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Palladium Catalysed Reaction

Leleti Rajender Reddy, Sharadsrikar Kotturi, Yogesh Waman, Vudem Ravinder Reddy, Chirag Patel, Ajinath Kobarne, Sasikumar Kuttappan
A highly efficient method of visible light mediated Ni(II)-catalyzed photoredox N-arylation of Cbz-amines/Boc-amines with aryl electrophiles at room temperature is reported. The methodology provides a common access to a wide variety of N-aromatic and N-heteroaromatic carbamate products that find use in the synthesis of several biologically active molecules and provides a distinct advantage over traditional palladium-catalyzed Buchwald reaction.
October 18, 2018: Journal of Organic Chemistry
Julien Pedron, Clotilde Boudot, Sandra Bourgeade-Delmas, Alix Sournia-Saquet, Lucie Paloque, Maryam Rastegari, Mansour Abdoulaye, Hussein El-Kashef, Colin Bonduelle, Geneviève Pratviel, Susan Wyllie, Alan H Fairlamb, Bertrand Courtioux, Pierre Verhaeghe, Alexis Valentin
An antikinetoplastid pharmacomodulation study at position 3 of the recently described hit molecule 3-bromo-8-nitroquinolin-2(1H)-one was conducted. Twenty-four derivatives were synthesised using the Suzuki-Miyaura cross-coupling reaction and evaluated in vitro on both Leishmania infantum axenic amastigotes and Trypanosoma brucei brucei trypomastigotes. Introduction of a para-carboxyphenyl group at position 3 of the scaffold led to the selective antitrypanosomal hit molecule 3-(4-carboxyphenyl)-8-nitroquinolin-2(1H)-one (21) with a lower reduction potential (-0...
September 17, 2018: ChemMedChem
Raysa Khan, Sarote Boonseng, Paul D Kemmitt, Robert Felix, Simon J Coles, Graham J Tizzard, Gareth Williams, Olivia Simmonds, Jessica-Lily Harvey, John Atack, Hazel Cox, John Spencer
5-Phenyl-1,3-dihydro- 2H -1,4-benzodiazepin-2-ones react under palladium- and visible light photoredox catalysis, in refluxing methanol, with aryldiazonium salts to afford the respective 5-(2-arylphenyl) analogues. With 2- or 4-fluorobenzenediazonium derivatives, both fluoroaryl- and methoxyaryl- products were obtained, the latter resulting from a SN Ar on the fluorobenzenediazonium salt ("nuisance effect"). A computational DFT analysis of the palladium-catalysed and the palladium/ruthenium-photocalysed mechanism for the functionalization of benzodiazepines indicated that, in the presence of the photocatalyst, the reaction proceeds via a low-energy SET pathway avoiding the high-energy oxidative addition step in the palladium-only catalysed reaction pathway...
September 18, 2017: Advanced Synthesis & Catalysis
Philani P Mpungose, Zanele P Vundla, Glenn E M Maguire, Holger B Friedrich
In the last 30 years, C⁻C cross coupling reactions have become a reliable technique in organic synthesis due their versatility and efficiency. While drawbacks have been experienced on an industrial scale with the use of homogenous systems, many attempts have been made to facilitate a heterogeneous renaissance. Thus, this review gives an overview of the current status of the use of heterogeneous catalysts particularly in Suzuki and Heck reactions. Most recent developments focus on palladium immobilised or supported on various classes of supports, thus this review highlights and discuss contributions of the last decade...
July 10, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Francesco Messa, Serena Perrone, Martina Capua, Francesco Tolomeo, Luigino Troisi, Vito Capriati, Antonio Salomone
A palladium-catalysed aminocarbonylation of (hetero)aryl iodides has, for the first time, been accomplished in deep eutectic solvents as environmentally benign and recyclable media, under mild conditions. The reactions proceeded with a good substrate scope, and a variety of amides have been synthesized in yields up to 98%.
July 17, 2018: Chemical Communications: Chem Comm
Zupeng Chen, Evgeniya Vorobyeva, Sharon Mitchell, Edvin Fako, Manuel A Ortuño, Núria López, Sean M Collins, Paul A Midgley, Sylvia Richard, Gianvito Vilé, Javier Pérez-Ramírez
Palladium-catalysed cross-coupling reactions, central tools in fine-chemical synthesis, predominantly employ soluble metal complexes despite recognized challenges with product purification and catalyst reusability1-3 . Attempts to tether these homogeneous catalysts on insoluble carriers have been thwarted by suboptimal stability, which leads to a progressively worsening performance due to metal leaching or clustering4 . The alternative application of supported Pd nanoparticles has faced limitations because of insufficient activity under the mild conditions required to avoid thermal degradation of the substrates or products...
