- Suzuki-Miyaura cross-coupling and Heck-Mizoroki reactions catalysed by palladium on carbon nanofibres
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Platelet, tubular and herringbone carbon nanofibres were doped with Pd under various conditions. The catalysts were analysed for their Pd-content and as to the size distribution of the Pd particles. The Pd-doped carbon nanofibres were screened for their c
- Yamamoto, Kyoko,Thiemann, Thies
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Read Online
- Pd(II) complexes of a sterically bulky, benzannulated N-heterocyclic carbene and their catalytic activities in the Mizoroki-Heck reaction
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The bis(N,N′-diisopropylbenzimidazolin-2-ylidene)Pd(II) complexes trans-[PdBr2(iPr2-bimy)2] (trans-1) and trans-[PdI2(iPr2-bimy)2] (trans-2) have been prepared in good
- Han, Yuan,Huynh, Han Vinh,Koh, Lip Lin
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Read Online
- A Bis (BICAAC) Palladium(II) Complex: Synthesis and Implementation as Catalyst in Heck-Mizoroki and Suzuki-Miyaura Cross Coupling Reactions
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Carbenes are one of the most appealing, well-explored, and exciting ligands in modern chemistry due to their tunable stereoelectronic properties and a wide area of applications. A palladium complex (BICAAC)2PdCl2 with a recently discovered cyclic (alkyl)(amino)carbene having bicyclo[2.2.2] octane skeleton (BICAAC) was synthesized and characterized. The enhanced σ-donating and π-accepting ability of this carbene lend a hand to form a robust Pd-carbene bond, which allowed us to probe its reactivity as a precatalyst in Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions with low catalyst loading in open-air conditions. The diverse range of substrates was explored for both the cross-coupling reactions. To get a better understanding of the catalytic reactions, several analytical techniques such as field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and powder X-ray diffraction were employed in a conclusive manner.
- Chakrabortty, Soumyadeep,Kaur, Mandeep,Adhikari, Manu,Manar, Krishna K.,Singh, Sanjay
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supporting information
p. 6209 - 6217
(2021/05/06)
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- Palladium-Based Catalysts Supported by Unsymmetrical XYC–1 Type Pincer Ligands: C5 Arylation of Imidazoles and Synthesis of Octinoxate Utilizing the Mizoroki–Heck Reaction
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A series of new unsymmetrical (XYC–1 type) palladacycles (C1–C4) were designed and synthesized with simple anchoring ligands L1–4H (L1H = 2-((2-(4-methoxybenzylidene)-1-phenylhydrazinyl)methyl)pyridine, L2H = N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl)aniline, L3H = N,N-diethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl) aniline and L4H = 4-(4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono) methyl)phenyl)morpholine H = dissociable proton). Molecular structure of catalysts (C1–C4) were further established by single X-ray crystallographic studies. The catalytic performance of palladacycles (C1–C4) was explored with the direct Csp2–H arylation of imidazoles with aryl halide derivatives. These palladacycles were also applied for investigating of Mizoroki–Heck reactions with aryl halides and acrylate derivatives. During catalytic cycle in situ generated Pd(0) nanoparticles were characterized by XPS, SEM and TEM analysis and possible reaction pathways were proposed. The catalyst was employed as a pre-catalyst for the gram-scale synthesis of octinoxate, which is utilized as a UV-B sunscreen agent.
- Maji, Ankur,Singh, Ovender,Singh, Sain,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
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p. 1596 - 1611
(2020/04/29)
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- Monodentate phosphorus-coordinated palladium(II) complexes as new catalyst for Mizoroki-Heck reaction of aryl halides with electron-deficient olefins
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Four novel palladium(II) complexes coordinated by phosphorus atoms from both 3,5-disubstituted-1H-1,2,4-diazaphospholes in monodentate fashion were developed as efficient catalyst for the Mizoroki-Heck reaction of aryl halides with electron-deficient olefins. The coupling reaction of aryl halide bearig different functional groups with olefin derivatives took place and the corresponding products were isolated in good to excellent yields under optimal conditions. The procedure exhibits good functional group tolerance and wide substrate scope. This Mizoroki-Heck reaction was further achieved using Pd(OAc)2 and 3,5-di-isopropyl-1H-1,2,4-diazaphospholes as combined catalyst, which provide the convenient and alternative method in organic synthesis
- Zhao, Fang,Xin, Li,Zhang, Yingying,Jia, Xuefeng
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supporting information
p. 493 - 496
(2017/09/06)
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- Pd doped SiO2 nanoparticles: An efficient recyclable catalyst for Suzuki, Heck and Sonogashira reactions
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Palladium doped silica (Pd/SiO2) mesoporous material was synthesized via the sol-gel route using the P123 triblock copolymer as a structure directing agent. Pd/SiO2 was efficiently used as a catalyst for Suzuki, Heck and Sonogashira reactions under microwave irradiation. The catalyst exhibited high activity for all the coupling reactions and can be recycled nine times without a significant loss in its catalytic activity. This journal is the Partner Organisations 2014.
