Synthesis and Evaluation of Photophysical Properties of C‐3 Halogenated Derivatives of <scp>2‐Phenylimidazo</scp>[1,2‐<i>a</i>]pyridine
Hong Chen, Yanyan Wang, Qingjie Liu, Yanchun Guo, Shuxia Cao, Yufen Zhao
Abstract
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.