[Pd(NHC)(μ-Cl)Cl]2: Versatile and Highly Reactive Complexes for Cross-Coupling Reactions that Avoid Formation of Inactive Pd(I) Off-Cycle Products

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Catherine S.J. Cazin¹  Alan M.C. Obled²  Michal Szostak³  Fady Nahra⁴  Tongliang Zhou⁵  Siyue Ma⁵  Albert Poater⁶  Luigi Cavallo⁷  Steven P. Nolan⁸ 

[1] Corresponding author;Separation and Conversion Technology Unit, VITO (Flemish Institute for Technological Research), Boeretang 200, 2400 Mol, Belgium;Technology, KAUST Catalysis Center (KCC), 23955-6900 Thuwal, Saudi Arabia;Department of Chemistry and Center for Sustainable Chemistry, Ghent University, Krijgslaan 281, S-3, 9000 Ghent, Belgium;Department of Chemistry, Rutgers University, 73 Warren Street, Newark, NJ 07102, USA;EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK;Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, c/ Maria Aurèlia Capmany 69, Campus Montilivi, 17003 Girona, Catalonia, Spain;;King Abdullah University of Science &

关键词: Chemistry;    Inorganic Chemistry;    Catalysis;    Organic Synthesis;   

DOI  :  

来源: DOAJ

【 摘 要 】

Summary: The development of more reactive, general, easily accessible, and readily available Pd(II)–NHC precatalysts remains a key challenge in homogeneous catalysis. In this study, we establish air-stable NHC–Pd(II) chloro-dimers, [Pd(NHC)(μ-Cl)Cl]2, as the most reactive Pd(II)–NHC catalysts developed to date. Most crucially, compared with [Pd(NHC)(allyl)Cl] complexes, replacement of the allyl throw-away ligand with chloride allows for a more facile activation step, while effectively preventing the formation of off-cycle [Pd2(μ-allyl)(μ-Cl)(NHC)2] products. The utility is demonstrated via broad compatibility with amide cross-coupling, Suzuki cross-coupling, and the direct, late-stage functionalization of pharmaceuticals. Computational studies provide key insight into the NHC–Pd(II) chloro-dimer activation pathway. A facile synthesis of NHC–Pd(II) chloro-dimers in one-pot from NHC salts is reported. Considering the tremendous utility of Pd-catalyzed cross-coupling reactions and the overwhelming success of [Pd(NHC)(allyl)Cl] precatalysts, we believe that NHC–Pd(II) chloro-dimers, [Pd(NHC)(μ-Cl)Cl]2, should be considered as go-to precatalysts of choice in cross-coupling processes.

【 授权许可】

Unknown