- Synthesis of functionalized benzothiophenes by twofold Heck and subsequent 6π-electrocyclization reactions of 2,3-dibromothiophene
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The Heck reaction of 2,3-dibromothiophene afforded 2,3-di(alkenyl)thiophenes which were transformed into benzothiophenes by domino ′6π-electrocyclization/dehydrogenation′ reactions.
- Toguem, Serge-Mithérand Tengho,Hussain, Munawar,Malik, Imran,Villinger, Alexander,Langer, Peter
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Read Online
- Pd-Catalyzed desulfitative arylation of olefins by: N -methoxysulfonamide
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A novel Pd-catalyzed protocol for the desulfitative Heck-type reaction of N-methoxy aryl sulfonamides with alkenes was reported. The cross-coupling reaction was performed successfully with a variety of olefins to obtain aryl alkenes. Different substituents on the aromatic ring of N-methoxysulfonamides were also found to be compatible with the reaction conditions. Expectedly, the reaction proceeds through CuCl2-promoted generation of the nitrogen radical and subsequent desulfonylation under thermal conditions to afford the aryl radical for the Pd-catalyzed coupling reaction. N-Methoxysulfonamide was further exploited for the synthesis of symmetrical biaryls in the presence of CuCl2. This journal is
- Ojha, Subhadra,Panda, Niranjan
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supporting information
p. 1292 - 1298
(2022/02/19)
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- Pd salen complex@CPGO as a convenient, effective heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions
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A Pd(II) Schiff base complex supported on graphene oxide nanosheets (Pd(II) salen@CPGO) has been synthesized and characterized by FT-IR, ICP-AES, XRD, SEM/EDX and TEM. The synthesized nanocatalyst has been found to be an efficient heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki coupling reactions. Pd(II) salen@CPGO could be separated and recovered easily from the reaction mixture and recycled several times without a discernible decrease in its catalytic activity. The construction of a solid sheet-supported Pd catalyst would be expected to be a promising system to perform heterogeneous catalytic reactions.
- Ghabdian, Mahdieh,Nasseri, Mohammad Ali,Allahresani, Ali,Motavallizadehkakhky, Alireza
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p. 1713 - 1728
(2018/05/25)
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- Pd nanoparticles supported on reduced graphene oxide as an effective and reusable heterogeneous catalyst for the Mizoroki–Heck coupling reaction
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A general method for the synthesis of palladium nanoparticles loaded on reduced graphene oxide functionalized with diethylenetriamine (PdNPs/rGO-NH2) using a sonochemical procedure is described. The heterogeneous nanocomposite was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, thermogravimetric analysis, high-angle annular dark field scanning transmission electron microscopy, X-ray photoelectron spectroscopy, UV–visible absorption, and inductively coupled plasma optical emission spectrometry. The PdNPs/rGO-NH2 was very effective for the Mizoroki–Heck coupling reaction of several aryl iodide compounds with different alkenes in the presence of triethylamine. The reaction provides the coupling products in good to excellent yields (59–100%). Additionally, the PdNPs/rGO-NH2 catalyst can be reutilized for six successive runs without any apparent diminution of its catalytic reactivity.
- Mirza-Aghayan, Maryam,Mohammadi, Marzieh,Addad, Ahmed,Boukherroub, Rabah
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- Organoselenium-palladium(ii) complex immobilized on functionalized magnetic nanoparticles as a promising retrievable nanocatalyst for the "phosphine-free" Heck-Mizoroki coupling reaction
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In the present study, for the first time, an air- and moisture-stable organoselenium-palladium complex immobilized on silica-coated magnetic nanoparticles was designed, synthesized and applied as a practical and retrievable catalyst in organic synthesis. The chemical nature and structure of this novel catalytic system were characterized using various techniques such as Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy and vibrating sample magnetometry (VSM). Subsequently, the catalytic performance of the synthesized nanocatalyst was investigated in the Heck-Mizoroki cross-coupling reaction and excellent results are obtained. The low catalyst loading, wide substrate scope, high yield, short reaction time, simple separation from the reaction mixture and importantly, the longevity of the nanocatalyst for at least five successive recycles without significant degradation in its activity are the main merits of this protocol. Above all, this work opens up attractive and interesting routes for the use of organoselenium compounds as efficient ligands for the synthesis of heterogeneous catalysts.
