Simultaneous reduction of nitro- to amino-group in the palladium-catalyzed Suzuki cross-coupling reaction

An efficient method for palladium-catalyzed Suzuki cross-coupling reaction with simultaneous reduction of nitro- to amino-group has been developed. This method allows nitro-substituted aryl halides to readily react with arylboronic acids, to afford aryl substituted aniline in low to excellent yields. The reaction was catalyzed by Pd(OAc)₂ (3 mol %) at 150 °C under atmospheric pressure in the presence of K₂CO₃ (3 equiv) in DMF/H₂O (5/1).     

水介质中高分子配体负载微粒钯催化Suzuki偶联反应

对Wang树脂进行改性,制备了高分子负载纳米钯催化剂,并将其应用于水介质中卤代芳烃与芳硼酸的Suzuki偶联反应。 以溴苯和苯硼酸的偶联反应为模型,考察了溶剂、温度、碱种类、催化剂用量对反应的影响,确定较佳的反应条件为：n(C₆H₅Br)∶n(C₆H₅B(OH)₂)∶n(WRP-Pd)∶n(K₂CO₃)∶n(TBAB)=1.0∶1.5∶0.005∶2.0∶0.5,反应温度100℃, 反应时间4 h。 用氯代芳烃代替溴代芳烃反应时,延长反应时间,也能得到较高产率。 催化剂经过简单的过滤洗涤后,重复使用4次活性无明显降低。     

Aryl-guanidine/Pd-catalyzed Suzuki Cross-coupling Reaction at Room Temperature

Four aryl-guanidines(AG)were synthesized and used for the palladium-catalyzed Suzuki cross-coupling reaction to test the catalytic activity.In the presence of steric bulk AG,when aryl bromide and arylb...     

Palladium-catalyzed Suzuki cross-coupling reactions in a microemulsion

An enhancement of palladium-catalyzed Suzuki cross-coupling reactions between substrates possessing long-chain alkyl or oxyalkyl substituents in two-phase media, in the presence of sodium dodecylsulfate, is shown. Quantitative evaluations of the influence of SDS on the reaction rates were determined.     

Microwave-assisted Palladium-micelle-catalyzed Suzuki Cross-coupling Reaction in Water

A microwave-accelerated Suzuki coupling procedure was developed via guanidinium ionic liquids(GILs) stabilized Pd-micelle.The Pd micelle/GILs play a key role in enhancing the activity,due to the highly dispersed Pd active sites and the phase transfer function of GILs,which ensures the adsorption of reactants and facilitates the translation of the intermediates to the surface of the micelle.     

Ferrocenyl iminophosphine ligands in Pd-catalysed Suzuki couplings

A mixture of Pd₂(dba)₃/{η-C₅H₄CHN[CH(CH₃)(Nap)]}Fe[η-C₅H₄P(^tBu)₂] efficiently catalyzes the Suzuki reactions of a variety of bulky aryl halides and aryl- and alkyl-boronic acids, affording the desired cross-coupling biaryl products in quantitative isolated yields under mild conditions and at low (1 × 10⁻⁶-1 mol%) Pd loadings. Spectroscopic (NMR & ESI) analysis of the mixture of Pd₂(dba)₃, the hybrid [P,N] ligands, and aryl halides revealed different structural forms of oxidative addition products that are dependent on the substituent on the imino nitrogen.     

Microwave-promoted Palladium Catalyzed Suzuki Cross-coupling Reaction in Water

Suzuki coupling is probably the most versatile approach among the cross-coupling reactions and the reaction has long been the subject of intensive work in the area of transition-metal chemistry1. In recent years, various modifications involving the catalyst, solvents, bases, reaction conditions and synthetic technique have been developed 2. The Suzuki cross-coupling reaction in water is more safe, economical. It is an environmentally friendly alternative in organic synthesis. The use of w…     

Palladium Catalyzed Suzuki Cross-coupling Reaction in Molten Tetra-n-butylammonium Bromide

A practical procedure for palladium catalyzed Suzuki cross-coupling reaction of arylboronic acids with aryl halides, including aryl chlorides in molten tetra-n-butylammonium bromide (TBAB) was developed. The reaction exhibits high efficiency and functional group tolerance. The recovery of the catalyst and molten n-Bu4NBr was also investigated.     

