Bibliographies thématiques / Heteroatomic radical

Littérature scientifique sur le sujet « Heteroatomic radical »

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Publié le 25 mai 2024

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Articles de revues sur le sujet "Heteroatomic radical"

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Han, Yuxuan, et Xiuling Cui. « Copper-Catalyzed Enantioselective Radical Heteroatomic S—O Cross-Coupling ». Chinese Journal of Organic Chemistry 43, no 3 (2023) : 1201. http://dx.doi.org/10.6023/cjoc202300013.

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Linker, Torsten. « Addition of Heteroatom Radicals to endo-Glycals † ». Chemistry 2, no 1 (20 février 2020) : 80–92. http://dx.doi.org/10.3390/chemistry2010008.

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Radical reactions have found many applications in carbohydrate chemistry, especially in the construction of carbon–carbon bonds. The formation of carbon–heteroatom bonds has been less intensively studied. This mini-review will summarize the efforts to add heteroatom radicals to unsaturated carbohydrates like endo-glycals. Starting from early examples, developed more than 50 years ago, the importance of such reactions for carbohydrate chemistry and recent applications will be discussed. After a short introduction, the mini-review is divided in sub-chapters according to the heteroatoms halogen, nitrogen, phosphorus, and sulfur. The mechanisms of radical generation by chemical or photochemical processes and the subsequent reactions of the radicals at the 1-position will be discussed. This mini-review cannot cover all aspects of heteroatom-centered radicals in carbohydrate chemistry, but should provide an overview of the various strategies and future perspectives.
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Di Vaira, Massimo, Piero Stoppioni, Stefano Midollini, Franco Laschi et Piero Zanello. « H+ addition to the heteroatomic CoP3 cluster. Synthesis of the radical CoP3+ cluster and electrochemical study ». Polyhedron 10, no 18 (janvier 1991) : 2123–29. http://dx.doi.org/10.1016/s0277-5387(00)86131-8.

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Rhodes, Christopher J., Harry Morris, Hikmet Agirbas, Mark Standing et Yaming Zhang. « Distonic isomerisations of imine radical cations : aspects of the reactivity of heteroatomic subunits damaged by ionising radiation ». Journal of the Chemical Society, Perkin Transactions 2, no 6 (1998) : 1375–80. http://dx.doi.org/10.1039/a801066h.

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Taniguchi, Tsuyoshi. « Recent Advances in Reactions of Heteroatom-Centered Radicals ». Synthesis 49, no 16 (26 juillet 2017) : 3511–34. http://dx.doi.org/10.1055/s-0036-1588481.

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Heteroatom-centered radicals show versatile reactivity and offer useful synthetic methods in organic chemistry. The development of new approaches for forming heteroatom-centered radicals has recently expanded the practicality of radical chemistry for synthesis. This review focuses on recent advances in reactions of representative heteroatom-centered radicals.1 Introduction2 Group 17 Elements: Chlorine and Bromine Radicals3 Group 15 and Group 16 Elements3.1 Nitrogen- and Oxygen-Centered Radicals3.2 Phosphorus- and Sulfur-Centered Radicals3.3 Other Radicals4 Group 14 Elements: Silicon-Centered Radicals5 Group 13 Elements: Boron-Centered Radicals6 Conclusion
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Ogawa, Akiya, et Yuki Yamamoto. « Multicomponent Reactions between Heteroatom Compounds and Unsaturated Compounds in Radical Reactions ». Molecules 28, no 17 (30 août 2023) : 6356. http://dx.doi.org/10.3390/molecules28176356.

