- HBC-porphyrin-close contact chromophores
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A photo/redoxactive hexa-peri-hexabenzocoronene-porphyrin conjugate with a direct connection between the two chromophores was synthesised using a formylated hexaphenylbenzene precursor.
- Englert, Jan M.,Malig, Jenny,Zamolo, Valeria Anna,Hirsch, Andreas,Jux, Norbert
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- Syntheses, structures and efficient catalysis for C-C coupling of some benzaldehyde thiosemicarbazone complexes of palladium
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Reaction of the 4-R-benzaldehyde thiosemicarbazones (denoted in general as L-R; R = OCH3, CH3, H, Cl and NO2) with trans-[Pd(PPh3)2Cl2] afforded a group of mixed-ligand complexes (denoted i
- Paul, Piyali,Datta, Sayanti,Halder, Sarmistha,Acharyya, Rama,Basuli, Falguni,Butcher, Ray J.,Peng, Shie-Ming,Lee, Gene-Hsiang,Castineiras, Alfonso,Drew, Michael G.B.,Bhattacharya, Samaresh
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- Synthesis of new styrylquinoline cellular dyes, fluorescent properties, cellular localization and cytotoxic behavior
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New styrylquinoline derivatives with their photophysical constants are described. The synthesis was achieved via Sonogashira coupling using the newly developed heterogeneous nano-Pd/Cu catalyst system, which provides an efficient synthesis of high purity
- Rams-Baron, Marzena,Dulski, Mateusz,Mrozek-Wilczkiewicz, Anna,Korzec, Mateusz,Cieslik, Wioleta,Spaczyńska, Ewelina,Bartczak, Piotr,Ratuszna, Alicja,Polanski, Jaroslaw,Musiol, Robert
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- Synthesis of fluorescent molecular switches based on porphyrinoids covalently linked with redox active ligands
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5,15-bis(1-hydoxy-2,6-di-tert-butyl-phenyl)10,20-bis-(pentaphenyl-phenyl)phenyl porphyrin and its Nickel complex were synthesized. Oxidation with NOBF4 gave 5,15bis(1-oxo-2,6-ditertairy-butyl-phenyl)10,20-bis(pentaphenyl-phenyl)phenyl-porphodimethene and Ni bis(1-oxo-2,6-ditertairy-butyl-phenyl)10,20-bis-(pentaphenylphenyl)phenyl porphodimethene. The porphyrin conjugates were characterized by NMR, mass, and UV–visible spectroscopy for structural elucidation. The density functional theory studies revealed a decrease in the highest occupied and the lowest unoccupied molecular orbital (HOMO-LUMO) energy gaps in the oxo-porphodimethenes. The photochromism and fluorescence characteristics were also studied. The porphyrin moieties were found to be desirable for the reversible light-driven fluorescent molecular switches.
- Chauhan, Shive M. S.,Mishra, Gaurav Kumar,Nisa, Kharu,Thirumal, M.
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- A Reversible Rhodamine B Based pH Probe with Large Pseudo-Stokes Shift
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A reversible and sensitive pH probe DPE?Rh operates by F?rster resonance energy transfer from 1,2-diphenylethyne (DPE) to Rhodamine B (Rh). In the presence of H+, the spirolactam ring of the Rhodamine B unit was opened and this resulted in ca. 1000-fold enhancement of fluorescence intensity with linear change over the pH range of 2.0 to 5.5. The F?rster resonance energy transfer offered this probe an effective excitation–emission wavelength shift of around 240 nm with about 100 % quenching of the donor emission. The response of the sensor is tolerant towards a wide range of metal ions and the sensing mechanism was deduced by 1H NMR spectrometry. This FRET-based molecule not only provides a sensitive pH probe, but also suggests an effective strategy to eliminate the interference of excitation light.
- Bao, Guochen,Wong, Ka-Leung,Tanner, Peter A.
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- Dissymmetrical U-shaped π-stacked supramolecular assemblies by using a dinuclear CuI clip with organophosphorus ligands and monotopic fully π-conjugated ligands
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Reactions between the U-shaped binuclear CuI complex A that bears short metal-metal distances and the cyano-capped monotopic π-conjugated ligands 1-5 that carry gradually bulkier polyaromatic terminal fragments lead to the formation of π-stacked supramolecular assemblies 6-10, respectively, in yields of 50-80 %. These derivatives have been characterized by multinuclear NMR spectroscopic analysis and X-ray diffraction studies. Their solid-state structures show the selective formation of U-shaped supramolecular assemblies in which two monotopic π-conjugated systems present large (6, 7 , and 9) or medium (8 and 10) intramolecular π overlap, thus revealing π -π interactions. These assemblies self-organize into head-to-tail π-stacked dimers that in turn self-assemble to afford infinite columnar π stacks. The ature, extent, and complexity of the intermolecular contacts within the head-to-tail π-stacked dimer depend on the nature of the terminal polyaromatic fragment carried by the cyano-capped monotopic ligand, but it does not alter the result of the self-assembling process. These results demonstrate that the dinuclear molecular clip A that bears short metal-metal distances allows selective supramolecular assembly processes driven by the formation of intra- and intermolecular short π-π interactions in the resulting self-assembled structures; thus, demonstrating that their shape is not only dictated by the symmetry of the building blocks. This approach opens perspectives toward the formation of extended π-stacked columns based on dissymmetrical and functional π-conjugated systems.
- Moussa, Mehdi El Sayed,Guillois, Kevin,Shen, Wenting,Rau, Rgis,Crassous, Jeanne,Lescop, Christophe
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- ERRγ ligand HPB2 upregulates BDNF-TrkB and enhances dopaminergic neuronal phenotype
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Brain derived neurotrophic factor (BDNF) promotes maturation of dopaminergic (DAergic) neurons in the midbrain and positively regulates their maintenance and outgrowth. Therefore, understanding the mechanisms regulating the BDNF signaling pathway in DAerg
- Kim, Hyo In,Lee, Seungbeom,Lim, Juhee,Chung, Sungkyun,Koo, Tae-Sung,Ji, Yu-Geun,Suh, Young-Ger,Son, Woo Sung,Kim, Seok-Ho,Choi, Hyun Jin
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- Immobilizing Pd nanoparticles on the ternary hybrid system of graphene oxide, Fe3O4 nanoparticles, and PAMAM dendrimer as an efficient support for catalyzing sonogashira coupling reaction
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An alternative approach to develop a Pd catalyst based on dendrimer-functionalized graphene oxide for C-C cross-coupling reactions is reported. Pd@MGO-D-NH2 has been synthesized by incipient wet impregnation method. The structure of the catalyst was thoroughly characterized by a set of analytical techniques such as TEM, BET, SEM/EDS, FTIR, and elemental mapping analysis. Then, the catalytic activity of the catalyst was scrutinized for promoting sonogashira C-C coupling reaction. The results manifested that Pd@MGO-D-NH2 was able to catalyze the coupling reaction to obtain high coupling yields in short reaction time. The results of present work are hoped to aid the development of new class of heterogeneous catalysts as the high performance candidate for industrial applications.
