PHOTOINDUCED S_(RN)1 REACTIONS OF ARYL HALIDES WITH CARBAZOLYL NITROGEN ANION

The photoinduced reactions of aryl halides with carbazolyl nitrogen anion,in dimethyl sulfoxide,yield the corresponding N-arylated products.These reactions are suggested in terms of the S;Nl mechaism of nucleophilic substitution.

Dehalogenation of Aryl Halides Catalyzed by Montmorillonite Immobilized Bimetal Catalyst in Aqueous System

A novel bisupported bimetal catalyst PVP-PdCl2-FeSO4/Al-Mont-PEG600 was prepared by immobilization of PVP （poly （N-vinyl-2-pyrrolidone）） supported bimetallic catalyst using alumina pillared inartificial montmorillonite as the carrier. This catalyst has good dehalogenation activity and selectivity to aryl halides o-chlorotoluene in aqueous system in the presence of phase transfer catalyst （PEG） and sodium formate as hydrogen source. The catalyst also shows good reusability.

THE SPIN DELOCALIZATION SUBSTITUENT PARAMETER σ 10. SYNTHESIS OF SUBSTITUTED α, β, β-TRIFLUOROSTYRENES BY THE Pd-CATALYZED CROSS-COUPLING OF TRIFLUOROVINYLZINC BROMIDE WITH ARYL HALIDES

Palladium-catalyzed coupling of trifluorovinylzinc reagent with substituted aryl halides Y-C_6H_4-X (Y=p-NO_2, p-and m-COOMe, p-COOH, p-CONH_2, p- and m-CN; X=Br, I, Cl) provides a synthetic method for α, β, β-trifluorostyrenes(Y-TFS's). A series of previously unavailable Y-TFS's were thus obtained.

Cu_2O/SiC as efficient catalyst for Ullmann coupling of phenols with aryl halides

A Cu2O/SiC heterogeneous catalyst was prepared via a two‐step liquid‐phase method using diethyleneglycol as both the solvent and the reducing agent.The catalyst was characterized using X‐raydiffraction,X‐ray photoelectron spectroscopy,scanning electron microscopy(SEM),transmissionelectron microscopy(TEM),and H2temperature‐programmed reduction.All the results indicatethat Cu is present on the SiC support primarily as Cu2O.The SEM and TEM results show that cubicCu2O nanoparticles are uniformly dispersed on theβ‐SiC surface.The reaction conditions,namelythe temperature,reaction time,and amounts of base and catalyst used,for the Ullmann‐type C–Ocross‐coupling reaction were optimized.A model reaction was performed using iodobenzene(14.0mmol)and phenol(14.0mmol)with Cu2O/SiC(5wt%Cu)as the catalyst,Cs2CO3(1.0equiv.)as thebase,and tetrahydrofuran as the solvent at150°C for3h;a yield of97%was obtained and theturnover frequency(TOF)was1136h?1.The Cu2O/SiC catalyst has a broad substrate scope and canbe used in Ullmann‐type C–O cross‐coupling reactions of aryl halides and phenols bearing a varietyof different substituents.The catalyst also showed high activity in the Ullmann‐type C–Scross‐coupling of thiophenol with iodobenzene and substituted iodobenzenes;a TOF of1186h?1was achieved.The recyclability of the Cu2O/SiC catalyst in the O‐arylation of phenol with iodobenzenewas investigated under the optimum conditions.The yield decreased from97%to64%afterfive cycles.The main reason for the decrease in the catalyst activity is loss of the active component,i.e.,Cu2O.

Synthesis of α-Arylated Esters from Aryl Halides

An operationally simple and inexpensive catalyst system was developed for the cross coupling of aryl iodides and bromides with ethyl acetoacetate by using CuI as catalyst and Nmethyl glycine as ligand. The reaction represents a novel Cu-catalyzed C-C cross coupling reaction. This procedure is applicable to the preparation of pharmaceutically important α- arylalkanoic acids.

An Efficient Synthesis of Diaryl Ethers by Coupling Aryl Halides with Substituted Phenoxytrimethylsilane in the Presence of TBAF

A general synthesis of diaryl ethers via coupling of aryl halides with substituted phenoxytrimethylsilane in the presence of TBAF is described. The protocol is simple and mild, and gives good to excellent yields.

Dehalogenation of Aryl Halides Catalyzed by MontK10 Immobilized PVP-Pd-Sn Catalyst in Aqueous System

A series of PVP-Pd-Sn/MontK10 catalysts were prepared by immobilization of PVP[poly(N-vinyl-2-pyrrolidone)] supported bimetallic catalyst using MontK10 as carrier. This catalyst has good catalytic activity for hydrogen transfer dehalogenation of aryl halides. The catalytic reaction was carried out in aqueous system in the presence of phase transfer catalyst and sodium formate as hydrogen source. The catalyst with loading Pd 0.19wt% and molar ratio of Pd/Dn 8:1 gives the highest activity and good stability. This catalyst is more reducible with NaBH4. It is also found that the catalyst is easily separated from the reaction system.

A facile approach to asymmetrical biaryls via coupling reaction of aryl halides with sodium tetraphenylborate catalyzed by MCM-41-supported sulfur palladium(0) complex

Various functionalized asymmetrical biaryls can be synthesized in high to excellent yields via coupling reaction of aryl iodides or bromides with NaBPh4 catalyzed by MCM-41-supported sulfur palladium（0） complex. This palladium complex can be easily recovered and reused many times without loss of activity.

