Catalytic Access to Indole-Fused Benzosiloles by 2-Fold Electrophilic C–H Silylation with Dihydrosilanes
摘要:
A protocol for the catalytic synthesis of indole-fused benzosiloles starting from 2-aryl-substituted indoles and dihydrosilanes is reported. Compared to known procedures, this method does not require prefunctionalized, starting materials and, hence, allows for a rapid access to those siloles. The net reaction is a 2-fold electrophilic C-H silylation catalyzed by cationic Ru-S complexes. Both reaction steps were separately investigated, and these results eventually led to the development of a two-step procedure. By preparing new Ru-S complexes with different weakly coordinating anions (WCAs), it is also shown that the latter can have a dramatic influence on the outcome of these reactions. Furthermore, the substrate scope of the new method is discussed.
Rh(III)-Catalyzed C–C/C–N Coupling of Imidates with α-Diazo Imidamide: Synthesis of Isoquinoline-Fused Indoles
作者:He Wang、Lei Li、Songjie Yu、Yunyun Li、Xingwei Li
DOI:10.1021/acs.orglett.6b01284
日期:2016.6.17
Imidate esters and diazo compounds have been established as bifunctional substrates for the construction of biologically active fused heterocycles viarhodium-catalyzed C–H activation and C–C/C–N coupling. This reaction occurs undermildconditions with high efficiency, step economy, and low catalyst loading.
A simple and selective protocol for the halogenation of indoles with copper(II) bromide or chloride to synthesize 2-halo-, 3- halo-, and 2,3-dibromoindoles was developed. It was found that both base and water could be used as switches for the selectivity of the halogenation reactions. In the presence of copper(II) halide and sodium hydroxide, 3-haloindoles were obtained as the major prod- ucts, whereas
开发了一种用溴化铜 (II) 或氯化铜卤化吲哚以合成 2-卤代、3-卤代和 2,3-二溴吲哚的简单且选择性的方案。发现碱和水都可以用作卤化反应选择性的开关。在卤化铜 (II) 和氢氧化钠存在的情况下,主要产物是 3-卤代吲哚,而当加入水而不是氢氧化钠时,选择性转向 2,3-二卤代吲哚。此外,在标准条件下,3-取代吲哚的 2-卤化也以中等至良好的产率成功进行。
Cooperative Catalytic Activation of Si−H Bonds by a Polar Ru−S Bond: Regioselective Low-Temperature C−H Silylation of Indoles under Neutral Conditions by a Friedel−Crafts Mechanism
作者:Hendrik F. T. Klare、Martin Oestreich、Jun-ichi Ito、Hisao Nishiyama、Yasuhiro Ohki、Kazuyuki Tatsumi
DOI:10.1021/ja111483r
日期:2011.3.16
Merging cooperative Si-H bond activation and electrophilicaromaticsubstitution paves the way for C-3-selective indole C-H functionalization under electronic and not conventional steric control. The Si-H bond is heterolytically split by the Ru-S bond of a coordinatively unsaturated cationic ruthenium(II) complex, forming a sulfur-stabilized silicon electrophile. The Wheland intermediate of the subsequent
Synthesis and Preliminary Biological Studies of 3-Substituted Indoles Accessed by a Palladium-Catalyzed Enantioselective Alkene Difunctionalization Reaction
作者:Tejas P. Pathak、Keith M. Gligorich、Bryan E. Welm、Matthew S. Sigman
DOI:10.1021/ja103472a
日期:2010.6.16
A unique alkene difunctionalization reaction that allows rapid construction of molecular complexity around the biologically relevant indole framework has been developed. The reaction proceeds with up to 87% yield, 99:1 er, and >20:1 dr. Evaluation of several of the compounds revealed promising anticancer activity against MCF-7 cells.
已经开发出一种独特的烯烃双官能化反应,可以在生物相关的吲哚框架周围快速构建分子复杂性。反应以高达 87% 的产率、99:1 er 和 >20:1 dr 进行。对几种化合物的评估揭示了对 MCF-7 细胞的有希望的抗癌活性。
A Straightforward Approach to Tetrahydroindolo[3,2-<i>b</i>]carbazoles and 1-Indolyltetrahydrocarbazoles through [3+3] Cyclodimerization of Indole-Derived Cyclopropanes
作者:Olga A. Ivanova、Ekaterina M. Budynina、Victor N. Khrustalev、Dmitriy A. Skvortsov、Igor V. Trushkov、Mikhail Ya. Melnikov
DOI:10.1002/chem.201502287
日期:2016.1.22
A rapid new approach to produce biologically relevant bisindoles, namely indolyltetrahydrocarbazoles and indolo[3,2‐b]carbazoles, has been developed, based on the Ga(OTf)3‐catalyzed [3+3] cyclodimerization of indole‐derived donor–acceptor cyclopropanes. Chemoselectivity of the process depends on the location of the three‐membered ring at the indole core.
基于由吲哚衍生的供体-受体的Ga(OTf)3催化的[3 + 3]环二聚作用,已开发出一种快速的新方法来生产生物学相关的双吲哚,即吲哚基四氢咔唑和吲哚[3,2- b ]咔唑。环丙烷。该过程的化学选择性取决于三元环在吲哚核上的位置。