Verdazyl Radical Building Blocks: Synthesis, Structure, and Sonogashira Cross‐Coupling Reactions.

A general and effective method for the synthesis of 3‐phenylveradzyl radicals bearing a variety of iodophenyl substituents has been developed. The synthesized radicals have been characterized by ESR, UV/Vis spectroscopy, and cyclic voltammetry. Structures of biphenyl‐substituted radicals have been solved by X‐ray crystal structure analysis. The synthesized iodoverdazyls are applicable in the Sonogashira coupling reaction for the preparation of a wide range of ethynyl derivatives. Both N‐2 and C‐6 substituents were functionalized through Sonogashira coupling. [ABSTRACT FROM AUTHOR]