1204-60-0Relevant articles and documents
A recyclable heterogeneous nanocatalyst of copper-grafted natural asphalt sulfonate (NAS@Cu): Characterization, synthesis and application in the Suzuki-Miyaura coupling reaction
Kohzadi, Homa,Soleiman-Beigi, Mohammad
, p. 12134 - 12142 (2020)
A new and efficient nanocatalyst was identified, synthesized and introduced and its catalytic activity was investigated in the Suzuki coupling reaction. This nanocatalyst can be synthesized by sulfonating natural asphalt as a high-carbon, cost-effective and accessible substrate using high-concentration sulfuric acid. After being neutralized by NaOH, it was transformed into sodium natural asphalt sulfonate (Na-NAS). Ultimately, the nanocatalyst was synthesized through a displacement reaction of sodium natural asphalt sulfonate with copper chloride. The solid derived (NAS@Cu) was identified using Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS), Scanning Electron Microscopy (SEM), N2 sorption isotherms, Inductively Coupled Plasma (ICP), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Atomic Absorption Spectrometry (AAS) and Fourier-transform Infrared spectroscopy (FT-IR). NAS@Cu is a heterogeneous catalyst with advantages such as having a high specific surface area, being environmentally friendly and economically sound and simple purification and separation from the reaction mixture. Moreover, the nano-catalyst was recycled several times without any significant changes in its catalytic properties. This journal is
The Suzuki reaction under solvent-free conditions
Nielsen,Peters,Axelsson
, p. 3501 - 3509 (2000)
The coupling reaction of diverse arylhalogenids with phenylboronic acid under solvent-free conditions has been performed using a palladium catalyst. The order of reactivity was complementary to the normal Suzuki reaction.
Immobilized palladium on modified magnetic nanoparticles and study of its catalytic activity in suzuki-miyaura C-C coupling reaction
Azadi, Gouhar,Ghorbani-Choghamarani, Arash
, p. 360 - 366 (2016)
A new magnetically reusable nanosolid, Fe3O4@PPCA@Pd(0) (PPCA = piperidine-4-carboxylic acid), as a versatile and highly effective catalyst was fabricated and characterized using transmission and scanning electron microscopies, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared and energy-dispersive spectroscopies and vibrating sample magnetometry. This nanosolid shows great catalytic activity for the synthesis of biphenyl compounds in short reaction times and with high yields. The magnetic character of this catalyst allows retrieval and multiple uses without appreciable loss of its catalytic activity. Our system not only solves the basic problems of catalyst separation and recovery, but also the reactions can be performed in green media.
Nitrogen-doped graphdiyne for effective metal deposition and heterogeneous Suzuki-Miyaura coupling catalysis
He, Feng,He, Jingyi,Li, Yongjun,Li, Yuliang,Shen, Han,Xue, Yurui
, (2021)
For heterogeneous catalysts with nitrogen doped carbon materials as supporting substrates, accurate nitrogen (N) species and content is an important factor for promoting the catalytic activity. In this paper, N-doped graphdiyne (NGDY) was prepared from tetraethynylpyrazine (TEP) by bottom-up synthesis method as the support of metal nanoparticles. Specific pyridine nitrogen atoms are introduced in the N-doped carbon material. This unique structure makes it a promising material to support ultrafine metal particles or clusters. Microwave-assisted anchoring of Pd, Pt, Cu, Ni nanoparticles on NGDY generated novel hybrid composites, in which Pd-NGDY has high versatility for Suzuki-Miyaura reaction. DFT calculations revealed a charge transfer from NGDY to Pd NPs, and the free energy distribution showed a downward trend for Suzuki-Miyaura coupling reactions.
