Copper-catalyzed direct preparation of diaryl sulfides from aryl iodides using potassium thiocyanate as a sulfur transfer reagent

A method for direct preparation of diaryl sulfides from aryl iodides using potassium thiocyanate as a sulfur-transfer agent is reported. A catalyst system comprising of a simple copper salt, tetrabutylammonium bromide as a phase-transfer agent and water as the solvent is used. Microwave heating at 200 °C for 60 min allows for the conversion of a range of aryl iodides to the corresponding diaryl sulfides.     

An efficient method for the N-arylation of phenylurea via copper catalyzed amidation

The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable CuI,N,N-dimethylethylenediamine as a ligand,and K₃PO₄ as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields.This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligands.     

N-arylation of indoles with aryl halides using copper/glycerol as a mild and highly efficient recyclable catalytic system

A simple, efficient, and inexpensive copper catalyzed protocol has been developed for cross-coupling of indoles with aryl halides by using glycerol as a green recyclable solvent and DMSO as an additive. The reaction was carried out at low catalyst loading furnishing various N-aryl indoles in good to excellent yield. This copper/glycerol mixture was recycled up to four runs without any loss in its catalytic activity.     

One-pot synthesis of aryl alkyl thioethers and diaryl disulfides using carbon disulfide as a sulfur surrogate in the presence of diethylamine catalyzed by copper(I) iodide in polyethylene glycol (PEG200)

A copper catalyzed one-pot protocol for the preparation of aryl alkyl thioethers and diaryl disulfides using carbon disulfide as the sulfur source and diethylamine in polyethylene glycol (PEG200) is described.     

水溶性氮杂环卡宾钯金属配合物催化的Sonogashira反应

成功合成了一种磺酸钠基团官能团化的水溶性氮杂环卡宾钯金属配合物。在无膦、以水作溶剂的反应条件下,这种水溶性卡宾钯金属配合物能高效催化碘代芳烃和端基炔烃的Sonogashira偶联反应,反应结束后,可以通过萃取的方式把催化剂从反应混合物中分离出来,该催化剂可以重复循环使用四次。     

Palladium catalyzed alkynylation of aryl halides (Sonogashira reaction) in water

The palladium catalyzed alkynylation of aryl halides (Sonogashira reaction) has been achieved in pure water without any additives or phase transfer catalysts. The reaction, which requires only 0.5 mol % of Pd(PPh₃)₄ catalyst, is remarkably fast (30 min at 70 °C) producing high yields of the aryl alkyne products.     

Environmentally friendly organic synthesis using bismuth compounds: bismuth(III) iodide catalyzed deprotection of acetals in water

The chemoselective deprotection of a wide range of acetals and ketals in water is catalyzed by bismuth(III) iodide. Bismuth(III) compounds are remarkably nontoxic and hence are attractive as environmentally friendly catalysts.     

Sulfonyl Ketenimines as Key Intermediates in One‐Pot Synthesis of N‐Sulfonyl‐2‐alkaneimidoyl Selenocyanates

Sulfonyl‐ketenimine intermediates, generated by the addition of Cu acetylides to sulfonyl azides, are trapped by KSeCN to afford N‐sulfonyl‐2‐alkaneimidoyl selenocyanates in moderate‐to‐good yields.     

Copper catalyzed N-arylation between aryl halides and nitriles in water: an efficient tandem synthesis of benzanilides

A series of benzanilide compounds were synthesized through copper-catalyzed tandem reactions. With the assistance of ionic liquid as phase transfer catalyst, aryl halides, and nitriles underwent a hydrolysis/coupling pathway to form benzanilides in water. Advantages of this reaction include the use of water as the environmental friendly solvent, short reaction time, and the tolerance of various functional groups. A proposed mechanism based on control experiments is also presented.     

Potassium iodide catalyzed reductive dehalogenation ofα-halo-ketones using Hantzsch ester diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate as reductant

<正>In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate(DHP) and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone media.The procedure presented here showed several merits such as short reaction time,practical experimental and isolated procedure,and excellent yields of products.     

Amide as an efficient ligand in the palladium-catalyzed Suzuki coupling reaction in water/ethanol under aerobic conditions

Amide,which is derived from proline and is inexpensive and air-stable,has been synthesized and characterized by ¹H NMR,¹³C NMR,and MS.It was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling reaction.In the Pd/amide catalytic system,aryl bromides can be coupled with phenylboronic acid in ethanol/water（1:2;v/v） in excellent yields even with a low Pd loading of 0.01 mol%.Moreover,the scope of the reaction is broad,and a wide variety of functional groups are tolerant.     