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In this mini-review, we present our concepts for designing multicomponent reactions with reference to a series of sequential radical reactions that we have developed. Radical reactions are well suited for the design of multicomponent reactions due to their high functional group tolerance and low solvent sensitivity. We have focused on the photolysis of interelement compounds with a heteroatom–heteroatom single bond, which readily generates heteroatom-centered radicals, and have studied the photoinduced radical addition of interelement compounds to unsaturated compounds. First, the background of multicomponent radical reactions is described, and basic concepts and methodology for the construction of multicomponent reactions are explained. Next, examples of multicomponent reactions involving two interelement compounds and one unsaturated compound are presented, as well as examples of multicomponent reactions involving one interelement compound and two unsaturated compounds. Furthermore, multicomponent reactions involving intramolecular cyclization processes are described.
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Renaud, Philippe, Alice Beauseigneur, Andrea Brecht-Forster, Barbara Becattini, Vincent Darmency, Sarkunam Kandhasamy, Florian Montermini et al. « Boron : A key element in radical reactions ». Pure and Applied Chemistry 79, no 2 (1 janvier 2007) : 223–33. http://dx.doi.org/10.1351/pac200779020223.

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Boron derivatives are becoming key reagents in radical chemistry. Here, we describe reactions where an organoboron derivative is used as a radical initiator, a chain-transfer reagent, and a radical precursor. For instance, B-alkylcatecholboranes, easily prepared by hydroboration of alkenes, represent a very efficient source of primary, secondary, and tertiary alkyl radicals. Their very high sensitivity toward oxygen- and heteroatom-centered radicals makes them particularly attractive for the development of radical chain processes such as conjugate addition, allylation, alkenylation, and alkynylation. Boron derivatives have also been used to develop an attractive new procedure for the reduction of radicals with alcohols and water. The selected examples presented here demonstrate that boron-containing reagents can efficiently replace tin derivatives in a wide range of radical reactions.
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Kawaguchi, Shin-ichi, Akiya Ogawa, Yuki Sato et Akihiro Nomoto. « Photoinduced Coupling Reaction of Diphenyl(2,4,6-trimethylbenzoyl)phosphine Oxide with Interelement Compounds : Application to the Synthesis of Thio- or Selenophosphinates ». Synthesis 49, no 16 (4 juillet 2017) : 3558–67. http://dx.doi.org/10.1055/s-0036-1588867.

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Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TMDPO) is a radical initiator widely used in the field of macromolecular chemistry, but not often applied in synthetic organic chemistry. We have focused­ on the use of TMDPO as a phosphorus source in reactions with different E – E compounds, where E – E represents a heteroatom–heteroatom­ bond, under photoirradiation. Interestingly, the cross-coupling reaction between TMDPO and disulfides or diselenides successfully affords thio- or selenophosphinates and thio- or selenoesters, respectively. The synthesis of series of thio- and selenophosphinates by this photoinduced cross-coupling reaction is demonstrated.
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Guo, Weisi, Qian Wang et Jieping Zhu. « Visible light photoredox-catalysed remote C–H functionalisation enabled by 1,5-hydrogen atom transfer (1,5-HAT) ». Chemical Society Reviews 50, no 13 (2021) : 7359–77. http://dx.doi.org/10.1039/d0cs00774a.

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The generation of heteroatom-centred radicals followed by intramolecular 1,5-HAT and functionalisation of the translocated carbon-centred radical is an efficient way to functionalize chemo- and regio-selectively the remote unactivated C(sp3)–H bond.
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Kubo, Takashi. « Synthesis, Physical Properties, and Reactivity of Stable, π-Conjugated, Carbon-Centered Radicals ». Molecules 24, no 4 (13 février 2019) : 665. http://dx.doi.org/10.3390/molecules24040665.

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Recently, long-lived, organic radical species have attracted much attention from chemists and material scientists because of their unique electronic properties derived from their magnetic spin and singly occupied molecular orbitals. Most stable and persistent organic radicals are heteroatom-centered radicals, whereas carbon-centered radicals are generally very reactive and therefore have had limited applications. Because the physical properties of carbon-centered radicals depend predominantly on the topology of the π-electron array, the development of new carbon-centered radicals is key to new basic molecular skeletons that promise novel and diverse applications of spin materials. This account summarizes our recent studies on the development of novel carbon-centered radicals, including phenalenyl, fluorenyl, and triarylmethyl radicals.
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Thèses sur le sujet "Heteroatomic radical"

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Wickenden, Jason. « Development of heteroatom radical based synthetic strategies ». Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45730.