Pd(OAc)2@SBA-15/PrEn nanoreactor: A highly active, reusable and selective phosphine-free catalyst for Suzuki-Miyaura cross-coupling reaction in aqueous media
Rostamnia, Sadegh,Xin, Hongchuan
, p. 348 - 352 (2013)
A series of ordered mesoporous organic-inorganic hybrid material was designed by using the amine-functionalized SBA-15 (PdX2@SBA-15/N Y, Y = 1, 2) as solid support for palladium complexes. Among them, the Pd(OAc)2/ethylenediamine complex encapsulated into SBA-15 (Pd(OAc)2@SBA-15/PrEn or Pd(OAc)2@SBA-15/PrNHEtNH 2) exhibits higher activity and selectivity toward Suzuki cross-coupling reaction under aerobic conditions and water solvent mixture. The SBA-15/PrEn supported palladium pre-catalyst could be separated easily from reaction products and used repetitively several times, showing its superiority over homogeneous catalysts for industrial and chemical applications. Copyright
Suzuki-Miyaura cross-coupling reaction catalyzed by a highly stable Pd(P-Phos)Cl2 complex at room temperature under air
Ge, Yicen,Cheng, Yujing,Fu, Haiyan,Zheng, Xueli,Li, Ruixiang,Chen, Hua,Li, Xianjun
, p. 1667 - 1673 (2013)
A new Pd(P-Phos)Cl2 complex was synthesized and characterized by 1H NMR, 13C NMR, 31P NMR, and X-ray single crystal structure determination. The complex proved to be a highly stable and efficient catalyst for substrates with a wide range of functional groups in Suzuki-Miyaura cross-coupling reactions under air at room temperature. Low catalyst loadings were employed and turnover number of up to 49000 was obtained.
Highly efficient copper(0)-catalyzed Suzuki-Miyaura cross-coupling reactions in reusable PEG-400
Mao, Jincheng,Guo, Jun,Fang, Fubing,Ji, Shun-Jun
, p. 3905 - 3911 (2008)
Readily available copper powder with K2CO3 as the base was extremely effective catalyst for Suzuki-Miyaura coupling reaction performed in PEG-400, which afforded almost quantitative coupling products of aryl iodides. Using iodine as additive, coupling products of aryl bromides or chlorides could be obtained with moderate to good yields.
Suzuki coupling reactions catalyzed by Schiff base supported palladium complexes bearing the vitamin B6 cofactor
Neshat, Abdollah,Gholinejad, Mohammad,?zcan, Hafize,Khosravi, Faezeh,Mobarakeh, Ali Mousavizadeh,Zaim, ?mer
, (2021)
Novel Schiff bases were synthesized by condensing aromatic amines with pyridoxal-5’-phosphate and characterized by using FT-IR, 1H NMR, and 13C NMR spectroscopic techniques. The resulting Schiff bases were utilized as bidentate ligands, coordinating via imine nitrogen and phenolate oxygen atoms, to stabilize palladium ions. Aryl substituents on imine nitrogen allowed for fine tuning of the stereoelectronic properties of the Schiff bases. The catalytic activity of the selected palladium complexes was investigated in the Suzuki cross-coupling reaction of a series of aryl halides with boronic acids in H2O/EtOH (1:1). Out of four complexes investigated in the cross-coupling reactions, Pd(L8)2, bearing a methoxy substituent on aryl imine, showed the highest activity at low catalyst loading. The scope of the reaction was also investigated with 26 samples.
Pd(0) complex of fuberidazole modified magnetic nanoparticles: A novel magnetically retrievable high-performance catalyst for Suzuki and Stille C-C coupling reactions
Nouri, Kheirollah,Ghassemzadeh, Mitra,Mohsenzadeh, Farshid,Afsharpour, Maryam
, (2020)
Fuberidazole has been successfully immobilized onto nano-Fe3O4 supported (3-chloropropyl)trimethoxysilane (3-CPTS) leading to a novel functionalized magnetic nanoparticle (FB/MNP). The Pd(0) complex, Pd-FB/MNP, was prepared by grafting Pd (OAc)2 on FB/MNP and subsequent reduction of a synthesized Pd (II) complex using NaBH4. Pd-FB/MNP has been characterized by FT-IR, SEM, TGA, XRD, ICP, EDS, BET and VSM. The Pd(0) complex proved to be an efficient phosphine- and halide-free recyclable heterogeneous catalyst for Suzuki as well as for Stille C-C coupling reactions showing high catalytic activity (up to 98percent). Its catalytic activity in both reactions has been studied in PEG-400 as a green solvent. Besides, the selectivity of aryl iodide and aryl bromide over aryl chloride is observed during the C-C coupling reaction. The catalyst could be recovered easily from the reaction mixture using an external magnet device and recycled several times without considerable loss in activity. Additionally, the results of a palladium leaching test of the nano-catalyst demonstrate that no leaching of Pd took place during the C-C coupling process making the procedure environmentally friendly.
