for the synthesis of 1,1-diarylethylenes using palladium catalysis has been developed. The new catalyticsystem based on Pd/Xphos–SO3Na or Pd/MeDavephos–CF3SO3 in PEG/H2O under microwave irradiation was found to be the best conditions for this transformation. The recyclability of the palladium catalyst system was also studied, and it was found to be active over nine runs without significant loss in its
已开发出一种绿色的Barluenga-Valdés交叉偶联反应,利用钯催化合成1,1-二芳基乙烯。发现在微波辐射下,基于PEG / H 2 O中Pd / Xphos-SO 3 Na或Pd / MeDavephos-CF 3 SO 3的新催化体系是该转化的最佳条件。还对钯催化剂体系的可回收性进行了研究,发现钯催化剂体系在九次运行中均具有活性,而活性没有明显损失。
Ag-Mediated Radical Cyclization of 2-Alkynylthio(seleno)anisoles: Direct Synthesis of 3-Phosphinoylbenzothio(seleno)phenes
A new method for the directsynthesis of 3-phosphinoylbenzothio(seleno)phenes has been achieved through an Ag-mediated radical addition–cyclization of 2-alkynylthio(seleno)anisoles with secondary phosphine oxides in good yields under mild conditions. In this single reaction, benzenethiophene or benzeneselenophene skeleton, C(sp2)–P and C(sp2)–S bonds can be constructed with the cleavage of the C(sp3)–S
aryl iodides in the presence of catalytic amounts of [Pd(phen)2][PF6]2 resulted in the efficient formation of 3-arylated benzo[b]thiophenes, and a range of aryl iodides with electron-donating or -withdrawing groups could be used. While this reaction proceeded in the presence of aromatic and aliphatic groups on the terminal alkynyl carbon atom, silyl and alkoxycarbonyl groups hampered the reaction. Furthermore
在催化量的[Pd(phen)2 ] [PF 6 ] 2存在下,邻-(1-炔基)硫代苯甲醚与芳基碘的芳基环化反应可有效形成3-芳基苯并[ b ]噻吩可以使用一定范围的带有给电子或吸电子基团的芳基碘化物。尽管该反应在末端炔基碳原子上存在芳族和脂族基团的情况下进行,但是甲硅烷基和烷氧基羰基基团阻碍了反应。此外,该方法可扩展到由N,N-二甲基-o合成3芳基吲哚-(1-炔基)苯胺。所有这些反应都通过裂解碳-杂原子键而顺利进行。除所需的环化产物外,在硫原子上使用邻-(羟丙基)苯基甲基取代基提供了异色满,其应通过羟基分子内攻击苄基碳原子而形成。
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。
p-Toluenesulfonic acid-promoted selective functionalization of unsymmetrical arylalkynes: a regioselective access to various arylketones and heterocycles
Regioselective hydration of a wide range of internalalkynes has been afforded in high to good yields by using PTSA in EtOH. The scope of the reaction of alkynes has been delineated. Arylaliphatic alkynes and diarylalkynes were regioselectively hydrated in good to excellent yields and short reaction times when the reaction was achieved under microwave irradiation. Moreover, diarylalkynes, arylenynes