Synthesis and application of ortho-palladated complex of (4-phenylbenzoylmethylene)triphenylphosphorane as a highly active catalyst in the Suzuki cross-coupling reaction

The ortho-metallated complex [Pd(μ-Cl){κ₂(C,C)-[C₆H₄(PPh₂CHC(O)C₆H₄-Ph-4)}]₂ (2a) was prepared by refluxing of Pd(OAc)₂ and {(Ph)₃PCHCOC₆H₄-Ph-4} (PhBPPY) of in CH₂Cl₂ followed by addition of an excess of KCl in MeOH Complex (2a) reacts with triphenylphosphine to give the mononuclear derivative [Pd(Cl)(PhC₆H₄COCHPPh₂C₆H₄)(PPh₃)] (3a) whose crystal structure has been determined by single crystal X-ray diffraction. The Suzuki reactions of aryl bromides and chlorides of varying electron density using complex (3a) as an efficient catalyst were performed, giving the cross-coupling products in good to excellent yields.     

Chitosan-supported palladium(0) catalyst for microwave-prompted Suzuki cross-coupling reaction in water

A chitosan-supported palladium (Pd) (0) catalyst was prepared by simple adsorption of palladium(II) ion onto chitosan beads and a subsequent reduction process. To maintain mechanical stability, the chitosan-supported palladium(0) catalyst was cross-linked with either glutaraldehyde or diglycidyl ether polyethylene glycol. The catalysts were utilized for the Suzuki cross-coupling reaction in water. The catalyst, in the presence of a tetrabutylammonium bromide (TBAB) additive, showed excellent catalytic activity in microwave-prompted Suzuki cross-coupling reactions using various aryl halides and boronic acids. In addition, the catalyst was successfully reused up to five times without significant loss of catalytic activity.     

新型四齿膦配体在钯催化的Suzuki偶联反应中的应用

由廉价易得的1,2-环己二胺作为起始原料,通过简单的合成步骤制备了一种新型的四齿膦配体1,并将该配体应用于钯催化的Suzuki交叉偶联反应中.在仅为0.1 mol%的催化剂用量下,成功地实现了多种氯/溴代芳烃、氯/溴代杂环芳烃以及溴代烷烃底物与苯硼酸的交叉偶联反应,产率最高可达99%.     

钯催化氟磺酸酚酯Suzuki反应合成三联苯类化合物

发展了一个高效、简便合成三联苯类化合物的方法。以氯化钯为催化剂,碳酸钾与三乙胺为碱,无需加入任何配体,在乙醇水溶液中催化氟磺酸联苯酚酯与芳基硼酸的Suzuki反应,可高效合成含有多种官能团的三联苯类化合物。该方法操作简便,无需氮气保护;且芳基硼酸自偶联副产物少,有利于产品的分离。为三联苯类化合物的合成提供了一条简便而高效的途径。     

Preparation of monodentate phosphinite ligands: their applications in palladium catalyzed Suzuki reactions

Two phosphinites 2,6-OMe, 4-Me, 1-OPR₂C₆H₂ (5a: R=Ph; 5b: R=^tBu) were prepared in good yields. Two methoxy groups are placed on the 2,6 positions of the phosphinites deliberately thereby to avoid a plausible orthometallation process while coordinating toward palladium metal. Further reaction of 5a with PdCl₂ in the ratio of 2:1 and 1:1 gave 5a ligated palladium complexes {(5a)PdCl(μ-Cl)}₂7a and {(5a)₂PdCl₂} 8a, respectively. As revealed from their crystal structures, the former is a dimeric complex with anticipated molecular arrangement; nevertheless, the latter is a monomeric complex with unexpected, energetically unfavorable cis form. By contrast, only dimeric form was observed from the reaction of 5b with PdCl₂. It is believed that the bulky substituents, ^tBu, on 5b prevent the formation of a monomeric complex in cis form. Fair to good efficiencies were observed for the Suzuki-Miyaura cross-coupling reactions employed in situ-prepared 5/Pd(OAc)₂ as the catalytic precursor.     