- Tarahomi, Mehrasa,Alinezhad, Heshmatollah,Maleki, Behrooz
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- Zeolitic imidazolate frameworks-67 (ZIF-67) supported PdCu nanoparticles for enhanced catalytic activity in Sonogashira-Hagihara and nitro group reduction under mild conditions
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A bimetallic PdCu supported on amine functionalized ZIF-67 is shown to be efficient catalyst in Sonogashira-Hagihara coupling reaction of aryl iodides at room temperature and aryl bromides at 40 oC. In addition, the catalyst is used in the reduction of 4-
- Gholinejad, Mohammad,Naghshbandi, Zhwan,Sansano, Jose M.
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- Pd supported on clicked cellulose-modified magnetite-graphene oxide nanocomposite for C-C coupling reactions in deep eutectic solvent
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Cellulose-modified magnetite-graphene oxide nanocomposite was prepared via click reaction and utilized for immobilization of palladium (Pd) nanoparticles without using additional reducing agent. The abundant OH groups of cellulose provided the uniform dispersion and high stability of Pd nanoparticles, while magnetite-graphene oxide as a supporting material offered high specific surface area and easy magnetic separation. The as-prepared nanocomposite served as a heterogeneous catalyst for the Heck and Sonogashira coupling reactions in various hydrophilic and hydrophobic deep eutectic solvents (DESs) as sustainable and environmentally benign reaction media. Among the fifteen DESs evaluated for coupling reactions, the hydrophilic DES composed of dimethyl ammonium chloride and glycerol exhibited the best results. Due to the low miscibility of catalyst and DES in organic solvents, the separated aqueous phase containing both of the catalyst and DES can be readily recovered by evaporating water and retrieved eight times with negligible loss of catalytic performance.
- Karimi, Sabah,Masteri-Farahani, Majid,Niakan, Mahsa,Shekaari, Hemayat
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- Metal scavenging and catalysis by periodic mesoporous organosilicas with 2,2′-bipyridine metal chelating ligands
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A periodic mesoporous organosilica containing 2,2′-bipyridine (BPy-PMO) was assessed as a metal scavenger and heterogeneous catalyst. The functionalized PMO was synthesized based on a modified version of a previously reported procedure and showed a large
- Waki, Minoru,Inagaki, Shinji
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- Aerobic Cu and amine free Sonogashira and Stille couplings of aryl bromides/chlorides with a magnetically recoverable Fe3O4@SiO2 immobilized Pd(II)-thioether containing NHC
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Two value added C–C cross coupling reactions; Sonogashira and Stille couplings were achieved at milder conditions in the catalytic presence of a magnetically recoverable heterogeneous catalyst Fe3O4@SiO2@NHC^SPh-Pd(II). The catalyst was earlier reported for Suzuki-Miyaura reaction, and as an extension of its catalytic efficiency, the Stille and Sonogashira cross coupling reactions under aerobic condition has been explored in present report. The Sonogashira coupling of aryl bromides and terminal alkynes produced an excellent yield (~96% at 0.25 mol% Pd) of the desired coupling product under copper and amines free conditions. Moreover, an excellent Stille coupling of readily available and more latent aryl chlorides and trialkylstannane was obtained (yields up to 95% at 0.25 mol% Pd) in absence of toxic fluorides additives. The broad substrate scope of the catalyst for both the coupling reactions and the magnetically recoverable feature of catalyst make this reaction highly desirable for industrial applications of present heterogeneous catalysis.
- Khandaka, Himanshu,Sharma, Kamal Nayan,Joshi, Raj Kumar
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supporting information
(2021/02/20)
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- A Waste-Minimized Approach to Cassar-Heck Reaction Based on POLITAG-Pd0 Heterogeneous Catalyst and Recoverable Acetonitrile Azeotrope
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Three different Pd0-based heterogeneous catalysts were developed and tested in the Cassar–Heck reaction (i. e., copper-free Sonogashira reaction) aiming at the definition of a waste minimized protocol. The cross-linked polymeric supports used in this investigation were designed to be adequate for different reaction media and were decorated with different pincer-type ionic ligands having the role of stabilizing the formation and dimension of palladium nanoparticles. Among the ionic tags tested, bis-imidazolium showed the best performances in terms of efficiency and durability of the metal catalytic system. Eventually, aqueous acetonitrile azeotrope was selected as the reaction medium as it allowed the best catalytic efficiency combined with easy recovery and reuse. Finally, the synergy between the selected catalyst and reaction medium allowed to obtain highly satisfactory isolated yields of a variety of substrates while using a low amount of metal catalyst. The high performance of the designed POLymeric Ionic TAG (POLITAG)-Pd0, along with its good selectivity achieved in a copper-free process, also led to a simplified purification procedure allowing the minimization of the waste generated as also proven by the very low E-factor values (1.4–5) associated.
- Valentini, Federica,Ferlin, Francesco,Tomarelli, Elena,Mahmoudi, Hamed,Bagherzadeh, Mojtaba,Calamante, Massimo,Vaccaro, Luigi
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p. 3359 - 3366
(2021/07/28)
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- Immobilized Pd on a NHC-functionalized metal-organic FrameworkMIL-101(Cr): An efficient heterogeneous catalyst in the heck and copper-free Sonogashira coupling reactions
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A heterogeneous palladium catalyst system based on immobilization of palladium moieties on a N-heterocyclic carbene (NHC) modified metal organic framework (MOF) was developed for the Heck and copper-free Sonogashira coupling reactions. In order to prepare this catalyst system, first, MIL-101(Cr) was functionalized with NHC moieties through a post synthetic modification (PSM) approach, and then Pd metal was stabilized on the prepered MIL-101(Cr)-NHC substrate. This material was characterized using various microscopic and spectroscopic techniques and then was used as an efficient heterogeneous Pd catalyst system in the Heck and copper-free Sonogashira reactions. Results of the heterogeneity tests showed that the Pd-NHC-MIL-101(Cr) catalyst can efficiently catalyzed these coupling reactions heterogeneously and no remarkable changes observed in the morphology and structure of MIL-101(Cr) template during the reaction progress. Also, existence of palladium nanoparticles immobilized on the MOF structure affirmed by the TEM and XPS analysis confirmed the oxidation state of Pd. A variety of alkene and alkyne derivatives were synthesized in good to excellent yields using this heterogeneous Pd catalyst system under normal conditions. More importantly Pd-NHC-MIL-101(Cr) catalyst was simply recovered from the reaction medium without remarkable decreasing in its catalytic activities after five times of reusability. The ICP analysis showed the very low Pd and Cr metals leaching, representing high stability and applicability of this catalyst in Pd coupling reactions.
