Over the past decade, the copper-catalyzed modified Ullmann reaction has emerged as a powerful approach by means of additive copper chelating agents.(9) Moreover, it could be extended to other nitrogen-containing reagents such as anilines, amides, and carbamates.(10) Progress has been obtained through the use of various copper-chelating agents (α-aminoacids, β-aminoacids, phenolic derivatives, or ethylenediamine derivatives), which dramatically ...