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This thesis presents investigations of carbo- and heterocycle formation using radical relay cyclization reactions initiated by alkoxy radicals, cyclic imine formation using substoichiometric stannane and photodeoxygenation reactions involving benzotriazole-borane complexes. Chapter 1 describes our investigations and development of radical relay cyclization reactions initiated by alkoxy radicals that provided carbo- and heterocyclic compounds. Pairing N-alkoxyphthalimides as alkoxy radical precursors with the slow addition of radical initiator provided a wide range of carbocycles. Incorporation of functionality into the linear backbone provided substituted heterocyclic compounds in excellent yield. Chapter 2 describes the cyclization of aminyl radicals onto silyl enol ethers. The rate acceleration imparted by the silyl enol ether allowed for high yielding pyrrolidine formation. Investigations focused on an unexpected cyclic imine product that was observed in our previous studies. We sought to both optimize our conditions to provide this imine in the highest possible yield, and investigated the mechanism by which this imine product may be formed. Chapter 3 describes the development of a photodeoxygenation reaction using benzotriazole-borane complexes. The coordination of a benzotriazole ligand with commercially available borane-tetrahydrofuran provides the benzotriazole-borane complex as a bench stable white powder. DFT calculations suggested these benzotriazoleborane complexes could behave a radical chain deoxygenation reaction. Irradiation of a variety of xanthates provided the deoxygenated products in excellent yield. Furthermore, our work suggests that the benzotriazole ligand may be catalytic in these deoxygenation reactions.
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Nabokoff, Pierre. « Synthèses de précurseurs organiques de radicaux hétéroatomiques pour la préparation de matériaux hybrides ». Electronic Thesis or Diss., Aix-Marseille, 2020. http://theses.univ-amu.fr.lama.univ-amu.fr/201218_NABOKOFF_575sxytx526xlluw827l449jumhkc_TH.pdf.

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Cette étude a pour but d’explorer l’influence du nanoconfinement sur le comportement de substrats organiques incorporés dans des silices mésoporeuses. Ces travaux s’articulent en deux volets. Le premier est une étude sur l’efficacité de la réaction de fragmentation par voie photochimique ou thermique d’alcoxyamines confinées. Par comparaison avec une étude réalisée en solution, des mesures effectuées par spectroscopie RPE quantitative ont permis de montrer que l’efficacité de cette rupture n’est pas altérée par l’incorporation des précurseurs organiques dans une matrice de silice. Dans un second temps des matériaux hybrides organiques-inorganiques fonctionnalisés par des précurseurs diazèniques ont été synthétisés. Ces derniers sont capables, sous irradiation à 360 nm, de former des radicaux hétéroatomiques qui sont transitoires en solution mais persistants dans la silice. Différentes structures ont été synthétisées, notamment des matériaux fonctionnalisés par une paire de radicaux de nature différente, i.e. un radical aryloxyle disposé face à un radical arylsulfanyle. Des études RPE en onde continue et pulsée ont permis de mettre en évidence la grande durée de vie de ces espèces paramagnétiques confinées et de mesurer leurs temps de relaxation
The aim of this work was to investigate the influence of the nanocofinement on the behaviour of organic substrates embedded in mesoporous silicas. This research hinged on two parts. The first study focused on the efficiency of the fragmentation reaction of confined alkoxyamines, under thermal or photochemical activation. Thanks to the comparison with the very same reactions in solution, the quantitative EPR measurements showed that the confinement of organic precursors had no effect on the efficiency of these reactions. Secondly, organic-inorganic hybrid materials were synthesized. These mesoporous silicas were functionalized with diazene radical precursors. Upon 360 nm irradiation, they generated heteroatomic radicals. Different materials were prepared, including one which enabled to form a face-to-face pair of different radicals, i.e. an aryloxyl radical in front of an arylsulfanyl radical. Studies carried out by continuous and pulsed wave EPR enabled to highlight the high stability of these confined paramagnetic species and to measure their relaxation times
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Brulay, Guillaume. « Optimisation de la quantité de radicaux générés dans les silices hybrides mésoporeuses : synthèse, caractérisation, application ». Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0575.

