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%)。
Metal- and ligand-free Ullmann-type C–O and C–N coupling reactions promoted by potassium tert-butoxide
A simple, metal- and ligand-free procedure for the Ullmann-type C–O coupling reactions has been achieved by allowing aryl bromides to react with a variety of phenols in the presence of t-BuOK. Moderate to excellent yields of O-arylation products are obtained under mild conditions in a short time. In addition, two examples of C–N coupling reactions are also reported. A benzyne mechanism is proposed
An efficient protocol using copper based reagents for the coupling of aryl halides with phenols to generate diaryl ethers is described. A copper(I) complex, [Cu(CH3CN)4]ClO4, or the readily available copper(II) source, CuCO3·Cu(OH)2·H2O (in combination with potassium phosphate), can be used. Aryl halides and phenols with different steric and electronic demands have been used to assess the efficiency of the procedure. The latter source of copper gives better yields under all conditions.
Studies on nucleophilic substitution reactions with cyclopentadienyliron complexes of some chloroarenes and nitroarenes and syntheses of substituted arenes by demetallation of the substitution products
SNAr products, without significant steric hindrance. However, no reaction was observed in the treatment of XIVa or XIVb with DBM, suggesting that only with a bulky nucleophile such as that derived from DBM were steric hindrance effects sufficiently large to prevent an SNAr reaction with XIV, a or XIVb. Pyrolytic sublimation of the various SNAr products was found to cause decomposition in some cases
与环戊二烯基(CpFe的量)配合物的亲核取代反应米或- p被发现与来自乙酰乙酸乙酯(EAA)衍生的碳阴离子亲核体,二苯甲酰甲烷(DBM)或diacetylmethane(DAM) -二氯苯,得到单取代仅如先前对于CpFe的量观察到复杂的的Ø二氯苯。2,6-二甲基氯苯(XIVa)或2,6-二甲基硝基苯(XIVb)的CpFe络合物与衍生自氨,二甲胺,正丁胺,吡咯烷,乙醇,苯酚,邻硫代甲酚和EAA的亲核试剂的反应均得到S N氩气产物,无明显的空间位阻。然而,没有反应在XIVA或XIVb的与DBM的治疗中观察到,这表明仅与一个亲核试剂笨重例如从DBM衍生为空间位阻的影响足够大以防止一个S Ñ与XIV,一个或XIVb的氩反应。在某些情况下,发现各种S N Ar产品的热升华会引起分解,但在大多数情况下,会发生脱金属,从而生成取代的芳烃。在本工作中以这种方式制备的新取代的芳烃包括RC 6 H 4 CH(COC
Picolinamides as Effective Ligands for Copper-Catalysed Aryl Ether Formation: Structure-Activity Relationships, Substrate Scope and Mechanistic Investigations
作者:Carlo Sambiagio、Rachel H. Munday、Stephen P. Marsden、A. John Blacker、Patrick C. McGowan
DOI:10.1002/chem.201404275
日期:2014.12.22
picolinic acid amide derivatives as an effective family of bidentate ligands for copper‐catalysed arylether synthesis is reported. A fluorine‐substituted ligand gave good results in the synthesis of a wide range of arylethers. Even bulky phenols, known to be very challenging substrates, were shown to react with aryl iodides with excellent yields using these ligands. At the end of the reaction, the first