- Niknam, Esmaeil,Panahi, Farhad,Khalafi-Nezhad, Ali
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supporting information
(2021/01/12)
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- Bimetallic Ni/Cu mesoporous silica nanoparticles as an efficient and reusable catalyst for the Sonogashira cross-coupling reactions
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A bimetallic mesoporous system (Ni/Cu-MCM-41) has been developed and evaluated as an efficient catalyst for the Sonogashira cross-coupling reaction, under palladium-free conditions. In this new methodology, a wide range of aryl halides react with phenylacetylene to give the corresponding disubstituted alkynes in good yields. Moreover, the present catalytic system is desired because of its high efficiency, easy preparation, low cost, high activity, and good recyclability.
- Nasresfahani, Zahra,Kassaee, Mohamad Z.
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supporting information
(2021/02/12)
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- Design, synthesis, and biological evaluation of pyrimidine analogs as SecA inhibitors
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SecA, a key component of the bacterial Sec-dependent secretion pathway, is an attractive target for the development of new antimicrobial agents. We have previously reported pyrimidine analogs as SecA inhibitors. Herein, we report an extension of the earlier work in the synthesis and evaluation of a series of 15 5-cyanothiouracil derivatives as SecA inhibitors. All the compounds have been evaluated for their inhibition of SecA ATPase (EcSecAN68) and for their antimicrobial activity against Escherichia coli NR698 (a leaky mutant) and Bacillus anthracis Sterne. Twelve compounds showed IC50 of less than 6.3 μM when tested against EcSecAN68. In antimicrobial studies against E. coli NR698, six compounds showed MIC of 12.5 μM with three being less than 6.3 μM. Against B. anthracis Sterne, three compounds showed MIC of 6.3 μM.
- Bamba, Fante,Jin, Jinshan,Chaudhary, Arpana S.,Tai, Phang C.,Wang, Binghe
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p. 1334 - 1340
(2021/03/19)
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- Facile synthesis of Pd nanoparticles supported on a novel Schiff base modified chitosan-kaolin: Antibacterial and catalytic activities in Sonogashira coupling reaction
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The present work studies the Sonogashira coupling reaction (SCR) between aryl halides and acetylenes under aerobic conditions using the catalytic complex of Pd nanoparticles (NPs) supported on a novel Schiff base modified chitosan-kaolin (Pd NPs@CS-Kao) in ethanol solvent. The prepared catalyst was characterized by TEM, SEM, FT-IR, XRD, EDS, XPS, elemental mapping, and Raman analyses. The products were formed in high yields. At the end of the reaction, Pd NPs@CS-Kao can be filtered and reused for five consecutive cycles. The advantages of this catalytic process include simple methodology, high yields, and easy work-up. In addition, Pd NPs@CS-Kao exhibited effective antibacterial performance against E. coli gram-negative bacteria.
- Nasrollahzadeh, Mahmoud,Shafiei, Nasrin,Baran, Talat,Pakzad, Khatereh,Tahsili, Mohammad Reza,Baran, Nuray Y?lmaz,Shokouhimehr, Mohammadreza
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- Controlled Reduction of Nitriles by Sodium Hydride and Zinc Chloride
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A new protocol for the controlled reduction of nitriles to aldehydes was developed using a combination of sodium hydride and zinc chloride. The iminyl zinc intermediates derived from aromatic nitriles could be further functionalized with allylmetal nucleophiles to afford homoallylamines. As the method allows the reduction of various aliphatic and aromatic nitriles with a concise procedure under milder reaction conditions and exhibits wide functional group compatibility, it is well suited for use in various opportunities in chemical synthesis.
- Chiba, Shunsuke,Ong, Derek Yiren
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p. 1369 - 1378
(2020/04/27)
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- Ancillary ligands switch the activity of Ru–NHC-based oxidation precatalysts
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Herein we demonstrate how the inner-sphere coordinating ligands switch the activity of Ru–NHC-based oxidation precatalysts in the oxidative conversion of olefins to carbonyl compounds, with the help of a series of systematically varied imidazolydene-NHC (Im-NHC) and triazolydene-NHC (Tz-NHC)-based ruthenium(II)-complexes. It is shown that the catalytic activity of the para-cymene-containing precatalysts varies in the order of [(Tz-NHC)Ru(para-cymene)Cl]+ > [(Im-NHC)Ru(para-cymene)Cl]+, while the order of activity of the MeCN-containing precatalysts is found to be reversed, i.e., [(Im-NHC)Ru(MeCN)4]2+ > [(Tz-NHC)Ru(MeCN)4]2+. Along with the electronic influence of the NHC ligands, the effect of the lability of the para-cymene and MeCN ligands, and the overall charge of the complexes might be attributed toward such a switching of catalytic activity. This finding led to develop a new precatalyst with improved activity which was further utilized in selective oxidation of a series of styrene substrates containing other oxidation-sensitive functionalities.
- Gupta, Suraj K.,Mandal, Tanmoy,Gangber, Tejaswinee,Singh, Vivek,Choudhury, Joyanta
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supporting information
(2019/10/28)
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- (E)-N-(pyren-1-ylmethylene)benzenamine: efficient promoter for additive-free palladium catalyzed aerobic oxidative coupling of arylboronic acids and terminal alkynes
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Abstract: A highly productive protocol for the synthesis of internal alkynes by the carbon–carbon cross-coupling reactions of electronically different arylboronic acids with substituted phenylacetylenes was described by employing (E)-N-(pyren-1-ylmethylene)benzenamine with Pd(OAc)2. The influence of reaction parameters such as solvent, base and reaction temperature in this carbon–carbon cross-coupling reaction was also investigated. The substrate scope could be expanded to electron-poor alkynes, for which the conventional Sonogashira reaction gives poor yields. Moderate to excellent yield was obtained in the oxidative Sonogashira-type coupling reaction. Graphic abstract: [Figure not available: see fulltext.]