光催化Suzuki偶联反应的非均相催化剂研究进展

Suzuki偶联反应作为构建C-C键的最有效的手段之一,在医药、染料和电子工业等领域扮演着重要的角色.近年来,光催化技术和绿色有机合成化学蓬勃发展,利用可再生的太阳能光催化Suzuki偶联反应不但可以解决在催化反应过程中的能源与环境问题,还可以在温和条件下高产率地获得联苯化合物.与均相光催化剂相比,非均相光催化剂具有良...     

Study on the electronic effects on stereoconservativity of Suzuki coupling in chiral groove of binaphthyl

Suzuki diarylation of enantiopure 2,2′-diiodo-1,1′-binaphthyl catalyzed by triphenylphosphane palladium complex is accompanied by almost complete racemization of binaphthyl moiety (7% e.e.). Based on formerly proposed mechanism, secondary oxidative addition of Pd(II) to Pd(IV)-complex, competitive to transmetallation, is expected to be responsible for racemization. In accordance with it, racemization pathway can be suppressed in the favour of stereoconservative route by electronic factors, which control the rate of oxidative addition. Among the electronic factors, decreasing donating ability of the tested phosphane ligands resulted in increase of e.e. of the diarylated product up to 65%, using triindol-1-ylphosphane. However, this factor slows down also the rate of the primary oxidative addition that lowers the yield of the diarylated product. Further decrease in donating ability of the ligand makes palladium complex almost inactive in this cross-coupling reaction. Effect of the leaving group of binaphthyl 2,2′-dielectrophile (as a matter of the reactivity of C-X bond towards oxidative addition) was found to be even more dramatic: almost stereoconservative route in case of 2,2′-dibromo-1,1′-binaphthyl (95% e.e.), but no reaction in case of corresponding ditriflate.     

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.     

Integrated Suzuki Cross-Coupling/Reduction Cascade Reaction of meta-/para-Chloroacetophenones and Arylboronic Acids under Batch and Continuous Flow Conditions

Overcoming the incompatibility of a pair of conflicting catalysts via a flow methodology has great significance in the practical applications for multistep organic transformations. In this study, a multiple continuous-flow system is developed, which can boost the reactivity and selectivity in a sequential enantioselective cascade reaction. During this process, a periodic mesoporous organosilica-supported Pd/carbene species as a Suzuki cross-coupling catalyst is packed in the first column reactor, whereas another periodic mesoporous organosilica-supported Ru/diamine species as an asymmetric transfer hydrogenation catalyst is packed in the second column reactor. As we envisioned, the initially Pd-catalyzed cross-coupling reaction of meta-/para-chloroacetophenones and aryl boronic acids followed by the subsequentially Ru-catalyzed reduction provides chiral biarylols with enhanced yields and enantioselectivities. Furthermore, the advantages of the easy handling and the simple procedure make this system an attractive application in a scale-up preparation of optically pure organic molecules under environmentally-friendly conditions.     

The palladium(0) Suzuki cross-coupling reaction as the key step in the synthesis of aporphinoids

We report a flexible approach to the total synthesis of 4,5-dioxoaporphines based on the palladium(0) catalyzed Suzuki cross-coupling of phenylboronic acids with sterically hindered 2-bromo phenyl acetates or bromo phenyl acetamides, followed by sequential bicyclization of biarylacetamides promoted by oxalyl chloride/Lewis acid. The reduction of 4,5-dioxoaporphines provides a chemoselective entry to aporphines, dehydroaporphines and 4-hydroxy-dehydroaporphines. A three-steps total synthesis for (±)-O,O′-dimethylapomorphine from readily accessible precursors is also reported.     

Palladium-catalyzed one-pot Suzuki coupling followed by arylpalladium addition to aldehyde: a convenient route to fluoren-9-one derivatives

Various fluoren-9-one derivatives were prepared efficiently by a one-pot reaction involving sequential Suzuki coupling of 2-bromophenyl boronic acid with 2-bromocarboxaldehyde followed by intramolecular arylpalladium addition to aldehyde.     

Synthesis of 3-hetarylpyrroles by Suzuki–Miyaura cross-coupling

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