Elucidating ligand effects in rhodium(Ⅲ)-catalyzed arene-alkene coupling reactions  

作　　者：Kongchuan Wu Dandan Lu Jianbin Lin Ting-Bin Wen Wei Hao Kai Tan Hui-Jun Zhang 

机构地区：[1]Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China [2]Beijing National Laboratory for Molecular Sciences,CAS Key Laboratory of Molecular Recognition and Function,Institute of Chemistry,Chinese Academy of Sciences(CAS),Beijing 100190,China

出　　处：《Chinese Chemical Letters》2024年第5期130-134,共5页中国化学快报（英文版）

基　　金：financial support from the National Natural Science Foundation of China(Nos.21772162,21772165,22171237,22071208);Youth Innovation foundation of Xiamen(No.3502Z20206058).

摘　　要：Rhodium(Ⅲ)-catalyzed C-H couplings of arenes with alkenes are among the most powerful methods for C-C bond formation.For these transformations,subtle manipulation of ancillary ligands can lead to dramatic changes in reactivity and selectivity.However,detailed mechanistic studies concerning the ligand effects are rare.In this study,we investigated the origin of ligand-controlled product-selectivity in rhodium(Ⅲ)-catalyzed C-H couplings of arenes with alkenes,using a series of well-defined[CpXRhⅢ]complexes that feature electronically or sterically distinct Cp^(X)(Cp(η^(5)-C_(5)H_(5)),Cp^(CF3)(η^(5)-C_(5)Me_(4)CF_(3))and Cp^(∗)(η^(5)-C_(5)Me_(5)))ligands.A combination of experimental and theoretical investigations showed that(i)rhodium hydride species containing the electron rich Cp^(∗)ligand can undergo reinsertion of the alkene,thereby allowing rhodium-walking,(ii)rhodium hydride species involving the electron-deficient Cp or Cp^(CF3) ligands prefer reductive elimination rather than alkene insertion.These findings offer valuable insights on future rational catalyst design for selective arene-alkene cross coupling reactions.

关 键 词：ORGANOMETALLICS Transition metal catalysis Arene-alkene coupling β-H elimination Rhodium hydride 

分 类 号：O621.251[理学—有机化学]