- Lakshmipraba, Jagadeesan,Prabhu, Rupesh Narayana,Dhayabaran, Victor Violet
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p. 3661 - 3669
(2020/04/21)
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- Anthracen-9-ylmethylene-(4-methoxyphenyl)amine: efficient promoter for silver-free palladium-catalyzed aerobic oxidative Sonogashira reactions
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An efficient protocol for the synthesis of unsymmetrical substituted diarylacetylenes by the C(sp2)–C(sp) cross-coupling reactions of substituted phenylacetylenes and electronically different arylboronic acids has been developed. Anthracen-9-ylmethylene-(4-methoxyphenyl)amine was employed as an efficient promoter in this Pd(OAc)2-catalyzed oxidative Sonogashira reaction in air in the absence of silver salt under optimized reaction conditions. The impact of reaction parameters such as solvent, base, reaction temperature and time in this silver-free aerobic oxidative Sonogashira cross-coupling reaction was also evaluated. Electron-deficient phenylacetylenes, which are sluggish coupling partners in the traditional Sonogashira reaction, underwent coupling in this protocol. The catalytic system is inexpensive, effortlessly attainable and highly flexible for functionalized phenylacetylenes and arylboronic acids. Graphic abstract: [Figure not available: see fulltext.].
- Lakshmipraba, Jagadeesan,Prabhu, Rupesh Narayana,Dhayabaran, Victor Violet
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p. 325 - 331
(2020/04/15)
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- Synthesis, antibacterial and anticancer activity, and docking study of aminoguanidines containing an alkynyl moiety
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Two series of aminoguanidines containing an alkynyl moiety were designed, synthesised, and screened for antibacterial and anticancer activities. Generally, the series 3a–3j with a 1,2-diphenylethyne exhibited better antibacterial activity than the other series (6a–6k) holding 1,4-diphenylbuta-1,3-diyne moiety antibacterial activity. Most compounds in series 3a–3j showed potent growth inhibition against the tested bacterial strains, with minimum inhibitory concentration (MIC) values in the range 0.25–8 μg/mL. Compound 3g demonstrated rapid and persistent bactericidal activity at 2 × MIC. The resistance study revealed that resistance of the tested bacteria towards 3g is not easily developed. Molecular docking studies revealed that compounds 3g and 6e bind strongly to the LpxC and FabH enzymes. Moreover, excellent activity of selected compounds against the growth of cancer cell lines A549 and SGC7901 was also observed, with IC50 values in the range 0.30–4.57 μg/mL. These findings indicate that compounds containing the aminoguanidine moiety are promising candidates for the development of new antibacterial and anticancer agents.
- Deng, Xianqing,Song, Mingxia
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p. 354 - 364
(2020/01/02)
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- A Co-Cu bimetallic magnetic nanocatalyst with synergistic and bifunctional performance for the base-free Suzuki, Sonogashira, and C-N cross-coupling reactions in water
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A novel magnetically recyclable bimetallic catalyst was prepared by anchoring imidazolium moiety and PEG chains on Fe3O4 NPs and named as Fe3O4?PEG/Cu-Co. It was found to be a powerful catalyst for the Sonogashira, Suzuki, and C-N cross-coupling reactions in water as a green solvent without the need for any external base. Fe3O4?PEG/Cu-Co was well characterized with FT-IR, FE-SEM, TEM, VSM, EDX, ICP, UV-visible, CV, and XPS analyses. Optimum ranges of parameters such as time, temperature, and amount of catalyst were investigated by Design-Expert 10.0.7 software for C-C Suzuki, Sonogashira, and C-N cross-coupling reactions to find the optimum conditions. The catalyst was compatible with a variety of aryl halides and N-arenes and gave favorable coupling products with good to high yields for all of them. Hot filtration and Hg poisoning tests involving the nanocatalyst revealed the stability, low metal leaching, and heterogeneous nature of the catalyst. Reaction mechanisms were proposed by study of the UV-visible spectra in situ as well as hydroquinone tests during the progress of reactions. In situ XPS analysis was also used to study the reaction mechanism. To prove the synergistic performance of Co and Cu in the catalyst, its various homologues were synthesized and applied to a model reaction separately, and then their catalytic activities were investigated. Finally, the catalyst could be recovered from the reaction mixture simply, and reused for several cycles with a minimum loss in catalytic activity and performance.
- Allahresani, Ali,Kazemnejadi, Milad,Nasseri, Mohammad Ali,Rezazadeh, Zinat
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p. 10645 - 10660
(2020/09/18)
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- Palladium(II) phthalocyanines efficiently promote phosphine-free Sonogashira cross-coupling reaction at room temperature
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Herein we report that exceptionally simple and inexpensive Pd(II) complexes of phthalocyanines efficiently catalyze direct formation of diphenylacetylenes at ambient conditions with low loading of catalyst (0.5 mol%). Results of this study demonstrate that terminal alkynes reacted mildly with p-substituted aryl bromides at room temperature under Pd and Cu-cocatalysis to give the corresponding phenylacetylenes in yields up to 98%. Also we have examined this catalyst in Sonogashira cross-coupling with aryl chlorides and it was very effective and this reaction at room temperature that there is no examples in recent articles. This protocol represents the first use of palladium phthalocyanine as homogeneous catalyst in the Pd/Cu-promoted Sonogashira reaction. The palladium(II) phthalocyanine complex is significantly more active in Sonogashira cross-coupling between aryl halides and terminal alkynes as compared with traditional catalysts because of absence of palladium black formation through agglomeration of metal particles and deactivation of catalyst.
- Platonova, Yana B.,Tomilova, Larisa G.,Volov, Alexander N.
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p. 224 - 228
(2020/09/17)
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- Sulphonic acid functionalized porphyrin anchored with a: Meso -substituted triazolium ionic liquid moiety: A heterogeneous photo-catalyst for metal/base free C-C cross-coupling and C-N/C-H activation using aryl chloride under visible light irradiation
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We report an easy process to synthesize sulphonic acid functionalized porphyrin, anchored with a meso-substituted triazolium ionic liquid moiety (SAFPTILM) for metal/base free C-C cross-coupling and C-N/C-H activation using aryl chloride under visible light irradiation. The acid strength has been measured based on the Hammett indicator. The SAFPTILM photocatalyst comprising 18 π-conjugated electronic systems with the chromophore substituents in the meso-position can provide rapid electronic conducting channels during photocatalysis under the irradiation of visible light. It was found that SAFPTILM is an efficient photocatalyst for the Heck, Sonogashira, Buchwald, Ullmann/Fittig coupling and C-H activation of phenols with different aryl chlorides in the absence of a base/noble metal, using 5 W LED (yellow) light under ambient conditions. The photocatalyst with low band gap (1.55 eV) comprising conjugation, favors coupling reaction of unactivated aryl chlorides, by easy excitation of electrons and transfer to the conjugated benzimidazolium based phenylenediamine support delaying the recombination of photoinduced electron-hole pairs.