- Rangraz, Yalda,Nemati, Firouzeh,Elhampour, Ali
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p. 15361 - 15371
(2018/09/29)
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- Novel cyclodextrin-modified h-BN@Pd(II) nanomaterial: An efficient and recoverable catalyst for ligand-free C-C cross-coupling reactions in water
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An environmentally friendly palladium(II) catalyst supported on cyclodextrin-modified h-BN was successfully prepared. The catalyst was characterized by FT-IR, SEM, TG, XRD and XPS, and the loading level of Pd in h-BN@β-CD@Pd(II) was measured to be 0.088?mmol g?1 by ICP. It exhibits excellent catalytic activity for the Suzuki and Heck reactions in water, and can be easily separated and consecutively reused for at least nine times. In addition, a series of pharmacologically interesting products were successfully synthesized using this catalyst to demonstrate its potential applications in pharmaceutical industries. Above all, this work opens up an interesting and attractive avenue for the use of cyclodextrin-functionalized h-BN as an efficient support for hydrophilic heterogeneous catalysts.
- Ma, Xiaojun,Lv, Guanghui,Cheng, Xu,Li, Weijian,Sang, Rui,Zhang, Yong,Wang, Qiantao,Hai, Li,Wu, Yong
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- Thiophene Methanimine–Palladium Schiff Base Complex Anchored on Magnetic Nanoparticles: A Novel, Highly Efficient and Recoverable Nanocatalyst for Cross-Coupling Reactions in Mild and Aqueous Media: Γ-Fe2O3/AEPH2-TC-Pd Catalyzed Suzuki–Miyaura and Heck–Mizoroki Reactions
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Abstract: In this study, a novel thiophene methanimine–palladium Schiff base complex anchored on decorated γ-Fe2O3 with 2-aminoethyl dihydrogen phosphate (γ-Fe2O3/AEPH2-TC-Pd) was synthesized as a new magnetically separable nanocatalyst. Characterization of the new designed nanocatalyst was performed successfully using different techniques such as FT-IR, XRD, XPS, TEM, TGA, VSM, ICP and elemental analysis. This nanocatalyst presented a superb catalytic activity for Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions. The most important features of the prepared catalytic system which makes the current protocol more beneficial from both industrial and environmental viewpoints are its ease of recovery and reusability up to nine cycles without appreciable loss of the catalytic performance, as well as accomplishing the reactions under mild conditions in aqueous media which is a great challenge in some cross-coupling reactions. Graphical Abstract: [Figure not available: see fulltext.].
- Jahanshahi, Roya,Akhlaghinia, Batool
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p. 2640 - 2655
(2017/09/06)
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- Aminophosphine Palladium(0) Complex Supported on ZrO2 Nanoparticles (ZrO2@AEPH2-PPh2-Pd(0)) as an Efficient Heterogeneous Catalyst for Suzuki–Miyaura and Heck–Mizoroki Reactions in Green Media
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Abstract: A new aminophosphine palladium(0) complex supported on ZrO2nanoparticles (ZrO2@AEPH2-PPh2-Pd(0)) was successfully synthesized and characterized using FT-IR, XRD, XPS, SEM, TEM, EDS, TGA and ICP techniques. Characterization results revealed that the synthesized catalyst had tetragonal and monoclinic structure with spherical morphology. The prepared nanocatalyst was showed excellent reactivity in the Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions. Moreover, this nanocatalyst can be easily recovered and reused for at least six cycles without deterioration in catalytic activity. Graphical Abstract: [Figure not available: see fulltext.]
- Razavi, Nasrin,Akhlaghinia, Batool,Jahanshahi, Roya
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p. 360 - 373
(2017/02/18)
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- Ligand-Free C–C Coupling Reactions Promoted by Hexagonal Boron Nitride-Supported Palladium(II) Catalyst in Water
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A micron-scale palladium(II) material has been successfully prepared using Schiff base-modified hexagonal boron nitride as a support and used for the first time as an efficient and recyclable catalyst in organic synthesis. The morphology, composition, metal loading and thermal stability of the catalyst were studied using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), infrared spectroscopy (FT-IR), inductively coupled plasma (ICP) and thermogravimetric (TG) analyses. Then, the micron material was tested in various C–C cross-coupling reactions and exhibited excellent catalytic activities in the Suzuki and Heck reactions. Moreover, the catalyst could be easily recovered by simple filtration and reused at least ten times without significant loss of its catalytic activity. In general, this work demonstrates the possibility of using Schiff-base@hexagonal boron nitride as an efficient support for heterogeneous catalysts. (Figure presented.).
