- Mizoroki–Heck Cross-Coupling of Acrylate Derivatives with Aryl Halides Catalyzed by Palladate Pre-Catalysts
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The Mizoroki–Heck (MH) reaction involving aryl halides with various acrylates and acrylamides has been studied using air and moisture-stable imidazolium-based palladate pre-catalysts. These pre-catalysts can be converted into Pd-NHC species (NHC = N-heterocyclic carbene) under catalytic conditions and are capable of facilitating the Mizoroki–Heck reaction of aryl halides with various acrylates. The effects of solvent, catalyst loading, temperature and bases on the reaction outcome have been investigated. Various coupling partners were tolerated under the optimal reaction conditions catalyzed by palladate 1, [SIPr·H][Pd(η3-2-Me-allyl)Cl2]. The efficiency of the optimized synthetic methodology was tested on various aryl halides and substituted acrylates as well as acrylamides. The MH reaction yielded the coupled products in good to excellent isolated yields (up to 98%).
- Islam, Mohammad Shahidul,Nahra, Fady,Tzouras, Nikolaos V.,Barakat, Assem,Cazin, Catherine S. J,Nolan, Steven P.,Al-Majid, Abdullah Mohammed
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- Fe-MIL-101 modified by isatin-Schiff-base-Co: a heterogeneous catalyst for C-C, C-O, C-N, and C-P cross coupling reactions
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A metal-organic framework functionalized with a cobalt-complex is preparedviapost-synthetic modification of Fe-MIL-101-NH2. Initially, Fe-MIL-101-NH2reacted with isatin to produce Fe-MIL-101-isatin-Schiff-base, which can anchor the cobalt by the addition of cobalt acetate. The resulting MOF-Co catalyst is characterized by employing multiple techniques. This new modified MOF acts as a heterogeneous and recyclable catalyst for efficient Ullmann, Buchwald-Hartwig, Hirao, Hiyama and Mizoroki-Heck cross-coupling reactions of several aryl halides/phenylboronic acid/phenyltosylate with phenols, anilines/heterocyclic amines, triethyl phosphite, triethoxyphenylsilane and alkenes and generates the expected coupling products in good to high yields.
- Farrokhi, Alireza,Rouzifar, Majid,Sansano, José Miguel,Sobhani, Sara
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p. 19963 - 19976
(2021/11/12)
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- Discovery of a novel inhibitor of nitric oxide production with potential therapeutic effect on acute inflammation
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Inflammation as a host's excessive immune response to stimulation, is involved in the development of numerous diseases. To discover novel anti-inflammatory agents and based on our previous synthetic work on marine natural product Chrysamide B, it and a series of derivatives were synthesized and evaluated for their anti-inflammatory activity on inhibition of LPS-induced NO production. Then the preliminary structure–activity relationships were conducted. Among them, Chrysamide B is the most potent anti-inflammatory agent with low cytotoxicity and strong inhibition on the production of NO (IC50 = 0.010 μM) and the activity of iNOS (IC50 = 0.082 μM) in LPS-stimulated RAW 264.7 cells. Primary studies suggested that the mechanism of action may be that it interfered the formation of active dimeric iNOS but not affected transcription and translation. Furthermore, its good performance of anti-inflammatory effect on LPS-induced multiple inflammatory cytokines production, carrageenan-induced paw edema, and endotoxin-induced septic mice, was observed. We believe that these findings would provide an idea for the further modification and research of these analogs in the future.
- Zhu, Long-Qing,Fan, Xiao-Hong,Li, Jun-Fang,Chen, Jin-Hong,Liang, Yan,Hu, Xiao-Ling,Ma, Shu-Meng,Hao, Xiang-Yong,Shi, Tao,Wang, Zhen
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supporting information
(2021/05/26)
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- Enantioselective Synthesis of Pyroglutamic Acid Esters from Glycinate via Carbonyl Catalysis
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Direct α-functionalization of NH2-free glycinates with relatively weak electrophiles such as α,β-unsaturated esters still remains a big challenge in organic synthesis. With chiral pyridoxal 5 d as a carbonyl catalyst, direct asymmetric conjugated addition at the α-C of glycinate 1 a with α,β-unsaturated esters 2 has been successfully realized, to produce various chiral pyroglutamic acid esters 4 in 14–96 % yields with 81–97 % ee's after in situ lactamization. The trans and cis diastereomers can be obtained at the same time by chromatography and both of them can be easily converted into chiral 4-substituted pyrrolidin-2-ones such as Alzheimer's drug Rolipram (11) with the same absolute configuration via tert-butyl group removal and subsequent Barton decarboxylation.
- Ma, Jiguo,Zhou, Qinghai,Song, Guanshui,Song, Yongchang,Zhao, Guoqing,Ding, Kuiling,Zhao, Baoguo
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supporting information
p. 10588 - 10592
(2021/04/06)
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- A hydrophilic heterogeneous cobalt catalyst for fluoride-free Hiyama, Suzuki, Heck and Hirao cross-coupling reactions in water
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A hydrophilic heterogeneous cobalt catalyst of chitosan, denoted as mTEG-CS-Co-Schiff-base, has been successfully prepared. This newly synthesized catalyst was characterized by different methods such as XRD, FE-SEM, TEM, TGA, FT-IR, 13C{1H} CP/MAS NMR, XPS and ICP analyses. The catalyst displayed excellent activity for the palladium and fluoride-free Hiyama, Suzuki, Heck and Hirao reactions of various aryl iodides, bromides and chlorides (i.e., the most challenging aryl halides which are cheaper and more widely available than aryl iodides and bromides) in water. The presence of triethylene glycol tags with hydrophilic character on the Co-complex supported on chitosan provides dispersion of the catalyst particles in water, which leads to higher catalytic performance and also facile catalyst recovery by successive extraction. It was reused for at least six successive runs without any discernible decrease in its catalytic activity or any remarkable changes in catalyst structure. The use of water as a green solvent, without requiring any additive or organic solvent, as well as use of a low cost and abundant cobalt catalyst instead of expensive Pd catalysts along with the catalyst recovery and scalability, make this method favorable from environmental and economic points of view for the C-C and C(sp2)-P coupling reactions. Notably, this is the first report on the application of a cobalt catalyst in Hiyama reactions.