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Le but de cette étude est de développer des silices mésoporeuses hybrides possédant une concentration en radicaux transitoires élevée pour permettre des application notamment en RMN-PDN. Tout d'abord, il a été montré que des rendements quantitatifs en centres paramagnétiques pouvaient être obtenus lors de réactions photochimiques unimoléculaires. La synthèse de nouveaux précurseurs ainsi qu'une optimisation des conditions de photolyse ont permis d'obtenir des silices fonctionnalisées par des radicaux transitoires avec des rendements de bons à quantitatifs. La différence de réactivité des divers précurseurs de radicaux a été rationalisée, une adéquation entre les mécanismes de fragmentation et les contraintes relatives à leur environnement dans les murs des silices est indispensable pour l'obtention de bons rendements. Ces systèmes polyradicalaires ont été caractérisés par spectroscopie RPE. Leur temps de vie élevé rend possible l'évaluation de ces nouveaux radicaux "persistant" en tant qu'agent de polarisation pour la RMN-PDN
The aim of this work was the development of hybrid mesoporous silicas composed with high concentration of embedded transient radicals in order to use them as polarizing agent in DNP-NMR. First of all, quantitative yield in paramagnetic centers were obtained from unimolecular processed carried out under photoirradiation. The synthesis and optimization of photolysis conditions allowed to obtain functionalized silicas by transient radicals from good to quantitative yields. The reactivity difference of radical precursors was rationalized by the fragmentation mechanism and environmental constraints inside the walls of the silica structure which provided high yields. Polyradical systems were characterized by EPR spectroscopy. High life-time allows the evaluation of these new "persistent" radical species as polarizing agent for DNP-NMR
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Buquoi, John Q. III. « Multicomponent Radical Reactions Incorporating Heteroatom-Carbon Bonds Via Polarity-Reversal Cascades ». The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574348050305556.

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Kayahara, Eiichi. « Studies on the Precision Control of Polymer Structure Based on Heteroatom-Mediated Living Radical Polymerization Reaction ». 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/142245.

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Ueno, Ryota. « Development of the Reactions of sp3-Carbon Radicals Adjacent to a Heteroatom with Aromatic Compoun ». 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225416.

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Tsai, Yi-Wen, et 蔡依雯. « Synthesis of heteroatom-doped carbon dots with tunable luminescence properties for bioimaging and free radical scavenging ». Thesis, 2019. http://ndltd.ncl.edu.tw/handle/yg29wt.

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碩士
國立臺灣科技大學
化學工程系
107
Herein, we combined with nano-synthesis technology and biomedical applications. We present an aqueous based facile microwave-assisted synthesis of carbon quantum dots, which has short synthesis time, low toxicity, water dispersibility and biocompatibility. These advantages are beneficial for biological application. The red, yellow, green and blue fluorescent carbon dots were successfully synthesized by adjusting the heteroatomic doping and changing the purification method. Furthermore, we applied these carbon dots for in vitro antioxidant activity and bioimaging. Part Ⅰ: Antioxidant activity of phosphorous and manganese element co-doped red magnetofluorescent carbon dots P-phenylenediamine was used as carbon precursor. Doping phosphorous (P) heteroatom into Cdots could enhance the quantum yield. Furthermore, doping manganese (Mn) could impart magnetic property to carbon dots. The red fluorescent carbon dots were successfully synthesized by one-pot microwave method. In this study, the application of antioxidant property for PMn@Cdots was carried out by using DPPH, •OH and O2-•, respectively. The result was compared with ascorbic acid and it showed that PMn@Cdots also have good antioxidant property. Furthermore, in the protective activity result of H2O2-induced cell death model, it was found that PMn@Cdots-HA could reduce intracellular ROS levels and protect cells from oxidative stress.
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Manna, Sabyasachi. « Construction of C-C Bonds by Photocatalysis via Radical Addition Cascade Cyclization (RACC) : Synthesis of Heteroatom-Containing Small Molecules ». Thesis, 2022. https://etd.iisc.ac.in/handle/2005/6050.

