Cover Picture

The cover picture shows the copper-catalyzed Ullmann-Ma reaction of aryl halides with nucleophiles by the assistance of two-generation ligands, amino acids and oxalic diamides or related amides. Ullmann-Ma reaction is one of the most important transformations for the construction of aryl carbon-carbon and carbon-heteroatom bonds in organic chemistry. For the details about the history, development, scope and applications of Ullmann-Ma reaction, please see the article by Cai et al. on page 879–893.