Copper-Mediated Chelation-Assisted <i>Ortho</i> Nitration of (Hetero)arenes
作者:Lin Zhang、Zhenhua Liu、Huiqin Li、Guichun Fang、Badru-Deen Barry、Tuemay Abadi Belay、Xihe Bi、Qun Liu
DOI:10.1021/ol2028288
日期:2011.12.16
A novel copper-mediated chelation-assisted ortho C–H nitration of (hetero)arenes has been developed for the first time, which used dioxygen as terminal oxidant and 1,2,3-TCP as solvent, leading to the synthesis of nitroaromatics with excellent regioselectivity and in good yields. Mechanistic investigations indicate a mechanism involving a four-centered transition state, with simultaneous cleavage of
Pd-Catalyzed Homo Cross-Dehydrogenative Coupling of 2-Arylpyridines by Using I2 as the Sole Oxidant
作者:Chao-Jun Li、Wenbo Liu、Youquan Zhu
DOI:10.1055/s-0035-1561399
日期:——
rationalize this homo CDC reaction. A palladium-catalyzed homo cross-dehydrogenative coupling (CDC) of 2-arylpyridines via C–Hactivation is described. This reaction employs I2 as the sole oxidant without any other additives, which complements the hypervalent iodine chemistry, such as of phenyliodonium diacetate (PIDA) or IOAc, in C–Hactivation research field. A tentative mechanism involving a Pd(II)–Pd(IV)
One-pot direct C–H arylation of arenes in water catalysed by RuCl3·nH2O–NaOAc in the presence of Zn
作者:Luis A. Adrio、José Gimeno、Cristian Vicent
DOI:10.1039/c3cc43452d
日期:——
The inexpensive and commercially available catalytic system RuCl3·nH2OâNaOAcâZn is active in water for the direct CâH arylation of arenes with aryl/heteroaryl chlorides. The reaction can be accelerated by the use of microwave irradiation and can also be scaled up to a multi-gram scale with excellent isolated yields.
Combination of RuCl<sub>3</sub>·xH<sub>2</sub>O with PEG – a simple and recyclable catalytic system for direct arylation of heteroarenes via C–H bond activation
作者:Lei Jian、Hai-Yu He、Jin Huang、Qian-Hui Wu、Mao-Lin Yuan、Hai-Yan Fu、Xue-Li Zheng、Hua Chen、Rui-Xiang Li
DOI:10.1039/c7ra02638b
日期:——
A simple and recyclable catalytic system for directarylation of heteroarenes via C–H bond activation was developed with a relatively inexpensive RuCl3·xH2O as a catalyst and PEG-400 as a green medium without any additive or ligand. This system not only showed excellent functional group compatibility, but also the ratio of mono- to diarylated product was easily regulated by varying the reaction conditions
通过使用相对便宜的RuCl 3 · x H 2 O作为催化剂和PEG-400作为绿色介质,没有任何添加剂或配体,开发了一种简单且可回收的催化系统,用于通过C–H键活化杂芳烃直接芳基化。该体系不仅显示出优异的官能团相容性,而且通过改变反应条件也很容易调节单芳基化产物与二芳基化产物的比例。而且,该转化可以在空气中进行,并且在0.3mol%的低催化剂负载下可以容易地按比例放大至克级。特别地,在将该催化剂循环六次之后,获得了85%的良好产率。