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The thesis presents photocatalytic methods for synthesizing small organic molecules at room temperature. The thesis is divided into four sections. Section A presents the general introduction to the thesis. Section B is presented as a single chapter, which describes an intramolecular ipso-arylative cyclization of aryl alkynoate with tricarbonyl compounds under photocatalytic conditions via radical addition cascade cyclization (RACC). The methodology could be extended to the arylpropiolamides and arylthioates as well. Section C is presented in two Chapters, Chapters 3 and 4. Chapter 3 describes a visible light-mediated difunctionalization of activated alkynes to form coumarin and spirolactones. The coumarins and spirolactones could be formed selectively by tuning the substituent present in the aryl alkynoate. The spirolactones synthesized in this method can be transformed into complex spirocyclic structures under a separate visible light-mediated reaction. Chapter 4 describes a visible light-mediated radical addition cascade cyclization (RACC) between maleimides and phenethylboronic acids to access fused tetrahydro-1H-benzo[e]isoindole-1,3(2H)-diones. The last section is presented as Chapter 5, which deals with a photocatalytic approach to the direct acylation of electron-deficient heteroarenes. The methodology could be used to synthesize biologically active small molecules.
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Rokade, Balaji Vasantrao. « Copper-Catalyzed Novel Oxidative Transformations : Construction of Carbon-Hetero Bonds ». Thesis, 2014. http://etd.iisc.ac.in/handle/2005/3479.