- Bhansali, Karan,Raut, Subodh,Barange, Shital,Bhagat, Pundlik
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p. 19690 - 19712
(2020/12/04)
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- Efficient Sonogashira and A3 coupling reactions catalyzed by biosynthesized magnetic Fe3O4@Ni nanoparticles from Euphorbia maculata extract
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In this work, biosynthesized Fe3O4@Ni nanoparticles using Euphorbia maculata aqueous have been used as effective catalysts in the synthesis of 2,3-disubstituted benzo[b]furan derivatives using three component coupling of aldehydes, s
- Alinezhad, Heshmatollah,Pakzad, Khatereh,Nasrollahzadeh, Mahmoud
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- Preparation anchored Pd nanoparticles on glyoxal modified metal- organic framework for Sonogashira coupling reactions
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UIO-66-NH2-Gl?Pd nanocatalyst was successfully synthesized during post-synthetic modification (PSM) method and its application was investigated in the Sonogashira coupling reactions. Initially, UIO-66-NH2 was synthesized and identifi
- Alinezhad, Heshmatollah,Cheraghian, Mansoureh,Ghasemi, Shahram
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- Ni(acac)2/2,6-bis(diphenylphosphino)pyridine/CuI: A highly efficient palladium-free homogeneous catalyst for the Sonogashira cross-coupling reaction
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A highly efficient palladium-free homogeneous catalyst involving Ni(acac)2/2,6-bis(diphenylphosphino)pyridine ((Ph2P)2py)/CuI components was used for the Sonogashira cross-coupling reaction. The Sonogashira reaction was in
- Ataei, Ali,Daryanavard, Marzieh,Joshaghani, Mohammad,Rafiee, Ezzat
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- Pd-containing IL-based ordered nanostructured organosilica: A powerful and recoverable catalyst for Sonogashira reaction
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An IL-based ordered nanostructured organosilica supported palladium (Pd@ONO-IL) is synthesized and characterized. The Pd@ONO-IL was used as powerful nanocatalyst in the Sonogashira reaction that the corresponding products were obtained in high yield. The
- Shaker, Masoumeh,Elhamifar, Dawood
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supporting information
(2020/10/30)
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- Palladium(II) complexes containing sterically bulky O, N donor ligands: Synthesis, characterization and catalytic activity in the Suzuki-Miyaura and Sonogashira coupling reactions
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A new class of palladium(II)1-(arylazo)naphtholate complexes of the type [Pd(L1-4)2] containing sterically bulky O, N donor functionalized arylazo ligands has been synthesized. These palladium(II) complexes were characterized by elemental analysis and spectral (FT-IR, UV–Vis, 1H NMR and 13C NMR) studies. The molecular structure of the Palladium(II) complexes [Pd(L1)2] and [Pd(L2)2] were established by X-ray crystallography. These complexes were found to efficiently catalyze the Suzuki-Miyaura coupling of arylboronic acids and aryl halides, and the Sonogashira reaction of aryl halides and phenylacetylene in DMF and i-PrOH media to afford the corresponding C–C coupling products in high yields.
- Nandhini, Raja,Vijayan, Paranthaman,Venkatachalam, Galmari
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- Palladium anchored on guanidine-terminated magnetic dendrimer (G3-Gu-Pd): An efficient nano-sized catalyst for phosphorous-free Mizoroki-Heck and copper-free Sonogashira couplings in water
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In this research, a novel type of Fe3O4&at;silica-supported dendrimer capped by guanidine groups for immobilization of palladium was reported. This novel nano-sized catalyst was characterized by FTIR, TGA, XRD, FESEM, EDX, VSM, XPS and HRTEM methods. Enhanced catalytic activity of the prepared catalyst in Mizoroki-Heck and copper-free Sonogashira coupling reactions were evaluated in water as a green solvent. The influence of the various reaction parameters such as catalyst dosage, time and temperature on two mentioned C–C coupling reactions were studied. Results showed that the catalyst could be easily recovered by simple separation by an external magnet and reused for five cycles of recovery without considerable losing of its activity.
- Khalafi-Nezhad, Ali,Moaddeli, Ali,Niknam, Esmaeil
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- Designing Homogeneous Copper-Free Sonogashira Reaction through a Prism of Pd-Pd Transmetalation
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Simultaneous introduction of two different palladium (pre)catalysts, one tuned to promote oxidative addition to (hetero)aryl bromide and another to activate terminal alkyne substrate, leads to productive Pd-Pd transmetalation, subsequent reductive elimina
- Martek, Bruno A.,Gazvoda, Martin,Urankar, Damijana,Ko?mrlj, Janez
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supporting information
p. 4938 - 4943
(2020/05/19)
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- Synthesis and Redox Properties of Superbenzene Porphyrin Conjugates
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Superbenzene porphyrin conjugates find wide range of applications from nonlinear optical materials to semiconductors. Herein, we report the synthesis and characterization of 5,15-bis(3,5-di-tert-butylphenyl)-10,20-bis(pentaphenylphenyl)phenylporphyrin and its Zinc-metallated complex. Oxidative planarization of 5,15-bis(3,5-di-tert-butylphenyl)-10,20-bis(pentaphenylphenyl)phenylporphyrin and its metallated complex was carried out by using NOBF4 as an oxidizing agent. The formation of superbenzene porphyrin conjugates validates its Scholl type reactions. The laboratory-synthesized porphyrin conjugates were characterized experimentally using spectroscopic techniques such as 1H NMR, 13C NMR, electron spin resonance, and ultraviolet-visible spectroscopy for structural conformation. In addition, density functional theory calculations were carried out to validate the experimental results. The theoretical and experimental results show that the 4-(pentaphenylphenyl)phenyl ligand increases the stability, optical properties, and rate of planarization of synthesized porphyrins. The conjugates exhibited intense and distant electronic communication between two hexabenzocoronene sites, taking advantage of porphyrin as a ?-spacer. The ?-radical cation has also been found to be an intermediate in oxidative C-C bond formation. NICS calculations support such a conclusion.
