phenylimidazo[1,2-a]pyridine-CuX complex intermediate is proposed. The structure of representative compounds is established by the single crystal XRD method. The electronic structure, corroborated by Hirshfeld surface analysis and DFT calculations, rationalizes characters of relevant absorptions and emission as well as large Stokes shifts.

Automated summary

This paper introduces a CuX-mediated regioselective halogenation reaction of 2-phenylimidazo[1,2-a]pyridine in the presence of oxygen. The reaction provides an effective method for the production of C-3 halogenated 2-phenylimidazo[1,2-a]pyridines with high yield. The proposed mechanism involves the formation of title compounds via a 2-phenylimidazo[1,2-a]pyridine-CuX complex intermediate. The structure of representative compounds is determined using the single crystal XRD method. The electronic structure analysis explains the absorption and emission characteristics as well as the large Stokes shifts.