- Sobhani, Sara,Hosseini Moghadam, Hadis,Skibsted, J?rgen,Sansano, José Miguel
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p. 1353 - 1365
(2020/03/11)
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- Oxiranyl remote anions from epoxy cinnamates and their application towards the synthesis of α,β-epoxy-γ-butyrolactones
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A series of α,β-epoxy-γ-butyrolactones were synthesized in moderate yields via oxiranyl remote anions derived from epoxy cinnamate esters. The key synthetic step involved deprotonation of the β-position of α,β-epoxy cinnamate derivatives where the generated β-anion was stabilized by remote chelation from an ester group. The substitution reaction of the anion with a variety of ketones, followed by cyclization, readily furnished the desired substituted α,β-epoxy-γ-butyrolactones.
- Sermmai, Patpanat,Ruangsupapichat, Nopporn,Thongpanchang, Tienthong
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supporting information
(2020/11/19)
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- Pd-catalyzed oxidative Heck-type arylation of vinyl ketones, alkenes, and acrylates with Sb-aryl-tetrahydrodibenz[c,f][1,5]azastibocines
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The Pd-catalyzed cross-coupling reactions of Sb-aryl-1,5-azastibocines with alkenes are described. The reactions of azastibocines with alkenes such as vinyl ketones, alkenes, and acrylates in the presence of 10 mol% PdCl2 at 80 °C in DMA under aerobic conditions produced Heck adducts in moderate-to-excellent yields. Single-crystal X-ray and NMR analysis revealed that the aryl donors in this reaction, the Sb-aryl-1,5-azastibocines, are hypervalent compounds that display N–Sb intramolecular non-bonding interaction. These are the first examples of Pd-catalyzed Heck-type arylations using heterocyclic hypervalent organoantimony compounds. Although the reactions proceeded efficiently with the azastibocines, they hardly progressed with trivalent and pentavalent triarylantimony reagents.
- Murata, Yuki,Kakusawa, Naoki,Arakawa, Yukako,Hayashi, Yukako,Morinaga, Shun,Ueda, Masaaki,Hyodo, Tadashi,Matsumura, Mio,Yamaguchi, Kentaro,Kurita, Jyoji,Yasuike, Shuji
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- 1,3-Diphenyldisiloxane Enables Additive-Free Redox Recycling Reactions and Catalysis with Triphenylphosphine
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The recently reported chemoselective reduction of phosphine oxides with 1,3-diphenyldisiloxane (DPDS) has opened up the possibility of additive-free phosphine oxide reductions in catalytic systems. Herein we disclose the use of this new reducing agent as an enabler of phosphorus redox recycling in Wittig, Staudinger, and alcohol substitution reactions. DPDS was successfully utilized in ambient-temperature additive-free redox recycling variants of the Wittig olefination, Appel halogenation, and Staudinger reduction. Triphenylphosphine-promoted catalytic recycling reactions were also facilitated by DPDS. Additive-free triphenylphosphine-promoted catalytic Staudinger reductions could even be performed at ambient temperature due to the rapid nature of phosphinimine reduction, for which we characterized kinetic and thermodynamic parameters. These results demonstrate the utility of DPDS as an excellent reducing agent for the development of phosphorus redox recycling reactions.
- Buonomo, Joseph A.,Cole, Malcolm S.,Eiden, Carter G.,Aldrich, Courtney C.
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p. 3583 - 3594
(2020/09/15)
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- Copper-Photocatalyzed Contra-Thermodynamic Isomerization of Polarized Alkenes
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The contra-thermodynamic isomerization of α- and β-substituted cinnamate derivatives catalyzed by the Cu(OAc)2/rac-BINAP complex under blue light irradiation is reported. The use of an oxazolidinone template, which favored the complexation of the copper catalyst to the substrate, allowed the E → Z isomerization of the catalytically formed chromophore under simple and robust reaction conditions in good to excellent ratios. The mechanism of this process based on the transient formation of a chromophore was also studied.
- Bouillon, Jean-Philippe,Brégent, Thibaud,Poisson, Thomas
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p. 7688 - 7693
(2020/10/09)
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- Mechanochemical Oxidative Heck Coupling of Activated and Unactivated Alkenes: A Chemo-, Regio- and Stereo-Controlled Synthesis of Alkenylbenzenes
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In this work, we present an efficient mechanochemical strategy for chemo-, regio- and stereo-selective oxidative Heck coupling of readily accessible arylboron reagents/heteroaromatics with cyclic and acyclic olefins. Mono- and bis-arylation were achieved without the need of ligands, directing groups or prefunctionalized alkenes, and the reaction chemo-selectivity could be controlled by tuning of the oxidative system. This protocol offers the synthesis of alkenylbenzenes in broad substrate scope, satisfactory yields and excellent selectivity even in the gram scale. (Figure presented.).
- Yu, Jingbo,Shou, Haowen,Yu, Wangyang,Chen, Haodong,Su, Weike
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supporting information
p. 5133 - 5139
(2019/11/11)
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- Preparation method of inactive alkene aryl compound
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The invention discloses a preparation method of an inactive alkene aryl compound. The preparation method comprises steps as follows: arylboronic acid and inactive alkene are taken as raw materials andsubjected to an oxidization Heck reaction with a mechan
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Paragraph 0077; 0078
(2019/06/05)
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- Synthesis and discovery of 18β-glycyrrhetinic acid derivatives inhibiting cancer stem cell properties in ovarian cancer cells
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Despite advances in ovarian cancer treatment, the five-year overall survival rate is less than 30% with the presence of cancer stem cells (CSCs). To develop CSC-targeting therapy, a series of 18β-glycyrrhetinic acid (GA) derivatives containing cinnamamide moiety have been designed, synthesized, and screened for their antiproliferative activity in SKOV3 and OVCAR3 cells. Most of the compounds exhibited stronger antiproliferative activity than GA, and compound 7c was the most active one. Further biological studies showed that compound 7c could induce apoptosis and suppress migration. In addition, compound 7c could not only observably decrease the colony formation and sphere formation ability, but also significantly reduce the CD44+, CD133+, and ALDH+ subpopulation in SKOV3 and OVCAR3 cells. In conclusion, these results indicate that compound 7c is a promising anti-CSC agent for further anti-ovarian cancer studies.