- Nisa, Kharu,Khatri, Vikas,Kumar, Sharvan,Arora, Smriti,Ahmad, Sohail,Dandia, Anshu,Thirumal,Kashyap, Hemant K.,Chauhan, Shive M. S.
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supporting information
p. 16168 - 16177
(2020/11/13)
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- Pd/Cu-free Heck and Sonogashira coupling reactions applying cobalt nanoparticles supported on multifunctional porous organic hybrid
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A new heterogeneous cobalt catalyst has been synthesized by immobilizing Co species onto a nitrogen-rich porous organic polymer (Co@imine-POP). The heterogeneous catalyst synthesized was efficient in Heck and Sonogashira cross-coupling reactions in green media under mild reaction conditions without inert air and phase transfer agents. This phosphine-, copper-, and palladium-free catalyst was stable under the reaction conditions and could be reused for at least eight successive runs without a discernible decrease in its catalytic activity.
- Hajipour, Abdol R.,Khorsandi, Zahra
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- A Simple Nickel Catalyst Enabling an E-Selective Alkyne Semihydrogenation
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Stereoselective alkyne semihydrogenations are attractive approaches to alkenes, which are key building blocks for synthesis. With regards to the most atom-economic reducing agent dihydrogen (H2), only few catalysts for the challenging E-selective alkyne semihydrogenation have been disclosed, each with a unique substrate scope profile. Here, we show that a commercially available nickel catalyst facilitates the E-selective alkyne semihydrogenation of a wide variety of substituted internal alkynes. This results in a simple and broadly applicable overall protocol to stereoselectively access E-alkenes employing H2, which could serve as a general method for synthesis.
- Thiel, Niklas O.,Kaewmee, Benyapa,Tran Ngoc, Trung,Teichert, Johannes F.
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supporting information
p. 1597 - 1603
(2020/02/05)
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- Utilizing a copper-free Sonogashira reaction in the synthesis of the leukotriene a4 hydrolase modulator batatasin IV
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Batatasin IV is a dihydrostilbenoid isolated from Chinese yams which was shown to have inhibitory activities against plant growth. Later studies showed that this compound may exhibit anti-inflammatory properties by inhibiting the epoxide hydrolase activity of the leukotriene A4 hydrolase enzyme. To access the dihydrostilbenoid skeleton, a copper-free SPhos-mediated Sonogashira reaction was conceived and the substrate scope was explored. Our results indicate that the reaction can tolerate the presence of free alcohols, aldehydes, nitro groups, and anilinyl groups. However, a substituent with an acidic phenol or carboxylic acid group gave significantly lower yields. Next, a total synthesis of batatasin IV was accomplished in 16% overall yield incorporating the reported copper-free Sonogashira reaction. Finally, we show that batatasin IV inhibits the hydrolysis of alanine p-nitroanilide by leukotriene A4 hydrolase with an IC50 of 91.4 μM.
- Petruncio, Greg,Girgis, Michael,Moummi, Sanae,Jayatilake, Meth,Lee, Kyung Hyeon,Paige, Mikell
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supporting information
(2020/10/27)
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- Coordination Booster-Catalyst Assembly: Remote Osmium Outperforming Ruthenium in Boosting Catalytic Activity
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Presented herein is a set of bimetallic and trimetallic “coordination booster-catalyst” assemblies in which the coordination complexes [RuII(terpy)2] and [OsII(terpy)2] acted as boosters for enhancement of the catalytic activity of [RuII(NHC)(para-cymene)]-based catalytic site. The boosters accelerated the oxidative loss of para-cymene from the catalytic site to generate the active catalyst during the oxidation of alkenes and alkynes into corresponding aldehydes, ketones and diketones. It was found that the boosting efficiency of the [OsII(terpy)2] units was considerably higher than its congener [RuII(terpy)2] unit in these assemblies. Mechanistic studies were conducted to understand this unique improvement.
- Mandal, Tanmoy,Singh, Vivek,Choudhury, Joyanta
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supporting information
p. 4774 - 4779
(2019/11/11)
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- Preparation method of aryl alkyne catalyzed by visible light
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The invention discloses a simple and convenient method for directly synthesizing an aryl alkyne compound through photoredox catalysis. Aryl fluoroborate diazoate is used as an aryl free radical source, and different types of aryl alkyne are synthesized in situ through a decarboxylation process. A reaction has good functional group tolerability, and a simple domestic visible light source can be used for synthesizing the aryl alkyne of different functional groups under mild, neutral and transition-free metal reaction conditions.
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Paragraph 0050-0053
(2019/11/13)
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- Visible Light-Catalyzed Decarboxylative Alkynylation of Arenediazonium Salts with Alkynyl Carboxylic Acids: Direct Access to Aryl Alkynes by Organic Photoredox Catalysis
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A convenient method mediated by photoredox catalysis is developed for the direct construction of aryl alkynes. Readily available aromatic diazonium salts have been utilized as the aryl radical source to couple alkynyl carboxylic acids to feature the decarboxylative arylation. A wide range of substrates are amenable to this protocol with broad functional group tolerance, and diversely-functionalized aryl alkynes could be synthesized under mild, neutral and transition metal-free reaction conditions using visible light irradiation. Alongside synthetic sustainability associated with the photocatalytic and transition metal-free operation, another key point of this method is that the organic dye catalyst acts as an excited-state reductant, thus establishing the quenching cycle for radical addition and decarboxylative elimination. (Figure presented.).
- Yang, Liangfeng,Li, Haifeng,Du, Yijun,Cheng, Kai,Qi, Chenze
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p. 5030 - 5041
(2019/11/03)
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- A Drastic Effect of TEMPO in Zinc-Catalyzed Stannylation of Terminal Alkynes with Hydrostannanes via Dehydrogenation and Oxidative Dehydrogenation
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With a system consisting of a catalytic zinc Lewis acid, pyridine, and TEMPO in a nitrile medium, terminal alkynes coupled with HSnBu3, providing alkynylstannanes with structural diversity. The resulting alkynylstannane, without being isolated, could be directly used for Pd- and Cu-catalyzed transformations to deliver internal alkynes and more intricate tin-atom-containing molecules. Mechanistic studies indicated that TEMPOSnBu3 formed in situ from TEMPO and HSnBu3 works to stannylate the terminal alkyne in collaboration with the zinc catalyst, and that both of dehydrogenation and oxidative dehydrogenation processes are uniquely involved in a single reaction. (Figure presented.).
