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烷基芳基醚广泛存在于天然产物和药物分子中。钯和铜催化构筑C—O键的方法已成为合成烷基芳基醚的有效策略。本文总结了钯和铜催化的脂肪醇芳基化反应的最新研究进展。以Buchwald小组发展的基于联苯骨架的二叔丁基取代单膦配体,Hartwig小组发展的基于五苯基取代的二茂铁骨架的二叔丁基取代单膦配体或Beller小组发展的基于二吡唑骨架的二金刚烷基取代的单膦配体,可高效实现钯催化的各类脂肪醇和芳基卤代烃的C—O偶联。在铜催化反应条件下,1,10-菲罗啉及其衍生物和β-二羰基化合物是反应活性最高的两类配体。总的来说,和铜催化条件相比,钯催化的C—O偶联反应具有反应条件温和,官能团兼容性好,底物普适性广等优点。此外,对两类催化体系在配体选用、反应活性、β-H消除反应和反应机理等方面的差异进行了探讨。设计与合成新型配体被认为是C—O偶联反应取得进一步发展的关键。
Alkyl aryl ethers are widely found in natural products and drug molecules. Palladium and copper catalysts for building C-O bonds have become an effective strategy for the synthesis of alkyl aryl ethers. This review summarizes recent progress in the palladium and copper catalyzed arylation of fatty alcohols. The di-tert-butyl-substituted monophosphine ligand based on the biphenyl backbone developed by the Buchwald group, the di-tert-butyl substituted monophosphine ligand based on the pentaphenyl-substituted ferrocene backbone or the Beller group developed by the Hartwig group are based on Bis-adamantyl-substituted monophosphine ligands of the dipyrazole skeleton can efficiently achieve the C-O coupling of palladium-catalyzed aliphatic alcohols with aryl halocarbons. Under copper catalytic conditions, 1,10-phenanthroline and its derivatives and β-dicarbonyl compounds are the two most reactive ligands. In general, palladium-catalyzed C-O coupling reactions have the advantages of mild reaction conditions, good functional group compatibility, and broad substrate versatility compared to copper catalysis. In addition, the differences of ligands selection, reactivity, β-H elimination reaction and reaction mechanism were discussed. Design and synthesis of new ligands are considered as the key to the further development of C-O coupling reaction.