Pd/C as a Catalyst for Completely Regioselective CH Functionalization of Thiophenes under Mild Conditions
作者:Dan-Tam D. Tang、Karl D. Collins、Johannes B. Ernst、Frank Glorius
DOI:10.1002/anie.201309305
日期:2014.2.10
The completely C3‐selective arylation of thiophenes and benzo[b]thiophenes was achieved by using Pd/C as a heterogeneous catalyst without ligands or additives undermild reaction conditions. The practicability of this transformation is demonstrated by notable functional group tolerance and the insensitivity of the reaction to H2O and air. This method is also applicable to nitrogen‐ and oxygen‐containing
通过在温和的反应条件下使用Pd / C作为不带配体或添加剂的非均相催化剂,可以实现噻吩和苯并[ b ]噻吩的完全C3选择性芳基化。该转化的实用性通过显着的官能团耐受性和反应对H 2 O和空气的不敏感性得到证明。该方法也适用于含氮和氧的杂环,产生相应的C2芳基化产物。三相试验以及汞中毒和热过滤试验表明,催化活性物质在性质上是异质的。
Pd-Catalyzed β-Selective Direct C–H Bond Arylation of Thiophenes with Aryltrimethylsilanes
作者:Kenji Funaki、Tetsuo Sato、Shuichi Oi
DOI:10.1021/ol3029109
日期:2012.12.21
Direct arylation of thiophenes and benzothiophenes with aryltrimethylsilanes was effectively catalyzed by PdCl2(MeCN)2 in the presence of CuCl2 as an oxidant. The reaction preferentially occurred at the β-position of both thiophenes and benzothiophenes.
Uncatalyzed side-chain halogenations of polymethyl-substituted thiophenes take place cleanly and regioselectively at the α-position. Thus, for example, treatment of tetramethylthiophene with 1 equiv of bromine in CCl4 at −18 °C affords 2-bromomethyl-3,4,5-trimethylthiophene in 76% isolated yield, while the use of 2 equiv of bromine produces 2,5-bis(bromomethyl)-3,4-dimethylthiophene nearly quantitatively
General synthesis of 2,5-dihydrothiophenes (3-thiolenes) from diketo sulfides
作者:Juzo Nakayama、Haruki Machida、Masamatsu Hoshino
DOI:10.1016/s0040-4039(00)98357-6
日期:1985.1
The intramolecular reductive coupling reaction of easily accessible diketo sulfides by a low-valenttitaniumreagent [prepared fromtitanium(IV) chloride and zinc powder] provides an efficient general synthesis of 2,5-dihydrothiophenes.
Preparation of 1-phenylthio-1,3-dienes by reaction of 2,5-dihydrothiophenes with benzyne through fragmentation of sulfonium ylide intermediates
作者:Juzo Nakayama、Yuichi Kumano、Masamatsu Hoshino
DOI:10.1016/s0040-4039(01)80633-x
日期:1989.1
reaction of a series of 2,5-dihydrothiophenes with benzyne, generated from 2-carboxybenzenediazonium chloride, affords 1-phenylthio-1,3-dienes in good yields through the fragmentation of sulfoniumylideintermediates.