A thiosemicarbazone–palladium(II)–imidazole complex as an efficient pre-catalyst for Suzuki–Miyaura cross-coupling reactions at room temperature in aqueous media
Baruah, Jayantajit,Gogoi, Rajjyoti,Gogoi, Nibedita,Borah, Geetika
, p. 683 - 692 (2017)
Abstract: A Pd(II) complex of two sterically crowded ligands, specifically an N,S-donor thiosemicarbazone and an N-donor imidazole, has been synthesized and characterized by physicochemical and spectroscopic methods. X-ray single-crystal analysis revealed that the coordination geometry around the palladium center is distorted square planar, and the chloride ligand is involved in intermolecular bifurcated X–HY-type (where X?=?C, N and Y?=?Cl) hydrogen bonding. This complex proved to be a highly active and retrievable pre-catalyst for additive-free Suzuki–Miyaura cross-coupling reactions of arylboronic acids with aryl bromides or chlorides at room temperature and 60?°C, respectively. The reactions require a low catalyst loading and the complex is converted to ~1.5–2.0 nm-sized Pd nanoparticles (probably the real catalyst). The catalyst can be reused up to seven times without significant loss in activity. Since the reaction proceeds under mild conditions in aqueous medium and the catalyst is recoverable, it provides an environmentally benign alternative to the existing protocols for Suzuki–Miyaura reactions. Graphical abstract: Biaryls can be synthesized in high yield under greener reaction conditions in the presence of efficient pre-catalyst, thiosemicarbazone–palladium(II)–imidazole.[Figure not available: see fulltext.].
A simple, quick and novel protocol for biaryl synthesis using LiCl-promoted in situ-generated Pd nanoparticles
Phukan, Parmita,Boruah, Preeti Rekha,Gehlot, Praveen Singh,Kumar, Arvind,Sarma, Diganta
, (2018)
This paper describes a simple and a very quick protocol for biaryl synthesis using the Suzuki–Miyaura cross-coupling reaction. A quintessential role of salting-out agent LiCl was observed in the Suzuki–Miyaura cross-coupling reaction that enhanced the red
Catalytic properties of palygorskite supported Ru and Pd for efficient oxidation of alcohols
Yang, Zhi-Wang,Zhao, Xia,Li, Tian-Jing,Chen, Wen-Long,Kang, Qiao-Xiang,Xu, Xue-Qing,Liang, Xi-Xi,Feng, Ying,Duan, Huan-Huan,Lei, Zi-Qiang
, p. 34 - 40 (2015)
Natural palygorskite (PG) was employed to prepare cost-effective, reusable supported catalyst of Pd/PG and Ru/PG through wet impregnation method. The catalysts were characterized through AFM, ICP-AES, XPS, XRD, BET, TEM and FTIR. The catalytic properties of the synthesized catalysts were assessed and optimized through oxidation of alcohols with PhIO as oxidant. It showed that the existence of Ru and Pd in the catalysts dramatically enhanced the catalytic activity with a prominent selectivity of far more than 99% compared with the palygorskite.