- Cheng, Xu,Li, Weijian,Nie, Ruifang,Ma, Xiaojun,Sang, Rui,Guo, Li,Wu, Yong
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supporting information
p. 454 - 466
(2017/02/10)
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- Flexible, dicationic imidazolium salts for in situ application in palladium-catalysed Mizoroki–Heck coupling of acrylates under aerobic conditions
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The synthesis, characterization and in situ catalytic performance of new unsymmetric N,N′-disubstituted imidazolium-based dicationic salts in Mizoroki–Heck coupling of acrylates with aryl bromides under aerobic conditions are described. A series of flexible dicationic salts with varying steric and electronic properties were synthesized in good to excellent yields. All the salts were well characterized using spectroscopic techniques. X-ray diffraction analysis of two salts with the same dicationic backbone and different counter anions shows that the ligand adopts two different conformations which are influenced by the nature of the anion. Thus, the ligand is capable of changing its conformation according to the change in environment due to its flexible nature. All the synthesized imidazolium salts were found to be active in in situ palladium-catalysed Mizoroki–Heck coupling under aerobic conditions. Amongst the salts, the hydroxyl-functionalized imidazolium salt, incorporating the features of both bidentate chelating O,O ligand and carbene, shows the maximum catalytic activity. A variety of aryl and heteroaryl methyl and ethyl cinnamates were synthesized using these imidazolium salts as preligands. In addition, NMR studies confirm in situ generation of normal N-heterocyclic carbenes from the C-2 position of imidazol-2-ylidene ring. The mercury poisoning test was also performed to ascertain the nature of catalytically active palladium species. Aerobic conditions, low catalytic loading (0.5?mol%), shorter reaction times, broad functional group tolerance and good to excellent isolated yields are some of the significant features of the novel catalytic systems described here. Copyright
- Milton, Marilyn Daisy,Garg, Parul
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p. 759 - 766
(2016/09/04)
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- Palladium(II)-Schiff base complex immobilized covalently on h-BN: An efficient and recyclable catalyst for aqueous organic transformations
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A moisture- and air-stable palladium(II)-Schiff base complex supported on h-BN was simply prepared by using commercially available reagents. This nanomaterial was applied as an excellent and recyclable heterogeneous catalyst for the Suzuki and Heck cross-coupling reactions. And it has been characterized by FT-IR, XRD, SEM, XPS, TG and ICP-AES techniques. High yields, ligand-free, low reaction time, water as solvent, non-toxicity and recyclability of the catalyst are the main merits of these protocols. In addition, a series of pharmacologically relevant products were successfully synthesized using this catalyst. Above all, this work opens up an interesting and attractive avenue for the use of h-BN as an efficient support for heterogeneous catalysts.
- Li, Weijian,Lv, Guanghui,Cheng, Xu,Sang, Rui,Ma, Xiaojun,Zhang, Yong,Nie, Ruifang,Li, Jie,Guan, Mei,Wu, Yong
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supporting information
p. 8557 - 8564
(2016/12/07)
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- Immobilized palladium nanoparticles on potassium zirconium phosphate as an efficient recoverable heterogeneous catalyst for a clean Heck reaction in flow
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Palladium nanoparticles on layered potassium α-zirconium phosphate (PdNP/α-ZrPK) with high palladium loading (10.6 wt%) have been prepared and used as catalyst in low amount (0.1 mol% of Pd) in the Heck reaction of methyl acrylate and styrene with a series of aryl iodides in CH3CN/H2O azeotrope as a green medium. The procedure has been optimized under flow conditions obtaining an extremely low waste production (E-factor) and allowing to isolate the final product with very low residual palladium content without any purification step.
- Petrucci, Chiara,Cappelletti, Matteo,Piermatti, Oriana,Nocchetti, Morena,Pica, Monica,Pizzo, Ferdinando,Vaccaro, Luigi
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- Cross-Linked Thiazolidine Network as Support for Palladium: A New Catalyst for Suzuki and Heck Reactions
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A thiazolidine-based material was used for the first time as support for palladium. The support was prepared by starting from a highly cross-linked thiazolium-based material, obtained by radical oligomerization of a bisvinylthiazolium dibromide salt in the presence of 3-mercaptopropyl-modified silica SBA-15. Palladium was immobilized by treatment with tetrachloropalladate salt. Reduction with sodium borohydride afforded a thiazolidine-based material that acted as ligands for the Pd species. The thiazolidine-based palladium catalyst was fully characterized and, working in only 0.1 mol% amount, displayed good activity in the Suzuki-Miyaura and in the Heck reactions. Several biphenyl and alkene compounds could be prepared in high yields. The catalytic material proved to be fully recoverable and it was representatively used for three times in the Suzuki-Miyaura reaction without showing any decrease in its activity.
