两亲性芳香亚胺环钯化合物及其Langmuir-Blodgett膜的制备、表征及催化活性

合成并表征了一系列新型两亲性芳香亚胺环钯化合物.结果显示,该系列环钯催化剂可高效催化均相条件下的Heck和Suzuki偶联反应.将两亲性芳香亚胺环钯二聚体制成LB膜,其在异相条件下的催化活性是均相条件下的25倍.     

环钯化合物在Suzuki偶联反应中的应用

因环钯化合物具有结构简单、性能稳定、反应活性高等优点,常被作为催化剂使用。总结了环钯化合物的合成方法及其在Suzuki偶联反应中的应用。     

环钯化合物在Heck反应中的应用研究

钯催化交叉偶联反应在化学工业、合成天然产物及生物活性物质中有着广泛的应用.催化剂体系是交叉偶联反应研究的核心.环钯化合物结构简单、性能稳定,在催化交叉偶联反应中具有高活性、高选择性,引起研究者们的极大关注,不断有新的环钯化合物被合成出来,其催化性能也得到了研究.本文综述了环钯化合物的合成方法及其在Heck反应中的应用.     

胺作为配体在钯催化偶联反应中应用

对近期我们研究小组及其它研究小组在利用胺作为钯催化偶联反应的配体研究进展进行了总结. 钯/胺作为催化体系主要应用的偶联反应包括: Suzuki-Miyaura交叉反应, Sonogashira交叉反应, Stille交叉反应, Hiyama交叉反应和Heck反应. 研究结果表明胺可以作为价廉和高效的配体促进钯催化交叉偶联反应.     

P⌒O环钯配合物的合成及对Suzuki交叉偶联反应的催化性能

P⌒O环钯配合物的合成及对Suzuki交叉偶联反应的催化性能;合成;二苯基膦丙酸钠;Suzuki偶联反应     

钯催化二溴代化合物自偶联环化合成二苯并[a,e]环辛四烯

由于独特的结构和广泛的应用,多取代环辛四烯及其苯并稠环衍生物的合成方法研究具有重要意义.本文报道了一种钯催化烯基溴化物与芳基溴化物的偶联反应.利用此钯催化的环化自偶联反应,以中等至较好的收率高选择性地从双溴代芳基或烯基化合物合成了多种二苯并[a,e]环辛四烯衍生物.     

环钯化合物在Heck反应中的应用研究

钯催化交叉偶联反应在化学工业、合成天然产物及生物活性物质中有着广泛的应用.催化剂体系是交叉偶联反应研究的核心.环钯化合物结构简单、性能稳定,在催化交叉偶联反应中具有高活性、高选择性,引起研究者们的极大关注,不断有新的环钯化合物被合成出来,其催化性能也得到了研究.本文综述了环钯化合物的合成方法及其在Heck反应中的应用.     

磁性纳米粒子负载钯催化剂在C-C键偶联反应中的应用

磁性纳米粒子(MNPs)负载钯催化剂因具有高的催化活性及易于原位磁分离回收等优点而得到快速发展,成为一类具有广泛应用前景的纳米催化剂,在学术及工业领域均受到广泛的关注。 本文对近年来MNPs负载钯催化剂在Suzuki、Heck等C-C偶联反应中的应用研究进行简要阐述,并对其发展前景进行了展望。     

负载钯催化的Suzuki偶联反应研究进展

负载钯催化的Suzuki偶联反应,由于产物易分离、催化剂可重复使用,已引起人们的广泛关注.综述了近年来负载钯催化的Suzuki偶联反应研究进展,载体包括活性碳、金属氧化物、硅铝酸盐微孔分子筛、二氧化硅材料、活性粘土和聚合物等.     

Pd（Ⅱ）／γ—Al2O3催化有机锡试剂和酰氯偶联反应的研究

有机锡试剂制备容易,活性适中,在钯的催化下和酰氯偶联,可以合成带有活性官能团的羰基化合物,因而引起了人们的重视。但是偶联反应通常使用的催化剂是PhCH_2(PPh_3)_2PdCl、Pd(PPh_3)_4,其制备繁锁;Pd(PPh_3)_4在空气中不稳定,易氧化;偶联反应结束后,钯以金属晶体析出,不能重复使用。因而,实际应用受到了限制。负载型钯催化剂已广泛     

Synthesis and microwave‐assisted catalytic activity of novel bis‐benzimidazole salts bearing furfuryl and thenyl moieties in Heck and Suzuki cross‐coupling reactions

A mixture of bis‐benzimidazole salts ( 1–7 ), Pd(OAc)₂ and K₂CO₃ in DMF ? H₂O catalyzes, in high yield, the Suzuki and Heck cross‐coupling reactions assisted by microwave irradiation in a short time. In particular, the yields of the Heck and Suzuki reactions with aryl bromides were found to be nearly quantative. The synthesized bis‐benzimidazole salts ( 1 – 7 ) were identified by ¹H? ¹³C NMR, IR spectroscopic methods and micro analysis. Copyright © 2010 John Wiley & Sons, Ltd.     

