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

Abstract

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. Keywords copper(II) complex; arylboronic acid; nucleophile; Chan-Lam coupling; N-arylation Chan-Lam 偶联反应, 也叫 Chan-Evans-Lam 偶联, 是指铜盐催化(或促进)下芳基硼酸(或锡烷、硅氧烷)与 含 N-H、 O-H 或 S-H 的化合物进行氧化偶联形成芳 基碳-杂原子键的反应(Scheme 1). 该反应是在 1998 年 由 Chan [1] 、Evans [2] 和 Lam [3] 等同时发现并独立报道的. 相比钯催化 N-芳基化或 O-芳基化的 Buchwald-Hartwig 偶联反应, Chan-Lam 反应使用廉价易得的铜盐作为催 化剂, 在室温和敞开体系中进行, 具有条件温和、底物

Copper Complexes with N,N,N-Tridentate Quinolinyl Anilido-Imine Ligands: Synthesis and Their Catalytic Application in Chan−Lam Reactions

“…Cu(II) complex 1 was prepared using the literature method [26]. The other Cu complexes (2)(3)(4)(5) were synthesized following the analogous methods. The reactions of ligands L2H-L5H with n-BuLi at −78 • C followed by adding CuCl 2 afforded complexes 2-5 as brown powders in 55-68% yields, respectively (Scheme 2).…”

“…The construction of C-N bonds is one of the most widely practiced reactions in synthetic chemistry. The name reactions, such as the Buchwald-Hartwig [1,2], Chan-Lam [3,4] and Ullmann [5] reactions, have been extensively explored for C-N bond formation. These reactions have a wide range of applications, such as in pesticide synthesis and pharmaceutical and material chemistry [6].…”