Application of Pd-2A3HP-MCM-41 to the Suzuki, Heck and Stille coupling reactions and synthesis of 5-substituted 1H-tetrazoles
Nikoorazm, Mohsen,Ghorbani-Choghamarani, Arash,Khanmoradi, Maryam
, p. 705 - 712 (2016)
An ecofriendly heterogeneous catalyst has been synthesized by anchoring palladium onto the surface of organically modified mesoporous silica. The prepared catalyst was characterized using X-ray diffraction, Fourier transform infrared and energy-dispersive X-ray spectroscopies, transmission and scanning electron microscopies, inductively coupled plasma and thermogravimetric techniques. The catalyst shows high activity in the Suzuki, Heck and Stille cross-coupling reactions and the synthesis of 5-substituted 1H-tetrazoles from sodium azide (NaN3). These methods have the advantages of high yields, green reaction conditions, simple methodology and easy separation and workup.
Pillar[5]arene-Based Organometallic Cross-Linked Polymer: Synthesis, Structure Characterization, and Catalytic Activity in the Suzuki-Miyaura Coupling Reaction
Liu, Yuezhou,Lou, Baohui,Shangguan, Liqing,Cai, Jingsong,Zhu, Huangtianzhi,Shi, Bingbing
, p. 1351 - 1356 (2018)
Heterogeneous catalysts, as an emerging research hotspot, have showed excellent advantages on stability, recyclability, and separation from reactant compared with homogeneous catalysts in recent years. Herein, pillar[5]arene-based organometallic cross-linked polymer (P[5]-OCP) was constructed via the complexation between imidazolium-derivatived pillar[5]arene (P[5]) and Pd(OAc)2. The chemical compositions and structure of the P[5]-OCP were confirmed by means of multiple characterization methods. The catalytic activity and process of P[5]-OCP were emphatically investigated in the Suzuki-Miyaura coupling reaction. The P[5]-OCP showed outstanding catalytic activity in mild reaction conditions. Meanwhile, the catalyst P[5]-OCP possessed excellent stability and recyclability, which could be reused at least five times without significant loss of activity. Furthermore, the P[5]-OCP is easily synthesized and cost-effective, which make it a candidate for applications in fine chemical engineering. [Figure Presented]
Simple amine/Pd(OAc)2-catalyzed Suzuki coupling reactions of aryl bromides under mild aerobic conditions
Tao, Bin,Boykin, David W.
, p. 4330 - 4335 (2004)
A new palladium catalyst (DAPCy) made from Pd(OAc)2 and commercially available, inexpensive dicyclohexylamine has been developed for the Suzuki coupling reaction of aryl bromides with boronic acids to give the coupling products in good to high yields. The air-stable catalyst was characterized and well-defined by X-ray crystallography. A catalytic system involving DAPCy in dioxane demonstrates a temperature-dependent reactivity toward aryl bromides with different electronic substituents, and selectively couples electron-deficient aryl bromides with boronic acids over electron-rich ones at room temperature. Another catalytic system employing DAPCy in EtOH provides a general and convenient method to prepare biaryls from aryl bromides and boronic acids with a broad range of functional groups at room temperature and under aerobic conditions.
Schiff-based Pd(II)/Fe(III) bimetallic self-assembly monolayer—preparation, structure, catalytic dynamic and synergistic
Huang, Pingping,Song, Erran,Sun, Yimeng,Li, Tiesheng,Wei, Donghui,Liu, Minghua,Wu, Yangjie
, p. 75 - 86 (2019)
Graphene oxide supported Pd (II)/Fe (III) bimetallic catalytic monolayer (denoted as GO@H-Pd/Fe) was prepared and characterized. Its catalytic performances for Suzuki coupling reaction, synergetic effect and catalytic mechanism were systematic investigated. Results showed that orientation, composition and distribution of catalyst had efficient effect on catalytic activity. Catalytic activity of GO@H-Pd0.10/Fe0.90 was 475 times more than that of GO@H-Pd due to the ordered catalytic monolayer immobilized on GO, proper ratio of Pd/Fe and the synergetic effect between Pd(II) and Fe(III) which could form active cluster containing Pd and Fe. The Pd(II) could be made more negative by transferring electron from GO to Fe(III) via ligand and then to Pd, improving its catalytic activity since it was easy for oxide addition. It also exhibited better stability and recyclability at least 8 times due to proper functional ligand and support. Deactivation mechanism was confirmed to be the aggregation of active centre during the recycling. Heterogeneous catalytic mechanism was also proved by poison test, hot filtration and ReactIR. The results of ReactIR presented different dynamic catalytic process for GO@H-Pd0.10Fe0.90 and homogeneous catalyst (Li2PdCl4/FeCl3·6H2O).The activation energies were 9.7 KJ/mol and 3.7 KJ/mol obtained for heterogeneous and homogeneous catalyst, respectively. Considering the diffusion effect, the factor of supports on the activity was also investigated by ReactIR, with which that GO@H-Pd0.10Fe0.90 catalytic activity was higher than that of homogeneous catalyst could be confirmed.