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The thesis entitled “Copper-Catalyzed Novel Oxidative Transformations: Construction of Carbon-Hetero Bonds” is divided into two main sections. Section A deals with the utility of azide as a nitrogen source for C-N bond formation, which is further divided into 4 chapters, and section B presents decarboxylative radical coupling reaction for C-heteroatom bond formation which is further divided in to two chapters. Section A Chapter 1 describes an approach for the direct synthesis of nitrile from the corresponding alcohols using azide as a nitrogen source. Nitrile functionality is a versatile and ubiquitous which occurs in a variety of natural products. Nitrile functionality can be easily transformed into a variety of functional groups and products such as aldehydes, ketones, acids, amines, amides and nitrogen-containing heterocycles, such as tetrazoles and oxazoles. In this chapter a successful attempt for developing a novel methodology to oxidize benzylic and cinnamyl alcohols to their corresponding nitriles in excellent yields has been described. This strategy uses DDQ as an oxidant and TMSN3 as a source of nitrogen in the presence of a catalytic amount of Cu(ClO4)2·6H2O. A few representative examples are highlighted in Scheme 1.1 Scheme 1. Oxidative conversion of alcohols to nitriles Second chapter represents a protocol for the synthesis of 1,5-disubstituted tetrazoles from the corresponding secondary alcohols. Among heterocyles, tetrazole and its derivatives are important class of nitrogen containing molecules. Due to their well-known biological activities as well as vast applications in pharmaceuticals and material science, they are potential targets for synthetic organic chemists. Therefore, a simple and user-friendly method for the synthesis of tetrazole is desirable. In this chapter, a mild and convenient method to synthesize 1,5-disubstituted tetrazoles using easily accessible secondary alcohols by employing TMSN3 as a nitrogen source is developed. This reaction is performed in the presence of a catalytic amount of Cu(ClO4)2·6H2O using DDQ as an oxidant under ambient conditions (Scheme 2).2 Scheme 2. Oxidative conversion of secondary alcohols to tetrazoles Third chapter presents a method for synthesizing amides from their corresponding secondary alcohols. Amide functionality is a crucial backbone in peptide chemistry, it also serve as an important precursor or intermediate for variety of organic transformations. In this contention, a mild and convenient method to synthesize amides using easily accessible secondary alcohols by employing TMSN3 as a nitrogen source is developed. This reaction is performed in the presence of a catalytic amount of Cu(ClO4)2·6H2O using DDQ as an oxidant under ambient conditions (Scheme 3).3 Scheme 3. Oxidative conversion of secondary alcohols to amides Additionally, the application of this methodology has also been revealed for the synthesis azides directly from their alcohols. Some of the representative examples are shown in the Scheme 4.3 Scheme 4. Direct conversion of alcohols to their azides. Fourth chapter describes highly chemoselective Schmidt reaction. The classical Schmidt reaction involves the formation of new carbon-nitrogen bonds in a reaction of a carbon-centred electrophile with hydrazoic acid followed by loss of nitrogen, which usually occurs via a rearrangement. It is well known that under the Schmidt reaction conditions, ketones and carboxylic acids are converted into their corresponding amides and amines respectively, whereas aldehydes furnish a mixture of formanilides and nitriles. In this chapter, Schmidt reaction of aldehydes to obtain their nitriles without formation of the corresponding formanilide is presented (Scheme 5).4 It was also observed that aromatic ketones and acids functionalities were intact under the reaction condition, unlike the conventional Schmidt reaction. Scheme 5. Highly chemoselective Schmidt reaction Section B It is divided into two chapters, describes a copper catalyzed decarboxylative radical coupling for the synthesis of vinyl sulfones and nitroolefins (Scheme 6). Scheme 6. General strategy for the second part First chapter narrates a strategy for synthesizing nitroolefins from the α,β-unsaturated carboxylic acids. Nitroolefins represent a unique class of nitro compounds, which have multifaceted utility in organic synthesis. They possess antibacterial, rodent-repelling, and antitumor activities. They serve as important intermediates in organic synthesis. Nitroolefins also react with a variety of nucleophiles, and their electron-deficient character renders them as a powerful dienophiles in Diels-Alder reactions. In our attempt to use the decarboxylative strategy, this chapter describes a method for the nitrodecarboxylation of substituted cinnamic acid derivatives to their corresponding nitroolefins. This nitrodecarboxylation reaction is performed using catalytic amount of CuCl in the presence of air using TBN as a nitrating source (Scheme 7).5 Besides, the reaction provides a useful method for the synthesis of β,β-disubstituted nitroolefin derivatives which are generally difficult to access from other conventional methods. Scheme 7. Decarboxylative nitration Second chapter presents a new protocol for the synthesis of vinyl sulfones from the α,β-unsaturated carboxylic acid. Vinyl sulfones are versatile building blocks, which find their utility as Michael acceptors and used in cycloaddition reactions. This functional group has also been shown to potently inhibit a variety of enzymatic processes, and thus provides unique properties for drug design and medicinal chemistry. Vinyl sulfones are prominent in medicinal chemistry owing to their wide presence in pharmaceutically active molecules, such as enzyme inhibitors and biological activity. In this chapter, we report a method for the construction of C-S bonds via ligand promoted decarboxylative radical sulfonylation of ,-unsaturated carboxylic acids to synthesize vinyl sulfones using Cu catalysis (Scheme 8).6 This is the first report for this particular conversion. Scheme 8. Decarboxylative sulfonation
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Rokade, Balaji Vasantrao. « Copper-Catalyzed Novel Oxidative Transformations : Construction of Carbon-Hetero Bonds ». Thesis, 2014. http://etd.iisc.ernet.in/2005/3479.