- Li, Xiaojing,Liu, Yihua,Wang, Na,Liu, Yuyu,Wang, Shuai,Wang, Hongmin,Li, Aihua,Ren, Shaoda
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p. 27294 - 27304
(2019/09/12)
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- Recyclable Pd ionic catalyst coated on cordierite monolith for high TOF Heck coupling reaction
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Abstract : Pd 2 + ionic catalyst, Ti 0.97Pd 0.03O 1.97 was coated over cordierite monolith by solution combustion method. The catalyst coated on the cordierite is nano-crystalline as seen from XRD studies. Coated catalyst was used for Heck coupling reactions with different substrates of aryl halides and olefins. Thus handling nano-crystalline catalyst powder is avoided by fixing it on a solid catalyst cartridge. Heck coupled products were characterized using 1H NMR, 13C NMR, Mass and FTIR spectroscopy. This catalyst showed high selectivity towards Heck coupling reaction. Turnover frequencies (TOF) for each of the reactions were found to be very high. The catalyst was recycled up to 7 times with total TOF 3017 h - 1, which is found to be a new green technique in the Heck coupling reaction. Graphical abstract: Ti 0.97Pd 0.03O 1.97 catalyst is coated on cordierite monolith honeycomb (HC) by solution combustion method and it is used in the Heck coupling reaction. Reactions are done in a specially designed flask. Catalyst is recycled for 7 times. The total turnover frequency (TOF) after 7 cycles was 3017 h - 1. [Figure not available: see fulltext.].
- Bhat, Shrikanth K,Prasad, Jagadeesh D,Hegde
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- Phosphetane oxides as redox cycling catalysts in the catalytic wittig reaction at room temperature
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Recently, phosphorus redox cycling has gained significant importance for a number of transformations originally requiring the use of stoichiometric amounts of phosphorus reagents. While these methodologies have several benefits, high catalyst loadings (≥10 mol percent) and harsh reaction conditions (T ≥ 100 °C) often limit their versatility and applicability. Herein, we report differently substituted phosphetane oxides as efficient catalysts for the catalytic Wittig reaction. The phosphetane scaffold is easy to modify, and a number of catalysts can be obtained in a simple two-step synthesis. The activity in the Wittig reaction significantly surpasses previously reported phospholane-based catalysts and the reaction can be conducted with catalyst loadings as low as 1.0 mol percent even at room temperature. Furthermore, a Br?nsted acid additive is no longer required to achieve high yields at these mild conditions. A methyl-substituted phosphetane oxide was employed to synthesize 25 different alkenes with yields of up to 97percent. The methodology has a good functional group tolerance and the reaction can be performed starting with alkyl chlorides, bromides, or iodides. Additionally, it was possible to use poly(methylhydrosiloxane) as the terminal reductant in the catalytic Wittig reaction employing 2-MeTHF as a renewable solvent. The intermediates of the Wittig reaction were analyzed by 31P NMR spectroscopy, and in situ NMR experiments confirmed phosphane oxide as the resting state of the catalyst. Further kinetic investigations revealed a striking influence of the base on the rate of phosphane oxide reduction.
- Longwitz, Lars,Spannenberg, Anke,Werner, Thomas
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p. 9237 - 9244
(2019/10/08)
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- Rhodium(III)-catalyzed β-arylation and- alkenylation of α-trifluoromethylacrylic acid
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The β-arylation and - alkenylation of trifluoromethylacrylic acid with arylboronic acids and alkenes proceed smoothly under rhodium(III) catalysis. The procedures provide useful synthetic routes from readily available building brocks to β-aryl-α-trifluoromethylpropanoic acid and 5, 5, 5-trifluoro-1, 3-butadiene derivatives. Some of the obtained butadienes exhibit strong fluorescence in the solid state.
- Yoshimoto, Risa,Usuki, Yoshinosuke,Satoh, Tetsuya
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p. 461 - 464
(2019/06/03)
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- Synthesis and biological evaluation of celastrol derivatives as anti-ovarian cancer stem cell agents
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Ovarian cancer is associated with a high percentage of recurrence of tumors and resistance to chemotherapy. Cancer stem cells (CSCs) are responsible for cancer progression, tumor recurrence, metastasis, and chemoresistance. Thus, developing CSC-targeting therapy is an urgent need in cancer research and clinical application. In an attempt to achieve potent and selective anti-CSC agents, a series of celastrol derivatives with cinnamamide chains were synthesized and evaluated for their anti-ovarian cancer activities. Most of the compounds exhibited stronger antiproliferative activity than celastrol, and celastrol derivative 7g with a 3,4,5-trimethoxycinnamamide side chain was found to be the most potent antiproliferative agent against ovarian cancer cells with an IC50 value of 0.6 μM. Additionally, compound 7g significantly inhibited the colony formation ability and reduced the number of tumor spheres. Furthermore, compound 7g decreased the percentage of CD44+, CD133+ and ALDH+ cells. Thus, compound 7g is a promising anti-CSC agent and could serve as a candidate for the development of new anti-ovarian cancer drugs.
- Li, Xiaojing,Ding, Jie,Li, Ning,Liu, Wenxia,Ding,Zheng, Huijuan,Ning, Yanyan,Wang, Hongmin,Liu, Renmin,Ren, Shaoda
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p. 667 - 679
(2019/07/05)
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- Polystyrene bis[N-(2-pyridyl) sulfonamide] palladium(II): Synthesis, characterization as a catalyst for coupling reactions
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The [N-(2-pyridyl)] para-styrene sulfonamide (PSS) was prepared as a monomer, from the reaction of para-styrene sulfonyl chloride and 2-amino pyridine in the presence of potassium hydroxide solution 0.5?M as a base, and CH3Cl. Polystyrene [N-(2-pyridyl) sulfonamide] (PPSS) was synthesized from the polymerization of [N-(2-pyridyl)] para-styrene sulfonamide (PSS). The Polystyrene bis [N-(2-pyridyl) sulfonamide] palladium (II) as a polymer- supporting palladium complex was also prepared from the reaction of PdCl2 (CH3CN)2 with PPSS in the presence of KOH 0.5?M. Polystyrene bis [N-(2-pyridyl) sulfonamide] palladium (II) is produced as a novel heterogeneous catalyst for coupling reactions for C-C bond formation. This method includes higher yield and has an easier work-up procedure. The structures of the monomer, polymer and its Pd complex were confirmed by using FT-IR and 1H-NMR spectroscopy. Elemental analysis of Pd by inductively coupled plasma (ICP) technique and hot filtration test showed loading of the metal into solution from the catalyst The heterogeneous catalyst was recycled without any loss in its properties.
