Metal-Reductant-Free Electrochemical Nickel-Catalyzed Couplings of Aryl and Alkyl Bromides in Acetonitrile
作者:Robert J. Perkins、Alexander J. Hughes、Daniel J. Weix、Eric C. Hansen
DOI:10.1021/acs.oprd.9b00232
日期:2019.8.16
attractive approach for the synthesis of complex molecules at both small and large scale, two barriers for large-scale applications have remained: the use of stoichiometric metalreductants and a need for amide solvents. In this communication, new conditions that address these challenges are reported. The nickel-catalyzed reductive cross-coupling of aryl bromides with alkyl bromides can be conducted in a
A robust and sustainable C(sp2)–C(sp3) cross-electrophile coupling was developed via nickel/copper synergistic catalysis under micellar conditions.
通过镍/铜协同催化在胶束条件下开发了稳健且可持续的C(sp²)–C(sp³)交叉电愿偶联。
General C(sp<sup>2</sup>)–C(sp<sup>3</sup>) Cross-Electrophile Coupling Reactions Enabled by Overcharge Protection of Homogeneous Electrocatalysts
作者:Blaise L. Truesdell、Taylor B. Hamby、Christo S. Sevov
DOI:10.1021/jacs.0c01475
日期:2020.3.25
development of an electrochemical methodology for XEC that utilizes redox-active shuttles developed by the energy-storage community to protect reactive coupling catalysts from overreduction. The resulting electrocatalytic system is practical, scalable, and broadly applicable to the reductive coupling of a wide range of aryl, heteroaryl, or vinylbromides with primary or secondary alkyl bromides. The impact
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
A Practical Method for Continuous Production of sp3‐Rich Compounds from (Hetero)Aryl Halides and Redox‐Active Esters
作者:Eiichi Watanabe、Yiding Chen、Oliver May、Steven V. Ley
DOI:10.1002/chem.201905048
日期:2020.1.2
practically useful coupling reaction between aromatic halides and redox-active esters was realized by nickel catalysis through the use of a packed zinc bed column in continuous flow. Multiple reuse of the column showed a negligible decrease in efficiency, affording high space/time yields. A wide range of substrates, including a number of heteroaryl halides and polyfunctional materials were coupled in generally