Copper-catalyzed aromatic C–H bond halogenation with lithium halides under aerobic conditions
作者:Song Mo、Yamin Zhu、Zengming Shen
DOI:10.1039/c3ob40185e
日期:——
A concise and practical Cu-catalyzed protocol for the preparation of chloro- and bromoarenes via C–H bond activation has been developed. The advantages of this strategy are the employment of cheap Cu(NO3)2·3H2O, LiX and O2, and its compatibility with both electron-donating and electron-withdrawing substituents on aryl rings.
Palladium-Catalyzed Directed Halogenation of Bipyridine <i>N</i>-Oxides
作者:Sina P. Zucker、Friedrich Wossidlo、Manuela Weber、Dieter Lentz、C. Christoph Tzschucke
DOI:10.1021/acs.joc.7b00444
日期:2017.6.2
The palladium-catalyzed directed C–H halogenation of bipyridine N-oxides was investigated. Using NCS or NBS (N-chloro- or N-bromosuccinimide) and 5 mol % Pd(OAc)2 in chlorobenzene (0.10 molar) at 110 °C, pyridine-directed functionalization took place and 3-chloro- or 3-bromobipyridine N-oxides were obtained in high yields. The reaction is sensitive to steric hindrance by 4- and 6′-substituents. Only
Cu-Mediated Direct Aryl CH Halogenation: a Strategy to Control Mono- and Di-Selectivity
作者:Zhi-Jun Du、Lian-Xun Gao、Ying-Jie Lin、Fu-She Han
DOI:10.1002/cctc.201300734
日期:2014.1
A protocol for the copper‐mediated directarylCHhalogenation is presented. Highly selective mono‐ and di‐halogenations are achieved by using acyl hypohalites, generated in situ from the readily available carboxylic acid and N‐halosuccinimides (NXS; X=Br and Cl) as powerful halogenating reagents. The correct choice of carboxylic acid additives and solvents is essential for both high yield and selectivity
提出了铜介导的直接芳基CH卤化的方案。通过使用酰基次卤酸盐来实现高度选择性的单卤化和二卤化,酰基次卤酸盐是由现成的羧酸和N-卤代琥珀酰亚胺(NXS; X = Br和Cl)原位生成的,作为强力卤化试剂。正确选择羧酸添加剂和溶剂对于高收率和选择性都至关重要。因此,使用廉价的铜催化剂和从容易负担得起且易于处理的羧酸和NXS(X = Br和Cl)原位生成酰基次卤酸盐卤化试剂的新策略为实际应用提供了优势。
[Cp*RhCl<sub>2</sub>]<sub>2</sub>: mechanosynthesis and applications in C–H bond functionalisations under ball-milling conditions
作者:José G. Hernández、Carsten Bolm
DOI:10.1039/c5cc04423e
日期:——
Under LAG conditions, [Cp*RhCl2]2 was prepared by mechanochemical synthesis and applied in directed C–H bond funtionalisations.
imidazolium-containing mesoporous coordination polymer and organic polymer-based platforms were successfully exploited to develop single-site heterogenized Pd–NHC catalysts for oxidative arene/heteroarene C–H functionalization reactions. The catalysts were efficient in directed arene halogenation, and nondirected arene and heteroarene arylation reactions. High catalytic activity, excellent heterogeneity and