- Shafieyoon, Parvaneh,Mehdipour, Ebrahim,Tavakol, Hosein
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p. 324 - 328
(2018/01/04)
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- Magnetic dendritic polymer nanocomposites as supports for palladium: A highly efficient and reusable catalyst for Mizoroki-Heck and Suzuki-Miyaura coupling reactions
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A novel catalyst Fe3O4@SiO2-Dendrimer-Pd based on palladium immobilized on magnetic dendritic polymer nanocomposites was successfully synthesized and characterized by FT-IR, EA, XRD, TEM, EDX, VSM and XPS. This nanocatalyst showed excellent catalytic activity for solvent-free Mizoroki-Heck reaction and Suzuki-Miyaura reaction in EtOH/H2O at a palladium loading of only 0.009 mol%. Moreover, the Fe3O4@SiO2-Dendrimer-Pd catalyst could be conveniently recovered by an external magnet and used consecutively five times with excellent yields. The remarkable catalytic performances and convenient magnetic separability of the Fe3O4@SiO2-Dendrimer-Pd catalyst make it promising for practical application.
- Ma, Rong,Yang, Pengbo,Bian, Fengling
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p. 4748 - 4756
(2018/03/21)
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- Synthesis and structural characterization for novel mixed-donor ligand palladium (II) based on graphene and oxime: its application as a highly stable and efficient recyclable catalyst
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In this article, the palladium (II) mixed-ligand complex synthesized with reduced graphene oxides containing tetraethoxysilane and menthone oxime was used as an efficient solid catalyst for the Heck coupling reaction. To maintain stability and catalytic activity in the C–C bond reaction, graphene was considered due to the available surface as the solid support. Then, the structure of new heterogeneous catalyst was investigated by FT-IR, UV–Vis DRS, FE-SEM, EDX, AFM, XRD, ICP-OES, Raman, and TGA. The newly synthesized nanocatalyst have beneficial properties, including product’s easy separation, the shorter time to react, purity products (yield 79–99%), and easier work-up procedure. Furthermore, the catalyst was reused six times without significant degradation in catalytic activity and performance.
- Ashiri, Samira,Mehdipour, Ebrahim
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p. 2383 - 2393
(2018/08/28)
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- Preparation of a novel palladium catalytic hydrogel based on graphene oxide/chitosan NPs and cellulose nanowhiskers
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The present paper focuses on the synthesis of a novel hydrogel support by combining polysaccharides (chitosan NPs and dialdehyde cellulose nanowhiskers) and graphene oxide nanosheets to obtain a biocompatible material for catalytic applications. The hydrogel was synthesized via green chemistry processes and used as a support to prepare Pd nanoparticles. Finally, the hydrogel@Pd NPs was employed as the catalyst in the Mizoroki-Heck reaction to generate new C-C bonds. SEM analysis indicated that the hydrogel has macroporous morphology, which is in good correlation with its high crosslinking degree. The as-synthesized nanocomposite hydrogel exhibits beneficial properties such as ease of separation and excellent recyclability for at least six cycles without considerable loss in its activity. The yields of the products range from 81% to 98%. Additionally, this study provides the possibility to perform the Mizoroki-Heck reaction with aryl chloride in the presence of the as-prepared catalyst.
- Ashiri, Samira,Mehdipour, Ebrahim
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supporting information
p. 32877 - 32885
(2018/10/15)
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- Piperidine-appended imidazolium ionic liquid as task-specific basic-IL for Suzuki and Heck reactions and for tandem Wittig-Suzuki, Wittig-Heck, Horner-Emmons-Suzuki, and Horner-Emmons-Heck protocols
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Facile, high yielding, one-pot methods for the synthesis of a library of diversely substituted bi-aryls, diarylethenes, and aryl-enoates, via Suzuki and Heck reactions, and by sequential Wittig-Suzuki, Wittig-Heck, Horner-Emmons-Suzuki, and Horner-Emmons-Heck reactions are reported. The reactions employ piperidine-appended imidazolium ionic liquid [PAIM][NTf2] as a task-specific basic-IL, butyl-methyl-imidazolium ionic liquid [BMIM][X] (X?=?PF6, BF4) as solvent, and catalytic amounts of Pd(OAc)2 with no other additives. Wittig and Horner-Emmons reactions are effected by reacting substituted benzaldehydes with 4-bromobenzyl-PPh3 (or bromomethyl-PPh3) phosphonium salts, or diethylphosphonate with bromobenzaldehydes respectively, to form the corresponding ethenes. Subsequent cross-coupling reactions are accomplished by addition of aryl-boronic acid or phenyl-ethenes along with Pd(OAc)2 to bring about the aforementioned hyphenated transformations. The feasibility to perform double-olefination via Wittig and Horner-Emmons reactions with dialdehydes to form highly conjugated bis-styryl and bis-enoate compounds is also shown. The [BMIM][X] solvent is recycled and reused.
- Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
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p. 150 - 161
(2017/06/30)
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- Control of Chemo-, Regio-, and Enantioselectivity in Copper Hydride Reductions of Morita-Baylis-Hillman Adducts
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Nonracemically ligated copper hydride can be used to effect tandem SN2′/1,2-reductions of racemic Morita-Baylis-Hillman (MBH) acetates to access enantioenriched chiral allylic alcohols with defined olefin geometry. MBH esters, including those w
- Linstadt, Roscoe T. H.,Peterson, Carl. A.,Jette, Carina I.,Boskovic, Zarko V.,Lipshutz, Bruce H.
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supporting information
p. 328 - 331
(2017/04/21)
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- An ionic liquid catalyzed probase method for one-pot synthesis of α,β-unsaturated esters from esters and aldehydes under mild conditions
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A one-pot synthesis of α,β-unsaturated esters from unactivated esters and aldehydes using strong bases, such as sodium alkoxide and potassium tert-butoxide, was reported. However, the ionic liquid (IL) catalyzed probase method for producing α,β-unsaturated esters was not reported until now. In this work, a series of ILs with fluoride anions were firstly prepared and used as catalysts in combination with the probase N,O-bis(trimethylsilyl) acetamide (BSA) for the α,β-unsaturated esters synthesis. This process could also be promoted through the introduction of another IL with Lewis acid sites. The yield and selectivity of the product could reach up to 84.2% and 95.0%, respectively, when [Bmim]F was used in combination with [Bmim]Cl/AlCl3 (the molar fraction of AlCl3 is 0.67). The mechanism investigation through GC-MS indicates that BSA would convert into onium amide, which acted as a strong base for α-H abstraction, with the catalysis of [Bmim]F. Meanwhile, [Bmim]Cl/AlCl3 played an important role in the condensation step between enolates and aldehydes. On the basis of mechanism insights, kinetic and thermodynamic studies were also carried out for a better understanding of this new route.
