N-arylation and O-arylation of aryl halides by Ullmann-type cross coupling reaction under mild reaction conditions in a short reaction time. Two phosphine sulphide ligands and their corresponding Pd(0) complexes namely [Pd(p2S2)(dba)] and [Pd(pp3S4)(dba)], were synthesized, where p2S2 is 1,2-bis(diphenylphosphino)ethane disulfide, pp3S4 is tris[2-(diphenylphosphino)ethyl]phosphine tetrasulfide and dba
本文描述了在温和的反应条件下,在较短的反应时间内,钯(0)催化Ullmann型交叉偶联反应进行芳基卤化物的N-芳基化和O-芳基化的有效方法。合成了两个硫化膦配体及其相应的Pd(0)络合物,即[Pd(p 2 S 2)(dba)]和[Pd(pp 3 S 4)(dba)],其中p 2 S 2为1, 2-双(二苯基膦基)乙烷二硫化物,pp 3 S 4是三[2-(二苯基膦基)乙基]膦四硫化物,dba是二亚苄基丙酮。通过改变温度,溶剂,碱和催化剂的负载量,确定了使用碘代苯和苯并咪唑进行芳基化反应的最佳反应条件。使用碘代苯/溴苯和具有不同空间和电子性质的各种取代的芳基胺/苯酚/醇进行交叉偶联反应,从而以良好或优异的收率得到所需的N-芳基胺/二芳基醚/烷基芳基醚( 70–94%)。
A New, Efficient and Recyclable Lanthanum(III) Oxide- Catalyzed CN Cross-Coupling
作者:S. Narayana Murthy、B. Madhav、V. Prakash Reddy、Y. V. D. Nageswar
DOI:10.1002/adsc.200900691
日期:2010.12.17
A new and efficient protocol for the CN cross-coupling of aryl halides with heteroaromatic amines in the presence of lanthanum(III) oxide (10 mol%) as a recyclable catalyst, N,N′-dimethylethylenediamine (DMEDA) (20 mol%) and potassium hydroxide (KOH) as a base in dimethyl sulfoxide (DMSO) at 110 °C has been developed. This inexpensive catalytic system is highly effective towards the amination of aryl
Iron-Catalyzed One-Pot Synthesis of 2-Aminobenzothiazoles from 2-Aminobenzenethiols and Isothiocyanates under Ligand-Free Conditions in Water
作者:Qiuping Ding、Yiyuan Peng、Wenying Wang、Wenying Zhong、Runxia Zhou、Jinsheng Yu、Juan Dai
DOI:10.3987/com-10-12051
日期:——
A practical and efficient method for the synthesis of 2-aminobenzothiazoles has been developed via an iron-catalyzed one-pot tandemreaction. Various 2-aminobenzothiazoles were conveniently synthesized in moderate to excellent yields. It is highlighted that the reaction is conducted under ligand-free conditions in water.
Iron-Catalyzed Tandem Reactions of <i>ortho</i>-Aminobenzenethiols with Isothiocyanates Leading to 2-Aminobenzoazoles Under Ligand- and Solvent-Free Conditions
Abstract An efficient route to synthesize a variety of 2-aminobenzoazoles has been discovered. It involves the reaction of ortho-aminobenzenethiols with isothiocyanates via iron-catalyzed tandem addition-annulations process under ligand and solvent free conditions on silica gel surface. GRAPHICAL ABSTRACT
which prevails in versatile natural products and biologically active compounds. Herein, a switchable and scalable C–N coupling protocol was developed for the synthesis of these compounds from 2-chlorobenzothiazoles and primary amines. Gratifyingly, this protocol was achieved under transition-metal-free and solvent-freeconditions. Moreover, introducing an appropriate amount of NaH completely switched
2-氨基苯并噻唑包含一个有价值的结构基序,它普遍存在于多功能天然产物和生物活性化合物中。在此,开发了一种可切换和可扩展的 C-N 偶联方案,用于从 2-氯苯并噻唑和伯胺合成这些化合物。令人欣慰的是,该协议是在无过渡金属和无溶剂条件下实现的。此外,引入适量的 NaH 将选择性从单杂芳基化完全转变为二杂芳基化,进一步的研究为这一新发现提供了基本原理。此外,代表性产物3a和4a 的克级合成通过应用操作简单且无需手套箱的程序来实现,这揭示了这项工作的实际实用性。最后,量化绿色指标的评估提供了证据,证明我们的协议在绿色化学和可持续性方面优于文献。