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The thesis entitled “Copper-Catalyzed Novel Oxidative Transformations: Construction of Carbon-Hetero Bonds” is divided into two main sections. Section A deals with the utility of azide as a nitrogen source for C-N bond formation, which is further divided into 4 chapters, and section B presents decarboxylative radical coupling reaction for C-heteroatom bond formation which is further divided in to two chapters. Section A Chapter 1 describes an approach for the direct synthesis of nitrile from the corresponding alcohols using azide as a nitrogen source. Nitrile functionality is a versatile and ubiquitous which occurs in a variety of natural products. Nitrile functionality can be easily transformed into a variety of functional groups and products such as aldehydes, ketones, acids, amines, amides and nitrogen-containing heterocycles, such as tetrazoles and oxazoles. In this chapter a successful attempt for developing a novel methodology to oxidize benzylic and cinnamyl alcohols to their corresponding nitriles in excellent yields has been described. This strategy uses DDQ as an oxidant and TMSN3 as a source of nitrogen in the presence of a catalytic amount of Cu(ClO4)2·6H2O. A few representative examples are highlighted in Scheme 1.1 Scheme 1. Oxidative conversion of alcohols to nitriles Second chapter represents a protocol for the synthesis of 1,5-disubstituted tetrazoles from the corresponding secondary alcohols. Among heterocyles, tetrazole and its derivatives are important class of nitrogen containing molecules. Due to their well-known biological activities as well as vast applications in pharmaceuticals and material science, they are potential targets for synthetic organic chemists. Therefore, a simple and user-friendly method for the synthesis of tetrazole is desirable. In this chapter, a mild and convenient method to synthesize 1,5-disubstituted tetrazoles using easily accessible secondary alcohols by employing TMSN3 as a nitrogen source is developed. This reaction is performed in the presence of a catalytic amount of Cu(ClO4)2·6H2O using DDQ as an oxidant under ambient conditions (Scheme 2).2 Scheme 2. Oxidative conversion of secondary alcohols to tetrazoles Third chapter presents a method for synthesizing amides from their corresponding secondary alcohols. Amide functionality is a crucial backbone in peptide chemistry, it also serve as an important precursor or intermediate for variety of organic transformations. In this contention, a mild and convenient method to synthesize amides using easily accessible secondary alcohols by employing TMSN3 as a nitrogen source is developed. This reaction is performed in the presence of a catalytic amount of Cu(ClO4)2·6H2O using DDQ as an oxidant under ambient conditions (Scheme 3).3 Scheme 3. Oxidative conversion of secondary alcohols to amides Additionally, the application of this methodology has also been revealed for the synthesis azides directly from their alcohols. Some of the representative examples are shown in the Scheme 4.3 Scheme 4. Direct conversion of alcohols to their azides. Fourth chapter describes highly chemoselective Schmidt reaction. The classical Schmidt reaction involves the formation of new carbon-nitrogen bonds in a reaction of a carbon-centred electrophile with hydrazoic acid followed by loss of nitrogen, which usually occurs via a rearrangement. It is well known that under the Schmidt reaction conditions, ketones and carboxylic acids are converted into their corresponding amides and amines respectively, whereas aldehydes furnish a mixture of formanilides and nitriles. In this chapter, Schmidt reaction of aldehydes to obtain their nitriles without formation of the corresponding formanilide is presented (Scheme 5).4 It was also observed that aromatic ketones and acids functionalities were intact under the reaction condition, unlike the conventional Schmidt reaction. Scheme 5. Highly chemoselective Schmidt reaction Section B It is divided into two chapters, describes a copper catalyzed decarboxylative radical coupling for the synthesis of vinyl sulfones and nitroolefins (Scheme 6). Scheme 6. General strategy for the second part First chapter narrates a strategy for synthesizing nitroolefins from the α,β-unsaturated carboxylic acids. Nitroolefins represent a unique class of nitro compounds, which have multifaceted utility in organic synthesis. They possess antibacterial, rodent-repelling, and antitumor activities. They serve as important intermediates in organic synthesis. Nitroolefins also react with a variety of nucleophiles, and their electron-deficient character renders them as a powerful dienophiles in Diels-Alder reactions. In our attempt to use the decarboxylative strategy, this chapter describes a method for the nitrodecarboxylation of substituted cinnamic acid derivatives to their corresponding nitroolefins. This nitrodecarboxylation reaction is performed using catalytic amount of CuCl in the presence of air using TBN as a nitrating source (Scheme 7).5 Besides, the reaction provides a useful method for the synthesis of β,β-disubstituted nitroolefin derivatives which are generally difficult to access from other conventional methods. Scheme 7. Decarboxylative nitration Second chapter presents a new protocol for the synthesis of vinyl sulfones from the α,β-unsaturated carboxylic acid. Vinyl sulfones are versatile building blocks, which find their utility as Michael acceptors and used in cycloaddition reactions. This functional group has also been shown to potently inhibit a variety of enzymatic processes, and thus provides unique properties for drug design and medicinal chemistry. Vinyl sulfones are prominent in medicinal chemistry owing to their wide presence in pharmaceutically active molecules, such as enzyme inhibitors and biological activity. In this chapter, we report a method for the construction of C-S bonds via ligand promoted decarboxylative radical sulfonylation of ,-unsaturated carboxylic acids to synthesize vinyl sulfones using Cu catalysis (Scheme 8).6 This is the first report for this particular conversion. Scheme 8. Decarboxylative sulfonation
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Livres sur le sujet "Heteroatomic radical"