Copper-Catalyzed Amination of Aryl Halides with Aqueous Ammonia under Mild Conditions

A Cu（I） generated in situ from CuSO4.5H2O/sodium ascorbate catalyzed cross-coupling reaction of aryl halides with aqueous ammonia for the synthesis of primary aromatic amines has been developed. Key to the success in- cluded the application of aqueous ammonia under a homogeneous condition.

Copper-catalyzed N-arylation of 2-arylindoles with aryl halides

10 mol% Cul combined with the DMEDA ligand can efficiently catalyze the N-arylation of 2-arylindoles with aryl iodides and aryl bromides in good to excellent yields. The aryl halides bearing electron-rich or electron-deficient functional groups can be well tolerated under this mild reaction conditions.

Facile and Economical Electrochemical Dehalogenative Deuteration of(Hetero)Aryl Halides

Deuterated compounds are valuable in synthetic,pharmaceutical,and analytical chemistry.The deuteration of halides is a widespread method for highly site-selective deuterium installation.However,the facile,efficient,and economical deuterium incorporation remains challenging.In this work,we introduced a practical deuteration of(hetero)aryl halides through an electrochemical reduction method.This transformation proceeded smoothly at room temperature without metal catalysts,external reductants,or toxic or dangerous reagents.Remarkably,low-cost and chemically equivalent D2O was the sole deuterium source in this reaction.Professional electrosynthesis equipment was not essential because we demonstrated common batteries and electrodes were enough for this reaction.

Monodentate phosphorus-coordinated palladium(Ⅱ)complexes as new catalyst for Mizoroki-Heck reaction of aryl halides with electron-deficient olefins

Four novel palladium（（Ⅱ）） complexes coordinated by phosphorus atoms from both 3,5-disubstituted-1H- 1,2,4-diazaphospholes in monodentate fashion were developed as efficient catalyst for the Mizoroki- Heck reaction of aryl halides with electron-deficient olefins. The coupling reaction of awl halide bearig different functional groups with olefin derivatives took place and the corresponding products were isolated in good to excellent yields under optimal conditions. The procedure exhibits good functional group tolerance and wide substrate scope. This Mizoroki-Heck reaction was further achieved using Pd（OAc）2 and 3,5-di-isopropyl-1H-1,2,4-diazaphospholes as combined catalyst, which provide the convenient and alternative method in organic synthesis

Cu/Picolinamides-Catalyzed Coupling of (Hetero) aryl Halides with Secondary Phosphine Oxides and Phosphite

Some 4-hydroxy-picolinic acid derived amides were revealed as more efficient ligands for Cu-catalyzed coupling of(hetero)aryl halides with secondary phosphine oxides and phosphites.Only 3—5 mol%CuI and ligands were required to ensure coupling with a number of(hetero)aryl bromides and iodides to complete at 120 ℃ in 10—20 h.

Microwave assisted,ligand free,copper catalyzed reaction of aryl halides with phenyl urea

The ligand free coupling reaction of phenyl urea with different functionalized aryl halides in the presence of air stable Cu_2O and t-BuOK 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 ligand.

Palladium-Catalyzed Suzuki-Miyaura Type Coupling Reaction of Aryl Halides with Triphenylborane-Pyridine

The Suzuki-Miyaura type coupling reaction of aryl halides with triphenylborane-pyridine was described. The reaction can be catalyzed by Pd（OAc）2 （5 mol%） in presence of Cs2CO3 at 50 ℃ or 80 ℃, and functionalized biaryls were obtained in good to excellent yields. This protocol is general and can tolerate a wide range of func- tional groups.

Green Recyclable CuO-CeO_(2)Nanocomposite Catalyzed Amination of Aryl Halides with Aqueous Ammonia in Water

CuO-CeO_(2)nanocomposite as a green recyclable catalyst,catalyzed amination of aryl halides with aqueous am-monia in water.This catalyst can be easily recovered by simple filtration and recycled up to 5 consecutive runs with consistent activity.The procedure provides some advantages such as simple work-up,clean procedure,relatively short reaction times and high yields of the products.

Direct synthesis of diaryl sulfides by copper-catalyzed coupling of aryl halides with aminothiourea

An efficient and simple protocol of copper-catalyzed C-S bond formation between aryl halides and inexpensive and commercially available aminothiourea is reported.A variety of symmetrical diaryl sulfides can be synthesized in good to excellent yields up to 94%with the advantage of avoiding foul-smelling thiols.

Palladium-catalyzed Coupling between Aryl Halides and Trimethylsilylacetylene Assisted by Dimethylaminotrimethyltin

Palladium-catalyzed coupling between aryl halides, especially less reactive ones or N-heteroaryls, and trimethylsilylacetylene in the presence of dimethylaminotrimethyltin generated the coupled products in high yields. The reaction does not need CuI and base as auxiliary agents.

Direct N-Arylation of Azaheterocycles with Aryl Halides under Ligand-free Condition

A simple and efficient C--N cross-coupling method of aryl halides with various heterocycles was reported, by using 10 tool% of CuI as catalyst and 1.2 equiv. Nail as base. Aryl iodides, aryl bromides and many substituted atyl chlorides could efficiently react with heterocycles, providing variety of N-arylated products in good to excellent yields. The ligand-free catalyst system was stable in air and could be readily reused.

Suzuki Coupling Reaction Catalyzed by Cyclopalladated Complexes of Tertiary Arylamines in Ionic Liquid

Suzuki cross-coupling reaction of phenylboronic acid with aryl halides catalyzed by cyclopalladated complexes of tertiary arylamines immobilized in ionic liquid [Bmim]^＋BF4^- was reported. The catalytic system proved to be efficient and be reused at least 3 times without significant loss of activity.