- Kotadia, Deepali A.,Patel, Urmila H.,Gandhi, Sahaj,Soni, Saurabh S.
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p. 32826 - 32833
(2014/08/18)
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- Ligand-free PdCl2-catalyzed heck reaction of arylboronic acids and olefins under reusable TBAB/H2O conditions
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A novel method was developed for Heck reaction of olefins and arylboronic acids using a ligand-free PdCl2 catalyst to afford the coupling products with excellent regio- and stereoselectivity. It is noteworthy that the PdCl2/CuSO4/K2CO3/TBAB/H 2O system can be recovered and used for three cycles directly. Georg Thieme Verlag Stuttgart, New York.
- Tang, Bo-Xiao,Fang, Xiao-Niu,Kuang, Ren-Yun,Hu, Rong-Hua,Wang, Ji-Wei,Li, Ping,Li, Xiao-Hang
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p. 2971 - 2976
(2013/11/06)
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- CATIONIC PALLADIUM COMPLEXES COMPRISING DIAMINO CARBENE LIGANDS AND THEIR USE IN CATALYSIS
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Cationic palladium catalysts comprising diamino carbene ligands, wherein the catalysts are of the formula [Pd(X)q(LBX)t(DC)]r+[Ym-]p or [Pd(X)q(LB)n(LBX)t(DC)]2a+[V-]u[Z2-]y, wherein DC is a diamino carbene ligand, X is an anionic ligand, LBX is a combined anionic and neutral ligand, and Y, V, and Z are non-coordinating anions. The compounds are useful in catalytic reactions, including cross-coupling reactions and hydroamination reactions. In particular, the catalysts are used in the following reactions: Suzuki-Miyaura coupling, Kumada coupling, Negishi coupling, Sonogashira coupling, Hartwig-Buchwald amination, and Heck-Mizoroki coupling.
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Page/Page column 32; 42
(2011/11/01)
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- Ce0.98Pd0.02O2-δ: Recyclable, ligand free palladium(II) catalyst for Heck reaction
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Palladium substituted in cerium dioxide in the form of a solid solution, Ce0.98Pd0.02O1.98 is a new heterogeneous catalyst which exhibits high activity and 100% trans-selectivity for the Heck reactions of aryl bromides including heteroaryls with olefins. The catalytic reactions work without any ligand. Nanocrystalline Ce0.98Pd 0.02O1.98 is prepared by solution combustion method and Pd is in +2 state. The catalyst can be separated, recovered and reused without significant loss in activity. Indian Academy of Sciences.
- Sanjaykumar,Mukri, Bhaskar Devu,Patil, Satish,Madras, Giridhar,Hegde
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experimental part
p. 47 - 54
(2012/02/05)
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- Palladium-catalyzed heck reaction of aryl chlorides under mild conditions promoted by organic ionic bases
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An efficient Pd-catalyzed Heck reaction of aryl chlorides with olefins under mild conditions is described. High yields of products were achieved with n-Bu4N+OAc- as base. Significantly, the temperature of the Heck reaction of diverse nonactivated aryl chlorides can be lowered to 80 °C. The new reaction system can also tolerate a wider range of olefins.
- Xu, Hua-Jian,Zhao, Yong-Qiang,Zhou, Xin-Feng
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experimental part
p. 8036 - 8041
(2011/12/02)
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- Dual inhibitors of inosine monophosphate dehydrogenase and histone deacetylase based on a cinnamic hydroxamic acid core structure
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Small molecules that act on multiple biological targets have been proposed to combat the drug resistance commonly observed for cancer chemotherapy. By combining the structural features of known inhibitors of inosine monophosphate dehydrogense (IMPDH) and
- Chen, Liqiang,Petrelli, Riccardo,Gao, Guangyao,Wilson, Daniel J.,McLean, Garrett T.,Jayaram, Hiremagalur N.,Sham, Yuk Y.,Pankiewicz, Krzysztof W.