S-Benzylisothiourea complex of palladium on magnetic nanoparticles: A highly efficient and reusable nanocatalyst for synthesis of polyhydroquinolines and Suzuki reaction
Ghorbani-Choghamarani, Arash,Tahmasbi, Bahman,Moradi, Zahra
, (2017)
S-Benzylisothiourea complex of palladium supported on modified Fe3O4 magnetic nanoparticles (Pd-SBTU@Fe3O4) is reported for carbon–carbon coupling through the Suzuki coupling reaction. Also, the synthesis of pol
Thiourea bridged periodic mesoporous organosilica with ultra-small Pd nanoparticles for coupling reactions
Doustkhah, Esmail,Rostamnia, Sadegh,Imura, Masataka,Ide, Yusuke,Mohammadi, Shiva,Hyland, Christopher J. T.,You, Jungmok,Tsunoji, Nao,Zeynizadeh, Behzad,Yamauchi, Yusuke
, p. 56306 - 56310 (2017)
A synthesis of thiourea-bridged mesoporous organosilica is reported. Using transmission electron microscopy, low-angle XRD measurements and N2 adsorption-desorption isotherms the formation of a highly ordered mesoporous structure with a high surface area (>400 m2 g-1) has been confirmed. Deposition of Pd nanoparticles inside the mesopores resulted in a material that showed excellent catalytic activity in a Suzuki-coupling reaction and retained this activity over several consecutive runs.
A new recyclable/reusable ionic liquid/LiCl system for Suzuki-Miyaura cross coupling reactions
Boruah, Preeti Rekha,Koiri, Milon J.,Bora, Utpal,Sarma, Diganta
, p. 2423 - 2425 (2014)
Suzuki-Miyaura cross coupling reactions of aryl halides with aryl boronic acids were carried out in basic ionic liquids in the presence of lithium chloride as a promoter. The coupling reactions, carried out in the absence of base and ligand, proceed in good to excellent yields with easy product isolation and catalyst recycle.
Pd embedded N, S co-doped graphene wrapped core-shell magnetic nanospheres: Engineered stable nanocatalyst for Suzuki couplings
Rohani, Sahar,Mohammadi Ziarani, Ghodsi,Badiei, Alireza
, (2019)
Designed nitrogen and sulfur co-doped graphene wrapped magnetic core-shell supported Pd nanoparticles were synthesized through the following steps. Firstly, Fe3O4 was prepared, coated with silica and then functionalized with amine groups to create a positive charge on the structure for enhancing the interaction of the Fe3O4@SiO2 with graphene oxide. Secondary, the pre-catalyst wrapped with graphene to enhance adsorption of aromatic substrates through π–π stacking. Thirdly, graphene was doped with nitrogen and sulfur to increase the grafting of Pd in hybrid. Finally, Pd NPs were attached on the surface of pre-engineered structure to produce Fe3O4@SiO2@N,S-wG@Pd which exhibited high performance in Suzuki reactions. This superior activity can be indexed to the incorporation of N and S atoms into graphene led to high anchoring and well-dispersion of Pd NPs on the nanocomposite surface offering large amounts of active centers, that strongly increased the interaction between Pd and substrates to decreases Pd leaching.