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Fischer, H., dir. Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 1. Berlin, Heidelberg : Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-45824-1.

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Fischer, H., dir. Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0.

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Fischer, H., dir. Radicals Centered on Other Heteroatoms. Proton Transfer Equilibria. Berlin/Heidelberg : Springer-Verlag, 1997. http://dx.doi.org/10.1007/b52381.

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Fischer, H., dir. Radicals Centered on Heteroatoms with Z > ; 7 and Selected Anion Radicals II. Berlin/Heidelberg : Springer-Verlag, 1988. http://dx.doi.org/10.1007/b34135.

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Fischer, H., dir. Radicals Centered on Heteroatoms with Z > ; 7 and Selected Anion Radicals I. Berlin/Heidelberg : Springer-Verlag, 1988. http://dx.doi.org/10.1007/b86661.

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Davies, Alwyn G. Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Springer Berlin / Heidelberg, 2009.

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Dohrmann, J. K., et R. F. C. Claridge. Radicals Centered on Other Heteroatoms. Proton Transfer Equilibria (Numerical Data & Functional Relationships in Science & Technology). Springer, 1997.

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Howard, J. A., H. B. Stegmann, D. Klotz, G. Deuschle et P. Tordo. Radicals Centered on Heteroatoms with Z > 7 and Selected Anion Radicals I / Heteroatomzentrierte (Z > 7) Radikale und ausgewählte Anionradikale I (Numerical ... Relationships in Science & Technology). Springer, 1988.

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Radicals Centered on Heteroatoms with Z > 7 and Selected Anion Radicals II / Heteroatomzentrierte (Z > 7) Radikale und ausgewählte Anionradikale II (Numerical ... Relationships in Science & Technology). Springer, 1987.

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Chapitres de livres sur le sujet "Heteroatomic radical"

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Claridge, R. F. C. « 14 Radicals centered on other heteroatoms ». Dans Landolt-Börnstein - Group II Molecules and Radicals, 126. Berlin, Heidelberg : Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-45824-1_9.

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Fischer, H. « I General introduction ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 1–6. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_1.

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Davies, A. G. « 16.2.1.7 Tetrasubstituted 1,2-benzosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 93–107. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_10.

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Davies, A. G. « 16.2.1.8 Imino-1,2-benzosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 108–13. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_11.

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Davies, A. G. « 16.2.2.1 Unsubstituted 1,4-benzosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 114–15. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_12.

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Davies, A. G. « 16.2.2.2 Monosubstituted 1,4-benzosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 116–22. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_13.

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Davies, A. G. « 16.2.2.3 Disubstituted 1,4-benzosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 123–27. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_14.

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Davies, A. G. « 16.2.2.4 Trisubstituted 1,4-benzosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 128–31. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_15.

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Davies, A. G. « 16.2.2.5 Tetrasubstituted 1,4-benzosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 132–40. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_16.

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Davies, A. G. « 16.3 1,4-Naphthosemiquinones ». Dans Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions. Part 2, 141–52. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-87641-0_17.

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