- Bivona, Lucia Anna,Giacalone, Francesco,Vaccaro, Luigi,Aprile, Carmela,Gruttadauria, Michelangelo
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p. 2526 - 2533
(2015/08/24)
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- Phosphine-catalyzed domino reactions: A route to functionalized bicyclic skeletons
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A novel strategy that involves phosphine-catalyzed sequential [2+3] and [3+2] annulation reactions was developed. In this domino reaction, γ-substituted allenoates were used as novel C4 synthons, and the bicyclic cyclopenta[b]dihydrofuran derivatives were produced in good to excellent diastereoselectivities and yields under mild conditions. Furthermore, preliminary studies on an asymmetric variant of this reaction proceeded with moderate enantioselectivity.
- Li, Erqing,Huang, You
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supporting information
p. 3520 - 3527
(2014/04/03)
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- Efficient screening and library generation in parallel C-C coupling reactions mediated by Organosilica SiliaCat palladium catalysts
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Organosilica SiliaCat palladium catalysts applied to the conversion of widely different substrates in Suzuki, Sonogashira, and Heck coupling reactions run in a parallel synthesizer enable quick screening of the reaction system with identification of the best reaction conditions and rapid library generation.
- Pandarus, Valerica,Gingras, Genevieve,Beland, Francois,Ciriminna, Rosaria,Pagliaro, Mario
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scheme or table
p. 117 - 122
(2012/06/01)
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- 2,2′-Diamino-6,6′-dimethylbiphenyl as an efficient ligand in the palladium- catalyzed SuzukiMiyaura and MizorokiHeck reactions
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2,2′-Diamino-6,6′-dimethylbiphenyl was found to be an efficient ligand in the palladium-catalyzed SuzukiMiyaura coupling reactions of awl iodides, bromides, and chlorides and Mizoroki1-Ieck reactions of awl iodides and bromides. Under appropriate conditions, all reactions gave the desired products in moderate to excellent yields. The ligand is inexpensive, air-stable and easy to available.
- Lu, Jian-Mei,Ma, Hui,Li, Sha-Sha,Ma, Dan,Shao, Li-Xiong
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experimental part
p. 5185 - 5189
(2010/08/20)
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- The synthesis and applications of a micro-pine-structured nanocatalyst
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Dendritic nanoferrites with a micro-pine morphology have been synthesized for the first time under microwave irradiation conditions without using any reducing or capping reagent; the nanoferrites were then functionalized and coated with Pd metal, which catalyzes various organic transformations. The Royal Society of Chemistry 2008.
- Polshettiwar, Vivek,Nadagouda, Mallikarjuna N.,Varma, Rajender S.
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supporting information; experimental part
p. 6318 - 6320
(2009/04/13)
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- TRICYCLIC HETEROARYL PIPERAZINES, PYRROLIDINES AND AZETIDINES AS SEROTONIN RECEPTOR MODULATORS
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The present invention generally relates to a series of compounds, to pharmaceutical compositions containing the compounds, and to use the compounds and compositions as therapeutic agents. More specifically, compounds of the present invention are hexahydro
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Page/Page column 43; 63
(2008/06/13)
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- Water is an efficient medium for Wittig reactions employing stabilized ylides and aldehydes
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Water is demonstrated to be an excellent medium for the Wittig reaction employing stabilized ylides and aldehydes. Although the solubility in water appears to be an unimportant characteristic in achieving good chemical yields and E/Z-ratios, the rate of W
- Dambacher, Jesse,Zhao, Wen,El-Batta, Amer,Anness, Robert,Jiang, Changchun,Bergdahl, Mikael
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p. 4473 - 4477
(2007/10/03)
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- New and efficient conditions for the Z-selective synthesis of unsaturated esters by the Horner-Wadsworth-Emmons olefination
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The Horner-Wadsworth-Emmons reaction of both 1 (Still's reagent) and 2 (Ando's reagent) with aldehydes was studied. Tris[2-(2-methoxyethoxy)ethyl]amine (TDA-1) was shown to be an efficient additive when the reaction was performed in THF at -78°C. Selectivities close to 95% were obtained in the condensation of 1 with aromatic aldehydes. The use of a 5-fold excess of 18C6 in this reaction had already been reported. However, we have defined conditions in which only catalytic amounts are required.
- Touchard, Fran?ois P.
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p. 5519 - 5523
(2007/10/03)
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- An efficient combination of microwave dielectric heating and the use of solid-supported triphenylphosphine for Wittig reactions
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Figure presented Reaction condition: 150°C, 5 min. Olefins could be formed in an efficient way by the use of stable ylides in just a few minutes using microwave dielectric heating. The drawback with the Wittig reaction in solution phase is the formation of 1 equiv of triphenylphosphine oxide. To avoid this, the corresponding protocol using the efficient combination of solid-supported triphenylphosphine and microwave dielectric heating was developed. An even more efficient one-pot three-step Wittig reaction was also developed.
- Westman, Jacob
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p. 3745 - 3747
(2007/10/03)
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