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experimental part
p. 5950 - 5964
(2010/10/01)
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- N-heterocycle carbene (NHC)-ligated cyclopalladated N,N- dimethylbenzylamine: A highly active, practical and versatile catalyst for the Heck-Mizoroki reaction
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The wide dissemination of catalytic protocols in academic and industrial laboratories is facilitated by the development of catalysts that are not only highly active but also user-friendly, stable to moisture, air and long term storage and easy to prepare on a large scale. Herein we describe a protocol for the Heck-Mizoroki reaction mediated by cyclopalladN-dimethylbenzylamine (dmba) ligated ne, 1,3-bdot;HCl in refluxing acetonitrile in air in the presence of K2CO in iates the H bromides in reagent grade NMP at the 0.1-2 mol% range without the need for rigorous anhydrous techniques or a glovebox, and is active even in air. The catalyst is capable of achieving very high levels of catalytic activity (TON of up to 5.22 × 105) for the coupling of a deactivated arylbromide, p-bromoanisole, with tBu acrylate as a benchmark substrate pair. A wide range of aryl bromides, iodides and, for the first time with a NHC-Pd catalyst, a triflate was coupled with diverse acrylate derivatives (nitrile, tert-butyl ester and amides) and styrene derivatives. The use of excess (>2 equiv.) of the aryl bromide and tert-butyl acrylate leads to mixture of tert-butyl β,β-diarylacrylate and tert-butyl cinnamate derivatives depending on the substitution pattern of the aryl bromide. Electron rich m- and p-substituted arylbromides give the diarylated products exclusively, whereas electron-poor aryl bromides give predominantly mono-arylated products. For o-substituted aryl bromides, no doubly arylated products could be obtained under any conditions. Overall, the active catalyst (IMes-Pd) shows higher activity with electron-rich aryl halides, a marked difference compared with the more commonly used phosphane-Pd or non-ligated Pd catalysts.
- Peh, Guang-Rong,Kantchev, Eric Assen B.,Zhang, Chi,Ying, Jackie Y.
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supporting information; experimental part
p. 2110 - 2119
(2009/09/05)
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- ANTICANCER AGENTS
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The invention provides a compound of the invention, which is a compound of formula A-X-L-B, or a salt thereof, as well as compositions comprising a compound of the invention, and therapeutic methods that include the administration of a compound of the inv
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Page/Page column 14; 15-16
(2009/03/07)
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- An inexpensive and highly stable ligand 1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazine for Mizoroki-Heck and room temperature Suzuki-Miyaura cross-coupling reactions
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A bulky, inexpensive and simple bidentate ligand 1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazine (1) has been synthesized and characterized. The palladium catalyst was formed by combination of 1 with [Cl2Pd(COD)] in a ratio of 1:1, tested in the Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions. Coupling of a variety of aryl bromides with phenylboronic acid using methanol as solvent at room temperature, or at 60 °C, gave generally high yields of coupled products. Coupling of aryl chlorides with organoboron reagent at 110 °C in DMF afforded good yields of biaryls under aerobic conditions. This non-phosphorus, air and moisture stable catalyst also displays good activity for Mizoroki-Heck coupling reaction in methanol at 60 °C with various aryl chlorides and bromides.
- Mohanty, Sasmita,Suresh,Balakrishna, Maravanji S.,Mague, Joel. T.
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p. 240 - 247
(2008/09/16)
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- Imidazole and imidazoline derivatives as N-donor ligands for palladium-catalyzed Mizoroki-Heck reaction
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Imidazole and imidazoline (dihydroimidazole) derivatives can serve as efficient and simple Iigands for the palladium-catalyzed Mizoroki-Heck reaction. Among the imidazole and imidazoline derivatives in our investigations, the 2-methylimidazoline-palladium
- Haneda, Satoshi,Ueba, Chigusa,Eda, Kazuo,Hayashi, Masahiko
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p. 833 - 835
(2008/03/18)
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- Microwave-assisted copper-catalyzed heck reaction in PEG solvent
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A catalytic system made of a copper salt, potassium carbonate and PEG 3400 was developed to perform a Heck arylation under microwave activation. Copper iodide gave the best results in a short reaction time (30 min) and various substituted tert-butyl cinna
- Declerck, Valérie,Martinez, Jean,Lamaty, Frédéric
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p. 3029 - 3032
(2008/02/13)
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- Solvent-controlled selective synthesis of a trans-configured benzimidazoline-2-ylidene palladium(II) complex and investigations of its Heck-type catalytic activity
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Reaction of N,N′-dimethylbenzimidazolyl iodide (A) with Pd(OAc) 2 in DMSO gives selectively trans-bis(N,N′- dimethylbenzimidazoline-2-ylidene) palladium(II) diiodide (trans-2) in 77% yield. The selective formation of the trans-coordination isom
- Huynh, Han Vinh,Ho, Joanne Hui Hui,Neo, Tiong Cheng,Koh, Lip Lin
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p. 3854 - 3860
(2007/10/03)
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- Discovery and optimization of non-steroidal FXR agonists from natural product-like libraries.