Ni2O3-around-Pd hybrid on graphene oxide: An efficient catalyst for ligand-free Suzuki-Miyaura coupling reaction
Nie, Renfeng,Shi, Juanjuan,Du, Weichen,Hou, Zhaoyin
, p. 1 - 6 (2014)
Ni2O3-around-Pd hybrid can be fabricated on graphene oxide (Pd-Ni/RGO) by a simple one-pot wet chemical route. These isolated Pd clusters showed significantly improved performance for Suzuki coupling reaction compared to that of pure Pd/RGO, Ni2O3/RGO, popularly reported Pd/AC, as well as homogeneous PdCl2 and PdCl 2(PPh3)2. Characterizations disclosed that Ni2O3 plays multiple roles in exfoliating graphene sheets, mediating the size as well as stability of Pd clusters. Pd-Ni/RGO dispersed homogeneously in the aqueous reaction mixture, exhibited high enrichment towards reactants as well as extremely high activity and stability for the Suzuki coupling reaction. The best turnover frequencies of all Pd atoms reached 38,750 h-1 at 80 C for bromobenzene coupling. It was concluded that the intimate interaction between Ni2O3 nanoparticles and Pd clusters appears to be beneficial for activating the Pd surface for the catalytic cycle.
Salicylaldoxime-functionalized poly(ethylene glycol)-bridged dicationic ionic liquid ([salox-PEG1000-DIL][BF4]) as a novel ligand for palladium-catalyzed Suzuki-Miyaura reaction in water
Wang, Yinglei,Luo, Jun,Liu, Zuliang
, p. 601 - 605 (2013)
Two novel salicylaldoxime-functionalized poly(ethylene glycol)-bridged dicationic ionic liquids ([salox-PEG1000-DIL][BF4] and [salox-PEG1000-DIL][PF6]) were prepared and characterized. [salox-PEG1000-DIL][BF4] was found to be an efficient and recyclable ligand for palladium-catalyzed Suzuki-Miyaura reaction in water. The catalytic system could be easily recovered and reused for at least five runs only with slight decrease in its activity. Copyright
Synthesis and Characterization of Pd Schiff Base Complex Immobilized onto Functionalized Nanoporous MCM-41 and its Catalytic Efficacy in the Suzuki, Heck and Stille Coupling Reactions
Khanmoradi, Maryam,Nikoorazm, Mohsen,Ghorbani-Choghamarani, Arash
, p. 1114 - 1126 (2017)
Abstract: The present work describes the use of palladium-vanillin-Schiff-base complex immobilized on MCM-41 nanostructure as efficient catalyst for the Suzuki–Miyaura, Stille and Mizoroki–Heck reactions of several aryl halides under aerobic conditions. All the reactions were carried out in green solvents (H2O and PEG-400). The developed procedure results bring several benefits such as uses of inexpensive and non-toxic ligand (vanillin), easy catalyst/product separation and catalyst recycling. The catalyst can be reused at least for five consecutive cycles without a significant loss of its catalytic activity or metal leaching. Graphical Abstract: [Figure not available: see fulltext.].
Magnetic nanoparticles supported oxime palladacycle as a highly efficient and separable catalyst for room temperature Suzuki-Miyaura coupling reaction in aqueous media
Gholinejad, Mohammad,Razeghi, Mehran,Najera, Carmen
, p. 49568 - 49576 (2015)
A novel magnetic nanoparticle-supported oxime palladacycle catalyst was successfully prepared and characterized. The magnetically recoverable catalyst was evaluated in the room temperature Suzuki-Miyaura cross-coupling reaction of aryl iodides and bromides in aqueous media. The catalyst was shown to be highly active under phosphine-free and low Pd loading (0.3 mol%) conditions. The catalyst could be easily separated from the reaction mixture using an external magnet and reused for six consecutive runs without significant loss of activity.