- Kai, Yuichi,Oku, Shinya,Sakurai, Kyoko,Tani, Tomohiro,Tsuchimoto, Teruhisa
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- Magnetic Cu–Schiff base complex with an ionic tail as a recyclable bifunctional catalyst for base/Pd-free Sonogashira coupling reaction
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Abstract: A Cu(II)–Schiff base complex containing imidazolium ionic phase was prepared and decorated on γ-Fe2O3 magnetic nanoparticles (γ-Fe2O3@Cu(II)IL-SB) and found to be an efficient catalyst for the Pd- and base-free Sonogashira coupling reaction. The heterogeneous catalyst was characterized by FTIR spectroscopy, UV–visible spectroscopy, FE-SEM, TEM, XRD spectroscopy, EDX spectroscopy, VSM, ICP spectroscopy, and atomic absorption spectroscopy. The coupling reactions were performed using the catalyst under mild and base-free conditions, and high-to-excellent yields were obtained for a variety of substrates. The catalyst demonstrates a dual-functionality arising from metal sites and imidazolium moieties and that the later plays a base role. Reusability and stability of γ-Fe2O3@Cu(II)IL-SB were studied several times, which can be reused up to eight consecutive runs with at least reduction in catalytic activity. Also, the mechanism of this bifunctional catalytic system was thoroughly investigated. Graphic abstract: A new and efficient method has been developed for the base- and Pd-free Sonogashira cross-coupling reactions of aryl halides with phenyl acetylene using a bifunctional γ-Fe2O3@Cu(II)IL-SB catalyst with imidazolium moiety under mild conditions[Figure not available: see fulltext.].
- Nasseri, Mohammad Ali,Rezazadeh, Zinat,Kazemnejadi, Milad,Allahresani, Ali
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p. 2693 - 2705
(2019/07/23)
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- The CuFe2O4@SiO2@ZrO2/SO42-/Cu nanoparticles: An efficient magnetically recyclable multifunctional Lewis/Br?nsted acid nanocatalyst for the ligand- and Pd-free Sonogashira cross-coupling reaction in water
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Herein, the synthesis and application of copper-incorporated sulfated zirconium oxide supported on CuFe2O4 NPs (CuFe2O4@SiO2@ZrO2/SO42-/Cu NPs) as a novel Lewis/Br?nsted acid nanocatalyst were studied for the Sonogashira C-C cross-coupling reaction. The fabricated CuFe2O4@SiO2@ZrO2/SO42-/Cu catalyst exhibited efficient activity for a large variety of aryl iodides/bromides and, most importantly, aryl chlorides in water and in the presence of NaOH as a base in short reaction times. The catalyst was fully characterized by FTIR, TG-DTG, VSM, XRD, EDX, FE-SEM and TEM analyses. A synergetic effect could be considered to have arisen from the various Lewis acid and Br?nsted acid sites present in the catalyst. The efficient incorporation of copper into zirconia provided a robust highly stable hybrid, which prevented any metal leaching, whether from the magnetite moiety and/or Cu sites in the reaction mixture. Moreover, the catalyst was successfully recovered from the mixture by a simple external magnet and reused for at least 9 consecutive runs. Zero metal leaching, stability, consistency with a variety of substrates, fast performance, cost-effectiveness, environmental friendliness, and preparation with accessible and cheap materials are some of the advantages and highlights of the current protocol.
- Nasseri, Mohammad Ali,Alavi, Seyyedeh Ameneh,Kazemnejadi, Milad,Allahresani, Ali
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p. 20749 - 20759
(2019/07/12)
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- A BODIPY-functionalized PdII photoredox catalyst for Sonogashira C-C cross-coupling reactions
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We report for the first time a BODIPY-functionalized dichloro(1,10-phenanthroline)palladium(ii) complex as an efficient photoredox catalyst for the Sonogashira C-C cross-coupling between phenylacetylene derivatives and iodobenzene derivatives with yields
- Dissanayake, Komadhie C.,Ebukuyo, Peters O.,Dhahir, Yasser J.,Wheeler, Kraig,He, Hongshan
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p. 4973 - 4976
(2019/05/21)
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- Sequentially Pd/Cu-Catalyzed Alkynylation-Oxidation Synthesis of 1,2-Diketones and Consecutive One-Pot Generation of Quinoxalines
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We report a simple and efficient one-pot synthesis of 1,2-diketones by concatenation of two Pd/Cu-catalyzed processes: Pd0/CuI-catalyzed Sonogashira coupling of terminal alkynes with aryl (pseudo)halides furnishes internal alkynes, which are directly transformed by PdII/CuII-catalyzed Wacker-type oxidation with DMSO and oxygen as dual oxidants to furnish 1,2-diketones. With this efficient, catalyst economical process, various aryl iodides and triflates are efficiently transformed in high yields into symmetrically and unsymmetrically substituted 1,2-diketones with various functional groups. This process can be readily extended to a consecutive one-pot synthesis of quinoxalines in a diversity-oriented fashion.
- Niesobski, Patrik,Martínez, Ivette Santana,Kustosz, Sebastian,Müller, Thomas J. J.
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supporting information
p. 5214 - 5218
(2019/07/31)
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- Synthesis and structural characterization of palladium(II) 2-(arylazo)naphtholate complexes and their catalytic activity in Suzuki and Sonogashira coupling reactions
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A family of five palladium(II) 2-(arylazo)naphtholate complexes, [PdCl(PPh3)(L)] (L = O, N-donor of bidentate 2-(arylazo)naphtholate ligands), have been synthesized and characterized by elemental analysis and spectral (FT-IR, UV–Vis, 1H-NMR and 13C-NMR) methods. Further, the catalytic efficiency of all the complexes have been investigated for Suzuki and Sonogashira coupling reaction of various aryl halides.