- Wang, Gang,Xu, Yiming,Zhang, Suojiang,Li, Zengxi,Li, Chunshan
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p. 4838 - 4848
(2017/10/23)
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- Tetrakis [N-(2-pyridyl) sulfonamide] di palladium: synthesize, X-ray diffraction, antibacterial properties and as a novel binuclear Pd-complex for coupling reactions
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The N-(2-pyridyl) 4-toluene sulfonamide as a free ligand (PTS) was prepared from the reaction of 2-amino pyridine and 4-toluenesulfonyl chloride in the presence of potassium hydroxide solution 1?M as a base and THF was used as a solvent. The complex tetrakis [N-(2-pyridyl) sulfonamide] di palladium (1) (Pd2L4) was also prepared from the reaction of PdCl2(CH3CN)2 using (PTS) in the presence of NaOH 0.5?M and its application in Heck and Suzuki reactions. This complex consists of a binuclear unit consisting of four ligands linked to two palladium atoms via the nitrogen of pyridines ring and the nitrogen of sulfonamides. These compounds were confirmed by FT-IR and 1H NMR spectroscopy. Moreover, the structure of the complex was studied by single-crystal X-ray diffraction method. The green crystal of Pd2L4 [L?=?N-(2-pyridyl) sulfonamide](1) was found to crystallize in the monoclinic space group C2/c with a?=?18.2013(19), b?=?19.7544(16), c?=?17.2898(19) ?, β?=?120.179(8) °; V?=?5374.0(9) ?3; Z =?4; the final R1?=?0.0894, wR2?=?0.1754 (or 5867 observed reflections and 318 variables). The Pd–Pd distance is 2.567(2) ?. In addition, PTS and Pd2L4 presented different antibacterial behaviors. The free ligand was active against Staphylococcus aureus and Escherichia coli, but the complex was inactive against them.
- Mehdipour, Ebrahim,Shafieyoon, Parvaneh,Salahvarzi, Maryam,Amani, Vahid
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p. 1575 - 1582
(2017/06/06)
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- A New Mode of Operation of Pd-NHC Systems Studied in a Catalytic Mizoroki-Heck Reaction
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Metal complexes bearing N-heterocyclic carbene (NHC) ligands are typically considered the system of choice for homogeneous catalysis with well-defined molecular active species due to their stable metal-ligand framework. A detailed study involving 19 different Pd-NHC complexes with imidazolium, benzimidazolium, and triazolium ligands has been carried out in the present work and revealed a new mode of operation of metal-NHC systems. The catalytic activity of the studied Pd-NHC systems is predominantly determined by the cleavage of the metal-NHC bond, while the catalyst performance is strongly affected by the stabilization of in situ formed metal clusters. In the present study, the formation of Pd nanoparticles was observed from a broad range of metal complexes with NHC ligands under standard Mizoroki-Heck reaction conditions. A mechanistic analysis revealed two different pathways to connect Pd-NHC complexes to "cocktail"-type catalysis: (i) reductive elimination from a Pd(II) intermediate and the release of NHC-containing byproducts and (ii) dissociation of NHC ligands from Pd intermediates. Metal-NHC systems are ubiquitously applied in modern organic synthesis and catalysis, while the new mode of operation revealed in the present study guides catalyst design and opens a variety of novel opportunities. As shown by experimental studies and theoretical calculations, metal clusters and nanoparticles can be readily formed from M-NHC complexes after formation of new M-C or M-H bonds followed by C-NHC or H-NHC coupling. Thus, a combination of a classical molecular mode of operation and a novel cocktail-type mode of operation, described in the present study, may be anticipated as an intrinsic feature of M-NHC catalytic systems.
- Astakhov, Alexander V.,Khazipov, Oleg V.,Chernenko, Andrey Yu.,Pasyukov, Dmitry V.,Kashin, Alexey S.,Gordeev, Evgeniy G.,Khrustalev, Victor N.,Chernyshev, Victor M.,Ananikov, Valentine P.
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supporting information
p. 1981 - 1992
(2017/06/14)
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- Suzuki and Heck cross-coupling reactions using ferromagnetic nanoparticle-supported palladium complex as an efficient and recyclable heterogeneous nanocatalyst in sodium dodecylsulfate micelles
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A novel heterogeneous Pd catalyst was synthesized by anchoring Pd(II) onto 4′-(4-hydroxyphenyl)-2,2′:6′,2″-terpyridine-coated Fe3O4 (FMNPs@TPy-Pd). This catalyst has been demonstrated for the first time as a recoverable and reusable heterogeneous nanocatalyst in Suzuki and Heck cross-coupling reactions. The catalyst is very easy to handle and is environmentally safe and economical. FMNPs@TPy-Pd was characterized using transmission and scanning electron microscopies, X-ray diffraction, and Fourier transform infrared and energy-dispersive X-ray spectroscopies.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Meibodi, Farhat Sadat
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- Efficient and selective palladium-catalyzed direct oxidative esterification of benzylic alcohols under aerobic conditions
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A highly efficient palladium-catalyzed approach for the direct oxidative esterification of benzylic alcohols with methanol and long-chain aliphatic alcohols under mild conditions has been achieved. This practical catalyst system exhibits a broad substrate scope and good functional group tolerance. Catalytic amount of Bi(OTf)3 is used as co-catalyst to improve the activity and selectivity of the reactions. A variety of esters are obtained in yields of 43–96%.
- Hu, Yongke,Li, Bindong
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p. 7301 - 7307
(2017/11/29)
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- Palladium-Schiff Base Complex Immobilized Covalently on Magnetic Nanoparticles as an Efficient and Recyclable Catalyst for Heck and Suzuki Cross-Coupling Reactions
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A new palladium-Schiff base complex immobilized covalently on magnetic nanoparticles (Pd-imino-Py-γ-Fe2O3) was synthesized via the reaction of chloro-functionalized γ-Fe2O3 with iminopyridine followed by the reaction with palladium acetate. Characterization of Pd-imino-Py-γ-Fe2O3 was carried out by various techniques such as XRD, SEM, TEM, FT-IR, TGA, ICP, XPS, VSM and elemental analysis. Pd-imino-Py-γ-Fe2O3 was successfully applied as a magnetically recyclable heterogeneous catalyst in Heck and Suzuki cross-coupling reactions of various aryl halides (iodide, bromides and chlorides as challenging substrates) with olefins and phenylboronic acid, respectively. The synthesized catalyst was separated easily by using an external magnet and recycled eight runs without appreciable loss of its catalytic activity and leaching of the significant quantity of Pd. Graphical Abstract: [Figure not available: see fulltext.]