Suzuki and Heck coupling reactions mediated by palladium complexes bearing trans-spanning diphosphines

Palladium complexes of three trans-spanning diphosphines are examined for effecting C-C coupling reactions. Ten aryl halides of varying electron density were screened in Suzuki coupling reactions with phenylboronic acid and in Heck reactions with styrene. The results are discussed in terms of the unique flexibility and shape of the meta-terphenyl backbone upon which the diphosphine ligand is built.     

Highly ordered amphiphilic cyclopalladated arylimine self‐assembly films for catalyzing Heck and Suzuki coupling reactions

A series of new cyclopalladated arylimine compounds ( 3a , 3b , 3c , 4a , 4b , 4c ) were synthesized and characterized. Their catalytic properties for Heck and Suzuki coupling reactions in a homogeneous system were preliminarily investigated using water as solvent, in which no ligands, air isolation or assistant solvents were needed in cross‐coupling reactions. The optimization of the homogeneous system provided a basis for research on the heterogeneous catalytic reaction catalyzed by ordered self‐assembly films. Organized monolayers of 3a , 3b , 3c were prepared and utilized as C? C coupling catalysts. Monolayers of 3a , 3b , 3c were deposited using Langmuir–Blodgett techniques and analyzed using π–A isotherms, UV–visible and X‐ray photoelectron spectroscopies and atomic force microscopy, which showed near orientation on the surface and stability under the optimized experimental conditions suitable for exploring Heck and Suzuki coupling reactions. The activity of immobilized 3c monolayer is enhanced relative to homogeneous reaction, in which the ordered monolayers are efficient with a catalyst loading as low as 10^?5 mol%, turnover number as high as 79 200 and turnover frequency as high as 2640 h^?1. The catalytic efficiency is 100 times higher than that in the homogeneous case using the same amount and ratio of reagent. The increased activity of immobilized 3c monolayer is due to a combination of its structure and changes in conformation when deposited onto the substrate. The topographic changes of catalyst films, stability of films and catalytic activity were investigated with atomic force microscopy, cyclic voltammetry, X‐ray photoelectron spectroscopy and inductively coupled plasma atomic emission spectrometry, from which a heterogeneous catalytic mechanism for Suzuki coupling reaction is proposed. The study demonstrates that careful monolayer studies can provide useful models for the design and study of supported molecular catalyst systems. Copyright © 2016 John Wiley & Sons, Ltd.     

Carbon-Based Material-Supported Palladium Nanocatalysts in Coupling Reactions: Discussion on their Stability and Heterogeneity

Scientific interest in carbon-based materials (CBMs) has grown dramatically over the past few decades. Due to a variety of atomic orbital hybrid forms (sp, sp² and sp³ hybridization), carbon can form a variety of materials with diverse structures and characteristics. CBMs used as efficient catalyst supports show extensive promise in organic reactions, which is attributed to their structural similarity with organics, large specific surface area, chemical stability, and photocatalytic properties. This review presents the synthesis of CBM-supported palladium nanocatalysts based on impregnation, template methods, etc. The CBMs include activated carbon (AC), graphene, carbon nanotubes (CNTs), and their functionalized products, as supports for improving the activity and recyclability of simple Pd nanocatalysts. After surveying the literature where these catalysts have been utilized for carbon–carbon coupling reactions, there is a particular emphasis on Suzuki, Heck, and Sonogashira reactions. The catalytic mechanism of these Pd nanocatalysts (surface heterogeneous catalysis or homogeneous catalysis caused by Pd leaching) is discussed in detail, especially the effect of Pd leaching on the stability of the catalyst.     

The synthesis and catalytic properties of imidazolinium salts and their palladium(II) complexes

Three 1,3-dialkylimidazolinium chloride salts and their palladium(II) complexes have been synthesized and characterized by elemental analysis, ¹H NMR, ¹³C NMR and IR spectroscopy. The catalytic activities of the 1,3-dialkylimidazolinium chloride salts and their complexes in the Heck and Suzuki coupling reactions were investigated.     