- Munusamy, Sathya,Muniyappan, Premkumar,Galmari, Venkatachalam
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p. 1910 - 1921
(2019/06/17)
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- Functionalized graphene oxide anchored to Ni complex as an effective recyclable heterogeneous catalyst for Sonogashira coupling reactions
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The Sonogashira cross coupling reaction is an applied method for preparation of diarylethyne compounds from readily available aryl halide derivatives and phenyl acetylene. The coupling reaction using nickel complex of N,N′-Bis(2-hydroxyethyl)ethylenediami
- Naeimi, Hossein,Kiani, Fatemeh
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- Palladium(II) octaalkoxy- and octaphenoxyphthalocyanines: Synthesis and evaluation as catalysts in the Sonogashira reaction
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Octaalkoxy- and octaphenoxysubstituted palladium phthalocyanines were used as a new family members of cross-coupling catalysts in the Sonogashira reaction. For the first time it was shown that terminal alkynes reacted mildly with p-substituted aryl bromides in gently conditions at room temperature under Pd and Cu-cocatalysis to give the corresponding phenylacetylenes. This protocol represents the use of palladium phthalocyanines as homogeneous catalysts in the Pd/Cu-promoted Sonogashira reaction.
- Platonova, Yana B.,Volov, Alexander N.,Tomilova, Larisa G.
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p. 222 - 227
(2019/04/17)
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- Recyclable cellulose-palladium nanoparticles for clean cross-coupling chemistry
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Cheap, recyclable, and robust cellulose-palladium nanoparticles were developed and fully characterized by FTIR, TEM, XPS, TGA, and NMR. The nanoparticles enabled cross-coupling chemistry in a truly general fashion i.e., Suzuki-Miyaura, Heck, Sonogashira, and C-H activation. Notably, all types of transformations were achieved with a single type of nanocatalyst. Complete recyclability of the catalyst and low traces of palladium in the product demonstrates the greenness of the protocol.
- Lu, Zhichao,Jasinski, Jacek B.,Handa, Sachin,Hammond, Gerald B.
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supporting information
p. 2748 - 2752
(2018/04/27)
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- Heterogenized Cu (II) salen complex grafted on graphene oxide nanosheets as a precursing catalyst for the Pd-free Sonogashira coupling
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Cu (II) salen complex immobilized on graphene oxide nanosheets [Cu (II) salen@GO] was synthesized with 3-chloropropyltrimethoxysilan as a linker and wholly characterized using various techniques like X-ray diffraction, Fourier-transform infrared, scanning electron microscopy/energy-dispersive X-ray spectroscopy, transmission electron microscopy, as well as atomic absorption spectroscopy (AAS). Cu (II) salen@GO as an effective heterogeneous catalyst has been investigated for the Sonogashira coupling reaction in dimethylsulfoxide with good to high yield (98%) in 4?hr at 110°C when the loading of Cu was 0.7?mmol?g?1 based on Cu element analysis by AAS. It was understood that heterogeneous catalyst was as active as its homogeneous analog, and presented good recoverability and no significant loss in activity within successive runs.
- Ghabdian, Mahdieh,Nasseri, Mohammad A.,Allahresani, Ali,Motavallizadehkakhky, Alireza
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- Transition-Metal-Free Highly Chemoselective and Stereoselective Reduction with Se/DMF/H2O System
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A novel metal-free reduction system, in which H2Se (or HSe-) produced in situ from Se/DMF/H2O acts as the active reducing species, has been developed. By using water as an inexpensive, safe, and environmentally friendly surrogate as the hydrogen donor, this new reduction system incorporating Se/DMF/H2O displayed high selectivity and good activity in the reduction of α,β-unsaturated ketones and alkynes. Therefore, this reduction system has great potential to be a general and practical reduction methodology in organic transformation.
- Li, Hong-Chen,An, Cui,Wu, Ge,Li, Guo-Xing,Huang, Xiao-Bo,Gao, Wen-Xia,Ding, Jin-Chang,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
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supporting information
p. 5573 - 5577
(2018/09/12)
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- Magnetically retrievable N-heterocyclic carbene-silver complex with wingtip ferrocenyl group for Sonogashira coupling
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A new magnetically retrievable N-heterocyclic carbene-silver complex with wingtip ferrocenyl group has been prepared by multi-step procedure. The formation of complex was confirmed on the basis of analytical techniques such as FT-IR, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), transmission electron microscopy (TEM) and VSM (vibrating sample magnetometer) analysis. The complex was successfully employed as an efficient heterogeneous catalyst for Sonogashira coupling reaction of aryl halides with terminal alkynes. The complex could be separated easily by applying external magnet. The reusability studies revealed that complex can be reused up to eight times without significant decrease in catalytic activity.
- Naikwade, Altafhusen,Bansode, Prakash,Rashinkar, Gajanan
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p. 112 - 122
(2018/05/03)
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- Development of highly electron-deficient and less sterically-hindered phosphine ligands possessing 1,3,5-triazinyl groups
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Highly electron-deficient and less sterically-hindered phosphine ligands with two or three 1,3,5-triazinyl groups on the phosphorus atoms have been synthesized and examined in transition metal-catalyzed reactions for the first time. Due to the lack of any hydrogens or substituents at ortho-positions of the 1,3,5-triazine towards the phosphorous atom, it is considered that the steric hindrance of the tris(triazinyl)phosphine ligand to a metal center is least among triarylphosphine ligands. In the Stille coupling of aryl iodides, these electron-poor phosphine ligands provided good product yields compared to hitherto well-known phosphine ligands.
- Abe, Kazumi,Kitamura, Masanori,Fujita, Hikaru,Kunishima, Munetaka
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- Efficient and green catalytic system incorporating new benzimidazolium salts for the Sonogashira cross-coupling reaction
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A number of novel benzimidazole salts were synthesized and their structures were determined using 1H NMR, 13C NMR and infrared spectroscopic techniques and elemental analysis. A catalyst system consisting of Pd(OAc)2 and copper nanoparticles in the presence of Cs2CO3 and incorporating the novel benzimidazole salts in poly(ethylene glycol) solvent significantly improved the yields of Sonogashira reactions between aryl halides and phenylacetylene under microwave irradiation in 10?min.
- Yavuz, Kemal,Kü?ükbay, Hasan
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- Ferrocenyl bisoxazoline as an efficient non-phosphorus ligand for palladium-catalyzed copper-free Sonogashira reaction in aqueous solution
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Pd(OAc)2-catalyzed Sonogashira coupling reactions of alkynes and a variety of aryl halides with 1,3-bis(5-ferrocenylisoxazoline-3-yl)benzene as an efficient non-phosphorus ligand under copper-free conditions are presented. The main advantages over previous methodologies include low catalyst loading (0.2 mol% Pd(OAc)2 and 0.4 mol% ferrocenyl bisoxazoline ligand are sufficient for these coupling reactions), less problematic reaction medium (water–dimethylformamide) and more convenient operation (no requirement for nitrogen protection).
- Yu, Shuyan,Wu, Jingxin,He, Xinwei,Shang, Yongjia
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