Facile construction & modeling of a highly active thiacalixphenyl[4]arene-protected nano-palladium catalyst for various C-C cross-coupling reactions
Modi, Krunal,Patel, Chirag,Panchal, Urvi,Liska, Alan,Kongor, Anita,Jiri, Ludvik,Jain
, p. 5611 - 5622 (2019)
The design and creation of thiacalixphenyl[4]arene tetraacetohydrazide (TPTAH) has been utilized for the construction of palladium nanoparticles (PdNps). The molecular modelling studies give an insight into the surface properties of TPTAH capped PdNps. The plausible reduction mechanism of Pd(ii) to Pd(0) is due to the presence of hydrazide group on the periphery. The charge transfer for this reduction was initiated by the carbonyl group and N-atom. TPTAH behaves as a reducing and stabilizing agent for the formation of catalytically active TPTAH-PdNps that were characterized by UV-Vis spectroscopy, selected area electron diffraction (SAED), transmission electron microscopy (TEM), and powder X-ray diffraction. The TPTAH-PdNps with size 4 ± 2 nm were found to be catalytically active for C-C cross-coupling reactions such as the Suzuki-Miyaura, Heck, and Stille reactions. TPTAH-PdNps are superior to the conventional Pd catalyst in terms of yield, catalyst loading, reaction time, and recyclability.
New Palladium – ZrO2 Nano-Architectures from Thermal Transformation of UiO-66-NH2 for Carbonylative Suzuki and Hydrogenation Reactions
Alsalahi, Waleed,Augustyniak, Adam W.,Tylus, W?odzimierz,Trzeciak, Anna M.
supporting information, (2021/12/22)
The new nanocomposites, Pd/C/ZrO2, PdO/ZrO2, and Pd/PdO/ZrO2, were prepared by thermal conversion of Pd@UiO-66-Zr?NH2 (MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly distributed on the ZrO2 or C/ZrO2 matrix, was evidenced by transmission electron microscopy, scanning electron microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS) methods. All pyrolysed composites retained the shape of the MOF template. They catalyze carbonylative Suzuki coupling under 1 atm CO with an efficiency significantly higher than the original Pd@UiO-66-Zr?NH2. The most active PdO/ZrO2 composite, formed benzophenone with TOF up to 1600 h?1, while by using Pd@UiO-66-Zr?NH2, much lower TOF values, 51–95 h?1, were achieved. After the reaction, PdO/ZrO2 was recovered with the same composition and catalytic activity. Very good results were also obtained in the transfer hydrogenation of benzophenones to alcohols with Pd/C/ZrO2 and PdO/ZrO2 catalysts under microwave irradiation.
Potent Inhibition of Nicotinamide N-Methyltransferase by Alkene-Linked Bisubstrate Mimics Bearing Electron Deficient Aromatics
Buijs, Ned,Campagna, Roberto,Emanuelli, Monica,Gao, Yongzhi,Gutiérrez-De-Terán, Hugo,Innocenti, Paolo,Jespers, Willem,Martin, Nathaniel I.,Parsons, Richard B.,Sartini, Davide,Van Haren, Matthijs J.,Van Westen, Gerard J. P.,Zhang, Yurui
, p. 12938 - 12963 (2021/09/11)
Nicotinamide N-methyltransferase (NNMT) methylates nicotinamide (vitamin B3) to generate 1-methylnicotinamide (MNA). NNMT overexpression has been linked to a variety of diseases, most prominently human cancers, indicating its potential as a therapeutic target. The development of small-molecule NNMT inhibitors has gained interest in recent years, with the most potent inhibitors sharing structural features based on elements of the nicotinamide substrate and the S-adenosyl-l-methionine (SAM) cofactor. We here report the development of new bisubstrate inhibitors that include electron-deficient aromatic groups to mimic the nicotinamide moiety. In addition, a trans-alkene linker was found to be optimal for connecting the substrate and cofactor mimics in these inhibitors. The most potent NNMT inhibitor identified exhibits an IC50 value of 3.7 nM, placing it among the most active NNMT inhibitors reported to date. Complementary analytical techniques, modeling studies, and cell-based assays provide insights into the binding mode, affinity, and selectivity of these inhibitors.
