Recent Progress on Chan-Lam Coupling Reactions Catalyzed by Copper(II) Complexes

Copper-catalyzed Chan-Lam reaction represents an important and highly efficient method for the synthesis of organic molecules containing carbon-heteroatom (C-N, C-O, C-S) bonds, which has many advantages such as mild conditions, wide substrates range and high yields. Therefore, the Chan-Lam coupling reactions are extensively applied in organic synthesis, medicinal chemistry and material science, etc. Although many catalytic systems using different copper salt alone or in combination with various ligands for Chan-Lam coupling reaction have been extensively reported by different groups, the studies on the Chan-Lam coupling reaction employing well-defined copper complexes as catalysts were underdeveloped. In recent years, the Chan-Lam reactions catalyzed by copper complexes with different ligands have attracted more special attention from synthetic chemist and made many achievements. Some novel copper complexes have been designed and synthesized, which were further used as efficient catalysts for Chan-Lam coupling reactions of arylboronic acids with various nucleophiles. The recent progresses on Chan-Lam coupling reactions catalyzed by well-defined copper (II) complexes are summarized from two aspects of homogeneous catalysis and heterogeneous catalysis in detail. Then the homogeneous Chan-Lam reactions are classified by the different coordination mode of copper complexes, and the heterogeneous Chan-Lam reactions are described according to chronological order. The reaction mechanism on Chan-Lam coupling proposed by different research groups is also straightened out and discussed. Finally, the development prospects of this research field are pointed out.