Di(2-pyridyl)methylamine-palladium dichloride complex covalently anchored to a styrene-maleic anhydride co-polymer as recoverable catalyst for C-C cross-coupling reactions in water

A new polymer-supported di(2-pyridyl)methylamine-palladium dichloride complex covalently anchored to a styrene-alt-maleic anhydride co-polymer is prepared. This complex catalyzes Heck, Suzuki and Sonogashira cross-coupling reactions in neat water with similar efficiency than the monomeric complex. The turnover number (TON) of this polymer reaches up to 10⁴ for Heck reactions, whereas for Suzuki and Sonogashira couplings TONs up to 10⁵ are achieved. There is low leaching of palladium after filtration of the polymer and the activity remains almost constant after fourth and five reaction cycles especially in Sonogashira reactions. In the case of the Suzuki reaction Pd nanoparticles are dispersed into the polymer after the first cycle according to TEM images and 2.4% of Pd are found by ICP-OES in the corresponding filtrate. Alternatively, these palladium-catalyzed reactions can also be performed under microwave heating. These couplings take place with better efficiency with polymer-supported di(2-pyridyl)methylamine-palladium dichloride complex than with the polyurea-encapsulated Pd EnCat™ 40.     

Efficient synthesis of fluorinated biphenyl derivatives via Pd-catalyzed Suzuki coupling reactions in aqueous solvents at room temperature

A variety of fluorinated biphenyl derivatives were obtained in good yields in aqueous solvents at room temperature by Suzuki coupling reaction of aryl bromides and aryl boronic acid in the presence of high activity catalyst—some air-stable hemilabile PO coordinated cyclopalladated complexes. The structures of above catalysts were characterized by element analyses, IR, ¹H NMR, ¹³C NMR and ³¹P NMR.     

The Preparation of a New Kind of Carbosilane Dendrimer with 4‐(Naphthalen‐1‐yl)phenyl Core‐An Application of Suzuki Coupling Reaction

Using the divergent method, carbosilane dendrimers with p‐bromophenyl core were synthesized by using alternating Grignard and hydrosilylation reactions. And then, α‐naphthalenyl was connected to the core by using Suzuki coupling reaction. This gave a new carbosilane dendrimer with a 4‐(naphthalen‐1‐yl)phenyl core. All the products were characterized by IR, ¹H NMR, ¹³C NMR, ²⁹Si NMR, and MS. The study shows that Suzuki Coupling reaction is an effective and powerful core‐functionalization method and a satisfactory result can be achieved through prolonging the reaction time.     

Study on the Heck reaction promoted by carbene adduct of cyclopalladated ferrocenylimine and the related reaction mechanism

Carbene adduct of cyclopalladated ferrocenylimine has been successfully applied to Heck reaction of various aryl bromides with olefins. On the basis of kinetic studies, in situ ¹³C NMR spectra investigations and Hg poisoning experiments, it was proposed that the Heck reaction catalyzed by carbene adduct of cyclopalladated ferrocenylimine proceeded through a classical Pd(0)/Pd(II) cycle and such palladacycle was only a reservoir of the catalytically active Pd(0) species.     

Cross‐coupling reactions in water using ionic liquid‐based palladium(II)–phosphinite complexes as outstanding catalysts

Two new phosphinite ligands based on ionic liquids [(Ph₂PO)C₇H₁₄N₂Cl]Cl ( 1 ) and [(Cy₂PO)C₇H₁₄N₂Cl]Cl ( 2 ) were synthesized by reaction of 1‐(3‐chloro‐2‐hydoxypropyl)‐3‐methylimidazolium chloride, [C₇H₁₅N₂OCl]Cl, with one equivalent of chlorodiphenylphosphine or chlorodicyclohexylphosphine, respectively, in anhydrous CH₂Cl₂ and under argon atmosphere. The reactions of 1 and 2 with MCl₂(cod) (M = Pd, Pt; cod = 1,5‐cyclooctadiene) yield complexes cis‐[M([(Ph₂PO)C₇H₁₄N₂Cl]Cl)₂Cl₂] and cis‐[M(Cy₂PO)C₇H₁₄N₂Cl]Cl)₂Cl₂], respectively. All complexes were isolated as analytically pure substances and characterized using multi‐nuclear NMR and infrared spectroscopies and elemental analysis. The catalytic activity of palladium complexes based on ionic liquid phosphinite ligands 1 and 2 was investigated in Suzuki cross‐coupling. They show outstanding catalytic activity in coupling of a series of aryl bromides or aryl iodides with phenylboronic acid under the optimized reaction conditions in water. The complexes provide turnover frequencies of 57 600 and 232 800 h^?1 in Suzuki coupling reactions of phenylboronic acid with p‐bromoacetophenone or p‐iodoacetophenone, respectively, which are the highest values ever reported among similar complexes for Suzuki coupling reactions in water as sole solvent in homogeneous catalysis. Furthermore, the palladium complexes were also found to be highly active catalysts in the Heck reaction affording trans‐stilbenes. Copyright © 2014 John Wiley & Sons, Ltd.