August 2018: Nature Nanotechnology
Mayukh Deb, Susanta Hazra, Ajay Gupta, Anil J Elias
A palladium catalysed methodology for mono-selective oxidative aroylation of ferrocene has been achieved. 10 mol% of Pd(OAc)2 was used as the catalyst for this radical aroylation reaction using O-methyl-oxime as the directing group. tert-Butyl hydroperoxide was used as an oxidant and both aldehydes and alcohols were used as acyl-equivalents. The protocol has been extended to aryl, heteroaryl and sterically hindered aroylating agents. Acidic-hydrolysis with 6(N) HCl of the directing group resulted in unsymmetrically substituted ketone derivatives of ferrocene, which have not been achieved otherwise...
May 29, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Hirokazu Tsukamoto, Kazuya Ito, Takayuki Doi
Multi-substituted dihydrofurans were obtained from a palladium-catalysed coupling reaction between 2,3-alkadienols and ketones bearing an electron-withdrawing group at the α-position. Methanol as a solvent was essential for the initial dehydrative substitution to suppress the competitive hydroalkylation of the diene moiety. The substitution would be followed by intramolecular hydroalkoxylation under the same catalysis.
May 15, 2018: Chemical Communications: Chem Comm
Bowen Lei, Xiaojiao Wang, Lifang Ma, Yan Li, Ziyuan Li
An iron-catalysed intermolecular vicinal aminoazidation of alkenes, using N-fluorobenzenesulfonimide (NFSI) and trimethylsilyl azide (TMSN3) as the imidating and azidating reagents, respectively, is described, which could potentially provide a valuable route toward diverse vicinal diamine derivatives of great significance in medicinal chemistry and organic synthesis. Such iron-catalysed aminative bisfunctionalization of alkenes with NFSI has not been reported yet. Comparing to previously employed copper or palladium catalysts, the iron catalyst, FeCl2, was demonstrated to be a good alternative for its comparable efficiency and broad alkene scope...
May 2, 2018: Organic & Biomolecular Chemistry
Xuekai Zhang, Gang Lu, Meng Sun, Madhu Mahankali, Yanfei Ma, Mingming Zhang, Wangde Hua, Yuting Hu, Qingbing Wang, Jinghuo Chen, Gang He, Xiangbing Qi, Weijun Shen, Peng Liu, Gong Chen
New methods capable of effecting cyclization, and forming novel three-dimensional structures while maintaining favourable physicochemical properties are needed to facilitate the development of cyclic peptide-based drugs that can engage challenging biological targets, such as protein-protein interactions. Here, we report a highly efficient and generally applicable strategy for constructing new types of peptide macrocycles using palladium-catalysed intramolecular C(sp3 )-H arylation reactions. Easily accessible linear peptide precursors of simple and versatile design can be selectively cyclized at the side chains of either aromatic or modified non-aromatic amino acid units to form various cyclophane-braced peptide cycles...
May 2018: Nature Chemistry
Anna Isakova, Billy J Murdoch, Katarina Novakovic
The oscillatory palladium-catalysed carbonylation reaction opens new horizons for applications in smart materials due to the versatility of its conditions and substrates, as well as the adjustability of amplitude and period of pH oscillations. A variety of viable substrates have been demonstrated, including polymeric alkyne-terminated substrates. However, so far, there have not been any reports of polymer-based palladium catalysts in oscillatory mode. In this paper, we demonstrate pH oscillations in various systems, using commercially available palladium acetate, a triphenylphosphine palladium acetate complex and a polymer-bound palladium catalyst...
April 4, 2018: Physical Chemistry Chemical Physics: PCCP
Qianqian Guan, Qi Sun, Lixian Wen, Zhenggen Zha, Yu Yang, Zhiyong Wang
An efficient synthesis of benzimidazoles was developed by virtue of a recycled palladium catalyzed hydrogen transfer. The reaction can be carried out smoothly under mild conditions to give rise to a variety of benzimidazoles with good to excellent yields. The palladium catalyst could be recovered easily and reused six times with great catalytic activity.
March 28, 2018: Organic & Biomolecular Chemistry
Stefano Parisotto, Lorenzo Palagi, Cristina Prandi, Annamaria Deagostino
Palladium(0)-catalysed hydro-alkylation or -alkenylation of alkoxyallenes with N-tosylhydrazones gives direct access to conjugated and skipped 1-alkoxydienes with high efficiency and excellent functional-group compatibility. The reaction is proposed to involve the in situ-formed t-butanol as proton source in the key step of the allylpalladium(II) species generation. Moreover, lithium iodide or iodobenzene are employed as an unprecedented iodide (I- ) reservoir to sustain the catalytic cycle.
