Dilithium Amides as a Modular Bis-Anionic Ligand Platform for Iron-Catalyzed Cross-Coupling
作者:Peter G. N. Neate、Bufan Zhang、Jessica Conforti、William W. Brennessel、Michael L. Neidig
DOI:10.1021/acs.orglett.1c02053
日期:2021.8.6
Dilithium amides have been developed as a bespoke and general ligand for iron-catalyzed Kumada–Tamao–Corriu cross-coupling reactions, their design taking inspiration from previous mechanistic and structural studies. They allow for the cross-coupling of alkyl Grignard reagents with sp2-hybridized electrophiles as well as aryl Grignard reagents with sp3-hybridized electrophiles. This represents a rare
Pd-Catalyzed reductive heck reaction of olefins with aryl bromides for Csp<sup>2</sup>–Csp<sup>3</sup> bond formation
作者:Liqun Jin、Jiaxia Qian、Nan Sun、Baoxiang Hu、Zhenlu Shen、Xinquan Hu
DOI:10.1039/c8cc02571a
日期:——
We developed a Pd-catalyzed intermolecular reductive Heck reaction to construct Csp2–Csp3 bonds between arylbromides and olefins. Various styrene derivatives, acyclic and cyclic alkenes, were well tolerated to couple with varied arylbromides in linear selectivity. Kinetic and deuterium labeling experiments suggested that i-PrOH provides a hydride through β-H elimination.
Mild Negishi Cross-Coupling Reactions Catalyzed by Acenaphthoimidazolylidene Palladium Complexes at Low Catalyst Loadings
作者:Zelong Liu、Ningning Dong、Mizhi Xu、Zheming Sun、Tao Tu
DOI:10.1021/jo400803s
日期:2013.8.2
3a exhibited extremely high catalytic activity toward Negishicross-coupling of alkylzinc reagents with a wide range of (hetero)arylhalides under mild reaction conditions within 30 min. Besides a great number of bromoarenes, various less expensive and inactive (hetero)aryl chlorides were coupled successfully with the alkyl- and arylzincreagents, in which active functional groups (such as -NH2) were
考虑到衍生自π-延伸的咪唑鎓盐的亚烷基的强大的σ-供体性质有利于提高所得钯N-杂环卡宾配合物的催化活性,因此制备了具有健壮的并咪唑-亚烷基钯配合物3a - c,具有不同的大取代基团通过在纯净的3-氯吡啶中与PdCl 2和K 2 CO 3加热,从相应的啶咪唑氯化物中得到满意的收率。即使在催化剂负载量低至0.25 mol%的情况下,配合物3a在温和的反应条件下,在30分钟内显示出对烷基锌试剂与各种(杂)芳基卤化物的Negishi交叉偶联极高的催化活性。除了大量的溴代芳烃外,还成功地将各种较便宜且不活泼的(杂)芳基氯化物与烷基-和芳基锌试剂偶联,其中具有活性官能团(例如-NH 2))即使在无保护的一锅双偶转换中也具有良好的耐受性。此外,在与仲烷基锌试剂偶联的情况下,有效抑制了导致异构化的线性产物的不希望的β-氢化物消除。通过杂芳基锌试剂和杂环氯代芳烃的偶联,该催化剂体系还显示出在杂二芳基结构方面
Efficient cross-coupling of aryl Grignard reagents with alkyl halides by recyclable ionic iron(iii) complexes bearing a bis(phenol)-functionalized benzimidazolium cation
designed and used to prepare ionic iron(III) complexes of the type [H3L][FeX4] (X = Cl, 2; X = Br, 3). Both 2 and 3 were characterized by elemental analysis, Raman spectroscopy, electrospray ionization mass spectrometry and X-ray crystallography. The catalytic performances of 2 and 3 in cross-coupling reactions using arylGrignardreagents with primary and secondary alkyl halides bearing β-hydrogens were
Iron Phosphine Catalyzed Cross-Coupling of Tetraorganoborates and Related Group 13 Nucleophiles with Alkyl Halides
作者:Robin B. Bedford、Peter B. Brenner、Emma Carter、Jamie Clifton、Paul M. Cogswell、Nicholas J. Gower、Mairi F. Haddow、Jeremy N. Harvey、Jeffrey A. Kehl、Damien M. Murphy、Emily C. Neeve、Michael L. Neidig、Joshua Nunn、Benjamin E. R. Snyder、Joseph Taylor
DOI:10.1021/om500518r
日期:2014.10.27
Iron phosphinecomplexes prove to be good precatalysts for the cross-coupling of alkyl, benzyl, and allyl halides with not only aryl triorganoborate salts but also related aluminum-, gallium-, indium-, and thallium-based nucleophiles. Mechanistic studies revealed that while Fe(I) can be accessed on catalytically relevant time scales, lower average oxidation states are not formed fast enough to be relevant