- Sobhani, Sara,Falatooni, Zahra Mesbah,Asadi, Solmaz,Honarmand, Moones
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p. 255 - 268
(2016/02/23)
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- Magnetic iron oxide nanoparticles–N-heterocyclic carbene–palladium(II): a new, efficient and robust recyclable catalyst for Mizoroki–Heck and Suzuki–Miyaura coupling reactions
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A new and efficient nanoparticle–N-heterocyclic carbene–palladium complex was synthesized and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, transmission electron microscopy, elemental analysis, inductively coupled plasma analysis and vibrating sample magnetometry. This catalytic system was found to be a highly active catalyst in the Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions. These reactions were best performed in dimethylformamide and water, respectively, in the presence of only 0.054 mol% of palladium under mild conditions. Moreover, the catalyst could be recovered easily and reused at least ten times without any considerable loss of its catalytic activity. Copyright
- Hajipour, Abdol R.,Tadayoni, Nayereh S.,Khorsandi, Zahra
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p. 590 - 595
(2016/07/16)
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- Synthesis and characterization of bifunctional lipophilic and basic mesoporous organosilica supported palladium nanoparticles as an efficient and ecofriendly nanocomposite in aqueous Heck reaction
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In the present study, a highly ordered mesoporous organosilica nanocomposite having modified pore channels with both lipophilic and basic units, SBA-R/Im-NH2, was synthesized through surfactant-templated sol-gel methodology and post modification process. The nanocomposite with ionic liquid properties was used as a potential host for supporting palladium nanoparticles. The structure and composition of the target nanocomposite, SBA-R/Im-NH2·Pd, were supported by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), elemental analysis (CHNS), energy dispersive X-ray (EDX) and Brunauer-Emmett-Teller (BET) measurements. The efficiency of this porous inorganic-organic hybrid nanocomposite as a powerful catalyst in one of the most important carbon-carbon bond-forming process, the Heck coupling reaction of aryl halides with olefins, in aqueous media was also examined. This method has the advantages of high yields, cleaner reactions, simple methodology, short reaction times, easy workup, and greener conditions. In addition, the nanocatalyst can be easily separated from the reaction mixture and reused several times without significant decrease in activity and promises economic as well as environmental benefits.
- Jafari Nasab, Mina,Kiasat, Ali Reza
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p. 81614 - 81621
(2016/09/09)
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- Regioselective Coupling Reactions of Coumarins with Aldehydes or Di-tert-butyl Peroxide (DTBP) through a C(sp2)-H Functionalization Process
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Coumarin derivatives are highly valuable compounds in drug discovery. Herein, we have developed two new coupling reactions that involve coumarins and either aldehydes or di-tert-butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp2)-H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These coupling reactions will enrich current coumarin chemistry.
- Zhao, Wannian,Xu, Lei,Ding, Yingcai,Niu, Ben,Xie, Ping,Bian, Zhaogang,Zhang, Denghong,Zhou, Aihua
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p. 325 - 330
(2016/02/14)
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- A magnetic porous chitosan-based palladium catalyst: A green, highly efficient and reusable catalyst for Mizoroki-Heck reaction in aqueous media
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A novel, biodegradable and environmentally benign magnetic porous chitosan-thienyl imine palladium(ii) complex, MPCS-TI/Pd, was prepared and characterized by FT-IR, SEM, TEM, EDX, XRD, BET, VSM and TG-DTA analysis. This complex, with high surface areas and low catalyst loading, was found to be a highly active and robust heterogeneous catalyst for the Mizoroki-Heck reaction of aryl bromides and chlorides with various terminal olefins in aqueous media in good to excellent yields. The catalyst was easily separated using an external magnet and the recovered catalyst was reused for seven cycles without significant loss of catalytic activity.
- Movassagh, Barahman,Rezaei, Nasrin
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supporting information
p. 7988 - 7997
(2015/10/12)
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- Palladium supported on poly (ionic liquid) entrapped magnetic nanoparticles as a highly efficient and reusable catalyst for the solvent-free Heck reaction
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A novel palladium catalyst supported on poly (1-aminoethyl-3-vinylimidazolium bromide) entrapped magnetic nanoparticles (Pd/Fe3O4@PIL-NH2) was prepared. The catalyst was characterized by TEM, FT-IR, VSM, XRD, and XPS. The Pd loading on the catalyst was 0.23 wt % as measured by AAS. The catalyst showed excellent activity for the solvent-free Heck reaction. In addition, this novel Pd catalyst could be simply recovered with an external magnet and run five times with excellent yields achieved.
- Liu, Wendong,Wang, Dongfang,Duan, Yajing,Zhang, Yahui,Bian, Fengling
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supporting information
p. 1784 - 1789
(2015/03/30)
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- Pd-isatin Schiff base complex immobilized on γ-Fe2O3 as a magnetically recyclable catalyst for the Heck and Suzuki cross-coupling reactions
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A Pd-isatin Schiff base complex immobilized on γ-Fe2O3 (Pd-isatin Schiff base-γ-Fe2O3) was synthesized and characterized by Fourier transform infrared, scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, thermogravimetric gravimetric analysis, inductively-coupled plasma, X-ray photoelectron spectroscopy, and elemental analysis. It was used as a magnetically reusable Pd catalyst for the Heck and Suzuki cross-coupling reactions.
- Sobhani, Sara,Zarifi, Farzaneh
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p. 555 - 563
(2015/09/28)
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- Silica-acetylacetone-supported palladium nanoparticles as an efficient and reusable catalyst in the Heck-Mizoroki C-C cross-coupling reaction
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The preparation of palladium nanoparticles supported on acetylacetone-modified silica gel and their catalytic application for Heck olefination of aryl halides were investigated. The catalyst was characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and transmission and scanning electron microscopies. The supported palladium nanoparticles are demonstrated to be a highly active and reusable catalyst for the Heck reaction. Several reaction parameters, including type and amount of solvent and base, were evaluated. The heterogeneity of the catalytic system was investigated with results indicating that there is a slight palladium leaching into the reaction solution under the applied reaction conditions. Despite this metal leaching, the catalyst can be reused nine times without significant loss of catalytic activity.