April 11, 2018: Chemistry: a European Journal
Kumiko Yamamoto, Jiakun Li, Jeffrey A O Garber, Julian D Rolfes, Gregory B Boursalian, Jannik C Borghs, Christophe Genicot, Jérôme Jacq, Maurice van Gastel, Frank Neese, Tobias Ritter
Aryl fluorides are widely used in the pharmaceutical and agrochemical industries, and recent advances have enabled their synthesis through the conversion of various functional groups. However, there is a lack of general methods for direct aromatic carbon-hydrogen (C-H) fluorination. Conventional methods require the use of either strong fluorinating reagents, which are often unselective and difficult to handle, such as elemental fluorine, or less reactive reagents that attack only the most activated arenes, which reduces the substrate scope...
February 21, 2018: Nature
Daniel G Kohler, Samuel N Gockel, Jennifer L Kennemur, Peter J Waller, Kami L Hull
In recent years, the synthesis of amines and other nitrogen-containing motifs has been a major area of research in organic chemistry because they are widely represented in biologically active molecules. Current strategies rely on a multistep approach and require one reactant to be activated prior to the carbon-nitrogen bond formation. This leads to a reaction inefficiency and functional group intolerance. As such, a general approach to the synthesis of nitrogen-containing compounds from readily available and benign starting materials is highly desirable...
March 2018: Nature Chemistry
Itzel Guerrero-Ríos, Alfonso H Ortiz-Ramírez, Piet W N M van Leeuwen, Erika Martin
The asymmetric allylic alkylation of rac-1,3-diphenyl-3-acetoxyprop-1-ene (I) catalysed by palladium and diverse phosphorus containing ligands [(S)-BINAP, (R,R)-Chiraphite and (R,R)-Et-Duphos] in an ionic liquid [HDBU][OAc] was successfully performed, achieving full conversions and up to 96% ee of the (S)-product when (R,R)-Et-Duphos was used as a ligand. The reaction could be performed using an equimolar amount of substrate, malonate and base DBU, in which case the total products sum to the desired alkylated product and the ionic pair [HDBU][OAc]; this system thus produces its own IL solvent as the only co-product...
March 12, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
R Garrison Kinney, Jevgenijs Tjutrins, Gerardo M Torres, Nina Jiabao Liu, Omkar Kulkarni, Bruce A Arndtsen
The development of metal-catalysed methods to functionalize inert C-H bonds has become a dominant research theme in the past decade as an approach to efficient synthesis. However, the incorporation of carbon monoxide into such reactions to form valuable ketones has to date proved a challenge, despite its potential as a straightforward and green alternative to Friedel-Crafts reactions. Here we describe a new approach to palladium-catalysed C-H bond functionalization in which carbon monoxide is used to drive the generation of high-energy electrophiles...
February 2018: Nature Chemistry
Amrita Mondal, Priyanka Kundu, Moumita Jash, Chinmay Chowdhury
An efficient method has been developed for the stereoselective synthesis of 4-(diarylmethylidene)-3,4-dihydroisoquinolin-1(2H)-ones 7 through tandem Heck-Suzuki coupling at rt using easily available substrates. DBU easily converted the exocyclic double bond of these compounds to endo, furnishing 8 and 9. Reduction of the carbonyl group of 7 was smoothly carried out with borane dimethyl sulphide. Subsequent treatment with KOt Bu provided an easy access to 4-substituted isoquinolines 10a if carried out in refluxing 1,4-dioxane, while reaction in DMF at rt led to the incorporation of an extra hydroxyl group at the benzylic position of the isoquinolines to give 10b...
February 7, 2018: Organic & Biomolecular Chemistry
Farah Benyettou, Laurence Motte, Hassan Traboulsi, Javed Mazher, Renu Pasricha, John-Carl Olsen, Ali Trabolsi, Erwan Guenin
Cucurbit[7]uril modified iron oxide nanoparticles (CB[7]NPs) were loaded with palladium to form nano-catalysts (Pd@CB[7]NPs) that, with microwave heating, catalysed Suzuki-Miyaura, Sonogashira, and Mizoroki-Heck cross-coupling reactions. Reactions were run in environmentally benign 1:1 ethanol/water solvent under convenient aerobic conditions. In a preliminary screening, conversions and yields were uniformly high with turn over frequencies (TOF) ranging from 64 to 7360 h-1 . The nano-catalysts could be recovered with a magnet and reused several times (6 times for Suzuki-Miayura reaction) without loss of activity...
February 16, 2018: Chemistry: a European Journal
Peng Wang, Pritha Verma, Guoqin Xia, Jun Shi, Jennifer X Qiao, Shiwei Tao, Peter T W Cheng, Michael A Poss, Marcus E Farmer, Kap-Sun Yeung, Jin-Quan Yu
The directed activation of carbon-hydrogen bonds (C-H) is important in the development of synthetically useful reactions, owing to the proximity-induced reactivity and selectivity that is enabled by coordinating functional groups. Palladium-catalysed non-directed C-H activation could potentially enable further useful reactions, because it can reach more distant sites and be applied to substrates that do not contain appropriate directing groups; however, its development has faced substantial challenges associated with the lack of sufficiently active palladium catalysts...
November 22, 2017: Nature
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