Palladium-Catalyzed C–S Coupling: Access to Thioethers, Benzo[<i>b</i>]thiophenes, and Thieno[3,2-<i>b</i>]thiophenes
作者:Marius Kuhn、Florian C. Falk、Jan Paradies
DOI:10.1021/ol2016093
日期:2011.8.5
formation/cross-coupling/cyclization domino reaction using thiourea as a cheap and easy to handle dihydrosulfide surrogate has been developed. Structurally important biarylthioether, benzo[b]thiophenes, and thieno[3,2-b]thiophene scaffolds are provided in high yield.
已经开发出了第一个使用硫脲作为便宜且易于处理的二氢硫代用品的C-S键形成/交叉偶联/环化多米诺反应。以高收率提供结构上重要的联芳基硫醚,苯并[ b ]噻吩和噻吩并[3,2- b ]噻吩支架。
Synthesis of 2-substituted benzo[<i>b</i>]thiophenes <i>via</i> gold(<scp>i</scp>)–NHC-catalyzed cyclization of 2-alkynyl thioanisoles
作者:Christopher C. Dillon、Bagieng Keophimphone、Melissa Sanchez、Parveen Kaur、Hubert Muchalski
DOI:10.1039/c8ob02196a
日期:——
developed for the construction of a benzo[b]thiophene core via cyclization reaction of alkynes. Although few catalytic reactions were disclosed, most methods rely on stoichiometric activation of alkynes. Here we report an efficient method for the synthesis of 2-substituted benzo[b]thiophenes from 2-alkynyl thioanisoles catalyzed by a gold(I)–IPr hydroxide that is applicable to a wide range of substrates
苯并[ b ]噻吩杂环是许多重要的小分子药物和候选药物以及有机半导体材料的重要组成部分。已经开发了许多通过炔烃的环化反应来构建苯并[ b ]噻吩核的方法。尽管公开的催化反应很少,但是大多数方法依赖于炔烃的化学计量活化。在这里我们报告了一种由金催化的由2-炔基硫代苯甲醚合成2-取代的苯并[ b ]噻吩的有效方法(I)– IPr氢氧化物,适用于具有多种电子和空间特性的多种底物。另外,我们通过实验证明了酸添加剂及其共轭碱对催化剂周转至关重要。
A New Zn/TiCl<sub>4</sub>/LiAlH<sub>4</sub> Mediated Approach to 2-Aryl- or 2-Alkyl-Substituted Benzothiophenes via Intramolecular Cyclization
Methyl 2-(substituted benzoylthio)benzoates undergo intramolecular ring cyclizations in the presence of Zn/TiCl 4 /LiAlH 4 to give the corresponding 2-aryl- or alkylsubstituted benzo-thiophenes in good yields.
Nickel species have been introduced into porous phenanthroline-based organic polymer, which is catalytically active, regioselective, and recyclable for C−H activation of heterocycles. This work offers a new opportunity for design of novel non-noble metal-based heterogeneous catalysts for the regioselective C−H activation of heterocycles.
first example of near-room-temperature α-arylation of benzo[b]thiophenes is reported. The discovery rests on the observation of a switch in α-/β-regioselectivity at different loadings of Pd2(dba)3·CHCl3 in the coupling between benzo[b]thiophene and 4-iodotoluene. We show that this unprecedented regioselectivity switch is driven by a Ag(I)-mediated C–H activation at the α-C–H position, which becomes the