- Hajipour, Abdolreza,Shirdashtzade, Zohre,Azizi, Ghobad
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p. 143 - 146
(2015/03/30)
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- Carboncarbon bond forming reactions: Application of covalently anchored 2,4,6-triallyloxy-1,3,5-triazine (TAT) Pd(II) complex over modified surface of SBA-15 to Heck, Suzuki, Sonogashira and Hiyama cross coupling reactions
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A highly active SBA-15-TAT-Pd(II) catalyst was synthesized from organofunctionalized SBA-15 and 2,4,6-triallyloxy-1,3,5-triazine. The catalyst was employed in carrying out Heck, "copper-free" Sonogashira, Suzuki and Hiyama cross coupling reactions. Under the optimized conditions the catalyst displays excellent catalytic activity in delivering the desired products in good to excellent yields. The catalytic system exhibited superior activity regarding the time taken for the completion of reaction, isolation, Pd loading (0.62 mmol%) and yields of products as compared to the earlier reported heterogeneous SBA-15 anchored Pd catalysts. The catalyst could be recycled and reused for five times without any appreciable loss of catalytic activity.
- Singh, Chandani,Jawade, Kiran,Sharma, Priti,Singh, Anand P.,Kumar, Pradeep
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- Synthesis, characterization, photophysical properties, and catalytic activity of an SCS bis(N-heterocyclic thione) (SCS-NHT) Pd pincer complex
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Treatment of 1,3-bis(3′-butylimidazolyl-1′-yl)benzene diiodide with elemental sulfur in the presence of a base produced a bis(N-heterocyclic thione) (NHT) pincer ligand precursor. Its reaction with PdCl2(CH3CN)2 produced chloro[1,3-bis(3′-butylimidazole-2′-thione-κ-S)benzene-κ-C]palladium(ii), a 6,6-fused ring SCS-NHT palladium pincer complex. This air stable compound is, to our knowledge, the first SCS pincer complex that utilizes N-heterocyclic thione (NHT) donor groups. The molecular structures of the ligand precursor and the palladium complex were determined by X-ray crystallography and computational studies provided insight into the interconversion between its rac and meso conformations. The photophysical properties of the complex were established, and its catalytic activity in Suzuki, Heck, and Sonogashira cross-coupling reactions was evaluated.
- Tyson, Ginger E.,Tokmic, Kenan,Oian, Casey S.,Rabinovich, Daniel,Valle, Henry U.,Hollis, T. Keith,Kelly, John T.,Cuellar, Kristina A.,McNamara, Louis E.,Hammer, Nathan I.,Webster, Charles Edwin,Oliver, Allen G.,Zhang, Min
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supporting information
p. 14475 - 14482
(2015/08/24)
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- A practical, chemoselective approach to O-methylation of carboxylic acids with dimethyl malonate
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A practical and chemoselective method is described for the O-methylation of carboxylic acids. Dimethyl malonate, a low toxic and commercially available compound was found to be an effective methylating reagent for a variety of carboxylic acids affording methyl ester products in good to high yields and with excellent chemoselectivity, without the use of strong bases as additives. A mechanism involving the utilization of potassium bromide is tentatively proposed.
- Mao, Jincheng,Liu, Defu,Li, Yongming,Zhao, Jinzhou,Rong, Guangwei,Yan, Hong,Zhang, Guoqi
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p. 9067 - 9072
(2015/11/09)
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- Ligand-Controlled Palladium-Catalyzed Alkoxycarbonylation of Allenes: Regioselective Synthesis of α,β- and β,γ-Unsaturated Esters
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The palladium-catalyzed regioselective alkoxycarbonylation of allenes with aliphatic alcohols allows to produce synthetically useful α,β- and β,γ-unsaturated esters in good yields. Efficient selectivity control is achieved in the presence of appropriate ligands. Using Xantphos as the ligand, β,γ-unsaturated esters are produced selectively in good yields. In contrast, the corresponding α,β-unsaturated esters are obtained with high regioselectivity in the presence of PPh2Py as the ligand. Preliminary mechanistic studies revealed that these two catalytic processes proceed by different reaction pathways. In addition, this novel protocol was successfully applied to convert an industrially available bulk chemical, 1,2-butadiene, into dimethyl adipate, which is a valuable feedstock for polymer and plasticizer syntheses, with high yield and TON (turnover number).
- Liu, Jie,Liu, Qiang,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 8556 - 8563
(2015/07/15)
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- A water-soluble palladium-salen catalyst modified by pyridinium salt showing higher reactivity and recoverability for Heck coupling reaction
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A novel and water-soluble palladium-salen catalyst modified by pyridinium salt was synthesized and characterized by NMR, HRMS, FT-IR, ICP, elemental analysis and UV-vis spectroscopy. The catalyst can efficiently catalyze the Heck reaction between aryl halides and olefins. The reaction using 0.5 mol% catalyst can achieve 98.3% conversion with 99% selectivity. The catalytic activity of catalyst modified by pyridinium salt is higher than that of un-modified one. Furthermore, the catalyst can be easily separated from reaction system by water wash and subsequently recycled for six runs without significant loss of activity and selectivity.
- Yuan, Linghua,Xu, Yun,Hu, Xingbang,Yang, Guoqiang,Wu, Youting
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- A water-soluble palladium-salen catalyst modified by pyridinium salt showing higher reactivity and recoverability for Heck coupling reaction
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A novel and water-soluble palladium-salen catalyst modified by pyridinium salt was synthesized and characterized by NMR, HRMS, FT-IR, ICP, elemental analysis and UVvis spectroscopy. The catalyst can efficiently catalyze the Heck reaction between aryl halides and olefins. The reaction using 0.5 mol% cat-alyst can achieve 98.3% conversion with 99% selectivity. The catalytic activity of catalyst modified bypyridinium salt is higher than that of un-modified one. Furthermore, the catalyst can be easily separatedfrom reaction system by water wash and subsequently recycled for six runs without significant loss ofactivity and selectivity.