Convenient and efficient Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions catalyzed by 1,3,4-trisubstituted-1,2,3-triazolium iodide and palladium salt systems

A series of 1,3,4-trisubstituted-1,2,3-triazolium iodide salts (4a–c) were synthesized via a three-step reaction sequence. Corresponding anilines (1a–c) were converted to azides (2a–c) which were then treated with phenylacetylene with “Click” chemistry to access 1,4-disubstituted-1,2,3-triazoles (3a–c). Subsequent methylation of 1,4-disubstituted-1,2,3-triazoles (3a–c) yielded 1,3,4-trisubstituted-1,2,3-triazoliumiodide salts (4a–c) in appreciable yields. All the synthesized compounds were characterized by ¹H and ¹³C NMR, ATR–IR spectroscopic techniques and elemental analyses. Additionally, the structure of 1-(4-chlorophenyl)-4-phenyl-1,2,3-triazole (3b) was confirmed by single crystal X-ray diffraction analysis. The catalytic activity of 4a–c in a catalytic system consisting of 1,3,4-trisubstituted-1,2,3-triazoliumiodide salt/palladium(II) acetate/base were investigated toward Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions. The Suzuki–Miyaura cross-coupling reactions were carried out under mild reaction conditions with good to excellent yields, whereas Heck–Mizoroki cross-coupling reactions were performed at elevated temperature with moderate yields. Further, in situ method skips the synthetic procedure of preparing the palladium(II) complexes and hence is more economical and less tedious.     

Amination of aryl chlorides in water catalyzed by cyclopalladated ferrocenylimine complexes with commercially available monophosphinobiaryl ligands

The easily accessible, air- and moisture-stable cyclopalladated ferrocenylimine complex 3 was found to be a highly active one-component precatalyst for the amination of aryl chlorides in water in the presence of inexpensive KOH and t-BuOH as a base and an additive, respectively.     

New strategy for the synthesis of N-aryl pyrroles: Cu-catalyzed C-N cross-coupling reaction of trans-4-hydroxy-l-proline with aryl halides

trans-4-Hydroxy-l-proline is used for the first time as an effective nucleophilic coupling partner with aryl halides mediated by copper iodide with Cs₂CO₃ as the base and DMSO as the solvent. Utilizing this protocol cross-coupling of trans-4-hydroxy-l-proline with a wide variety of substituted aryl halides to produce N-aryl pyrroles in moderate to good yields.     

Homocoupling of arylboronic acids and potassium aryltrifluoroborates catalyzed by protein-stabilized palladium nanoparticles under air in water

Palladium nanoparticles stabilized primarily within the protein cavity of a highly thermostable Dps protein (DNA binding protein from starved cells) from the thermophilic bacterium Thermosynechoccus elongatus provide an efficient catalyst for the homocoupling of boronic acids and potassium aryltrifluoroborates in water under aerobic phosphine-free conditions. Symmetrical biaryls have been isolated in good to excellent yields. Potassium aryltrifluoroborates give similar or better results than the corresponding arylboronic acids.     

Transition metal catalyzed cross-coupling of aryl Grignard reagents with aryl fluorides via Pd- or Ni-activation of the C-F bond: an efficient synthesis of unsymmetrical biaryls - application of microwave technology in ligand and catalyst screening

Biaryl compounds are prevalent in both nature and in active pharmaceutical ingredients. The palladium and nickel catalyzed cross-coupling of aryl Grignard reagents with aryl fluorides reported herein affords moderate to excellent yields of the corresponding unsymmetrical biaryls. In addition, the first example of a biaryl cross-coupling utilizing unactivated aryl fluorides under phosphine free palladium conditions is reported. Microwave technology allowed rapid optimization of catalyst systems, which identified several ligands for this cross-coupling reaction.     

Heterogeneous Suzuki and copper-free Sonogashira cross-coupling reactions catalyzed by a reusable palladium(II) complex in water medium

A new polystyrene anchored Pd(II) azo complex has been synthesized and characterized. The present Pd(II) azo complex behaves as a very efficient heterogeneous catalyst in the Suzuki coupling and Sonogashira coupling reaction in water medium. Aryl halides, coupled with phenylboronic acids (Suzuki-Miyaura reaction) or terminal alkyne (Sonogashira reaction), smoothly afford the corresponding cross-coupling products in excellent yields (83-100% yield for Suzuki reaction and 68-96% yield for Sonogashira reaction of aryl halides) under phosphine-free reaction conditions in the presence of polystyrene anchored Pd(II) azo complex catalyst in water medium. Furthermore, the catalyst has shown good thermal stability and recyclability. This polymer-supported Pd(II) catalyst could be easily recovered by simple filtration of the reaction mixture and reused for more than six consecutive trials without a significant loss of its catalytic activity.     

2-Aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent

In this article, we have introduced application of 2-aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent. By using 2-aminophenyl diphenylphosphinite as a ligand and Pd(OAc)₂ as the pre-catalyst, structurally different aryl halides (I, Br, Cl) were reacted efficiently with phenylboronic acid in water to produce their corresponding biphenyl products in good to excellent yields under heterogeneous conditions. The catalyst is recyclable and was recycled for seven runs for the reaction of bromobenzene with phenylboronic acid without appreciable loss of its catalytic activity.     

2-Aminophenyl diphenylphosphinite as a new ligand for heterogeneous palladium-catalyzed Heck-Mizoroki reactions in water in the absence of any organic co-solvent

In this article, 2-aminophenyl diphenylphosphinite has been introduced as a new ligand for the Heck-Mizoroki reactions of aryl halides with styrene and n-butylacrylate in water in the presence of palladium acetate. This ligand is easily prepared from the reaction of chlorodiphenyl phosphine with 2-aminophenol in high yield. Pre-catalyst [Pd(OAc)₂] in the presence of the ligand produces a black solid mass. The solid catalyst has been recycled for the reaction of bromobenzene with styrene for six runs without appreciable loss of its catalytic activity.