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The efficient regulation of cholesterol biosynthesis, metabolism, acquisition, and transport is an essential component of lipid homeostasis. The farnesoid X receptor (FXR) is a transcriptional sensor for bile acids, the primary product of cholesterol metabolism. Accordingly, the development of potent, selective, small molecule agonists, partial agonists, and antagonists of FXR would be an important step in further deconvoluting FXR physiology. Herein, we describe the development of four novel classes of potent FXR activators originating from natural product-like libraries. Initial screening of a 10,000-membered, diversity-orientated library of benzopyran containing small molecules for FXR activation utilizing a cell-based reporter assay led to the identification of several lead compounds possessing low micromolar activity (EC50's = 5-10 microM). These compounds were systematically optimized employing parallel solution-phase synthesis and solid-phase synthesis to provide four classes of compounds that potently activate FXR. Two series of compounds, bearing stilbene or biaryl moieties, contain members that are the most potent FXR agonists reported to date in cell-based assays. These compounds may find future utility as chemical tools in studies aimed at further defining the physiological role of FXR and discovering potential therapeutic agents for the treatment of diseases linked to cholesterol and bile acid metabolism and homeostasis.
- Nicolaou,Evans, Ronald M,Roecker,Hughes, Robert,Downes, Michael,Pfefferkorn, Jeffery A
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p. 908 - 920
(2007/10/03)
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- Asymmetric synthesis of homochiral differentially protected bis-β-amino acid scaffolds
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A strategy for the asymmetric synthesis of homochiral [(R,R)- or (S,S)-], or meso-(R,S) bis-β-amino acid scaffolds, formally resulting from the stepwise conjugate addition of two differentially protected homochiral lithium amides to two α,β-unsaturated esters attached to a central arene, is demonstrated. Further manipulation enables the efficient synthesis of orthogonally protected pseudo-meso or pseudo-C2 symmetric scaffolds via selective N-benzyl or N-allyl deprotection, enabling regio-, stereo- and chemoselective functionalisation.
- Bull, Steven D,Davies, Stephen G,Roberts, Paul M,Savory, Edward D,Smith, Andrew D
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p. 4629 - 4642
(2007/10/03)
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- Mild and efficient aryl-alkenyl coupling via Pd(II) catalysis in the presence of oxygen or Cu(II) oxidants
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We report herein a mild and efficient method for carbon-carbon bond formation between aryl stannanes and olefins via Pd(II) catalysis in the presence of oxygen or Cu(II) oxidants as a reoxidant. The process allows reactions between various olefins and aryl stannanes of varying electron density. Coupling methods under these oxidation conditions are comparatively described, and the benefits and limitations are also discussed.
- Parrish, Jay P.,Jung, Young Chun,Shin, Seung Il,Jung, Kyung Woon
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p. 7127 - 7130
(2007/10/03)
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- Highly Efficient Heck Reactions of Aryl Bromides with n-Butyl Acrylate Mediated by a Palladium/Phosphine-Imidazolium Salt System
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matrix presented A new phosphine-imidazolium salt, L·HBr (1, L = (1-ethylenediphenylphosphino-3-(mesityl))imidazol-2-ylidene), has been prepared. A combination of 0.5 mol % of Pd(dba)2 and 0.5 mol % of L·HBr in the presence of 2 equiv of Cssub
- Yang, Chuluo,Lee, Hon Man,Nolan, Steven P.
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p. 1511 - 1514
(2007/10/03)
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- 2-(N'-aralkylidenehydrazino)adenosines: Potent and selective coronary vasodilators
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This study aimed at the development of 2-(N'- aralkylidenehydrazino)adenosines as coronary vasodilators. The reaction of aromatic aldehydes or ketones with 2-hydrazinoadenosine in refluxing methanol formed the target compounds 2-27 as crystalline products
- Niiya,Thompson,Silvia,Olsson
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p. 4562 - 4566
(2007/10/02)
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