- Yuan, Linghua,Xu, Yun,Hu, Xingbang,Yang, Guoqiang,Wu, Youting
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- Investigation of sol-gel supported palladium catalysts for Heck coupling reactions in o/w-microemulsions
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Sol-gel supported palladium catalysts are investigated for the Heck coupling reaction between styrene and iodo-/bromobenzene to trans-stilbenes in o/w-microemulsions as alternative reaction medium. High conversions and selectivities are obtained with these catalysts and they show better catalytic performance than their commercial analogs Pd@SiO2 or Pd/C. The influence of the catalyst structure on the activity is investigated in detail showing mass transport limitations that can be optimized by the palladium loading. The catalyst is recyclable >6 times with negligible palladium leaching into the solution. Because of the good recyclability under retention of activity and selectivity, the influence of transport limitations is suppressed and the total catalyst efficiency is increased to more than 2.
- Volovych,Kasaka,Schwarze,Nairoukh,Blum,Fanun,Avnir,Schom?cker
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p. 210 - 221
(2014/07/22)
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- Acetamidine-palladium complex immobilized on γ-Fe2O3 nanoparticles: A novel magnetically separable catalyst for Heck and Suzuki coupling reactions
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A new palladium-Schiff base complex immobilized on iron oxide nanoparticles (γ-Fe2O3-acetamidine-Pd) was synthesized via the reaction of amino-functionalized γ-Fe2O3 with acetamide followed by the reaction with palladium acetate. Characterization of γ-Fe2O3-acetamidine-Pd was carried out by various techniques such as XRD, SEM, HRTEM, FT-IR, TGA, ICP, XPS and elemental analysis. γ-Fe2O3-acetamidine-Pd was successfully applied as a magnetically recyclable catalyst in Heck and Suzuki coupling reactions. By these protocols, aryl halides were coupled with olefins (Heck coupling reaction) and phenylboronic acid (Suzuki coupling reaction) to afford the corresponding products in moderate to high yields. Furthermore, the synthesized catalyst was separated easily by using an external magnet and recycled for five runs without appreciable loss of its catalytic activity. This journal is
- Sobhani, Sara,Ghasemzadeh, Maryam Sadat,Honarmand, Moones,Zarifi, Farzaneh
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p. 44166 - 44175
(2014/12/10)
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- Synthesis of chiral α-benzyl-β2-hydroxy carboxylic acids through iridium-catalyzed asymmetric hydrogenation of α- oxymethylcinnamic acids
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An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed by using chiral spiro phosphine-oxazoline/iridium complexes as catalysts to prepare β2-hydroxycarboxylic acids with high reactivity (TON up to 2000) and excellent enantioselectivity (up to 99.5% ee). By using this highly efficient asymmetric hydrogenation as a key step, a concise total synthesis of natural product homoisoflavone (S)-(+)-4 was accomplished. An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed to prepare β2-hydroxycarboxylic acids with high reactivity (TON up to 2000) and excellent enantioselectivity (up to 99.5% ee), which was applied to a concise total synthesis of a natural product homoisoflavone. Copyright
- Li, Ze-Yu,Song, Song,Zhu, Shou-Fei,Guo, Na,Wang, Li-Xin,Zhou, Qi-Lin
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supporting information
p. 783 - 787
(2014/10/16)
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- Selective preparation of functionalized dienes from allylic phosphonium salts through the wittig reaction
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A convenient and general method for the synthesis of stereochemically defined dienes from allylic phosphonium salts under simple conditions is described. Selective preparation of trisubstituted dienes was performed with good-to-excellent yields in mild ba
- Sa, Marcus M.,Meier, Lidiane
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p. 384 - 391
(2013/09/23)
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- The [RPPhPd as a catalyst precursor for the heck cross-coupling reaction by in situ formation of stabilized Pd(0) nanoparticles
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Pd(II) anionic, square planar complexes of the type [RPPhPdl, where X = Cl, Br, have been applied for the first time as a catalyst precursor for the Heck reaction carried out in DMF at 140 °C. The highest yield was obtained for the most reducible ones, [MePPhPdrl, in DMF in the presence of NaHCOas a base. It was found that during the reaction, phosphonium halide stabilized Pd(0) nanoparticles of about 10 nm, which have been formed in situ from the palladium(II) precursor and Pd(0) colloidal nanoparticles acts as the reservoir for Pd(II) species via activation of the metal surface through the oxidative addition of aryl halides. Georg Thieme Verlag Stuttgart New York.
- Hajipour, Abdol Reza,Azizi, Ghobad
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supporting information
p. 254 - 258
(2013/03/13)
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- Iron-catalyzed cross-coupling reaction: Recyclable heterogeneous iron catalyst for selective olefination of aryl iodides in poly(ethylene glycol) medium
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An environmentally friendly iron-based catalyst supported on acac-functionalized silica was successfully prepared and evaluated as a heterogeneous catalyst for Mizoroki-Heck reaction of aryl iodides and olefins. Our catalytic system showed good activities that were comparable to that of palladium catalysts. The catalyst was simply recovered from the reaction mixture and recycled five times. Furthermore, the reaction was carried out in poly(ethylene glycol) as a green solvent. Interestingly, using this catalyst, aryl iodides were selectively olefinated in the presence of aryl bromides.
- Hajipour, Abdol Reza,Azizi, Ghobad
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p. 1030 - 1034
(2013/07/26)
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- Pd(diimine)Cl2 embedded heterometallic compounds with porous structures as efficient heterogeneous catalysts
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Four porous heterometallic coordination polymers were synthesized via a metalloligand strategy. All of them contain the [Pd(diimine)Cl2] moiety, which has good catalytic activity, and present remarkable versatility for catalysing Suzuki-Miyaura
- Huang, Sheng-Li,Jia, Ai-Quan,Jin, Guo-Xin
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p. 2403 - 2405
(2013/04/10)
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- A robust first-pass protocol for the heck-mizoroki reaction
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The Heck-Mizoroki (HM) reaction is one of the most widely used C-C bond-forming methods of contemporary synthesis. Notwithstanding this, these reactions frequently require significant optimization before efficient transformations can be obtained. We describe here the results of a study that aimed to establish a generic experimental protocol for HM reactions which enables acceptable yields from first-pass experiments. The methodology utilizes readily available stable catalysts and can be applied to a broad range of coupling partners.
- Murray, Paul M.,Bower, John F,Cox, David K,Galbraith, Ewan K,Parker, Jeremy S,Sweeney, Joseph B.
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p. 397 - 405
(2013/04/24)
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