Bibliographies thématiques / C heteroatom / Articles de revues

Articles de revues sur le sujet « C heteroatom »

Pour voir les autres types de publications sur ce sujet consultez le lien suivant : C heteroatom.
Auteur : Grafiati
Publié le 18 mai 2024

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les 50 meilleurs articles de revues pour votre recherche sur le sujet « C heteroatom ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Parcourez les articles de revues sur diverses disciplines et organisez correctement votre bibliographie.

1

Wang, Jia-Qi, Zhen-Yu Zuo et Wei He. « Recent Advances of Green Catalytic System I2/DMSO in C–C and C–Heteroatom Bonds Formation ». Catalysts 12, no 8 (26 juillet 2022) : 821. http://dx.doi.org/10.3390/catal12080821.

Texte intégral
Résumé :
Developing a green, practical and efficient method for the formation of C–C and C–Heteroatom bonds is an important topic in modern organic synthetic chemistry. In recent years, the I2/DMSO catalytic system has attracted wide attention because of its green, high efficiency, atomic economy, low cost, mild reaction conditions and it is environment-friendly, which is more in line with the requirements of sustainable chemistry. Heteroatom-containing compounds have shown lots of important applications in pharmaceutical synthesis, agrochemicals, material chemistry and organic dyes. At present, the I2/DMSO catalytic system has been successfully applied to the synthesis of various heteroatom-containing compounds. The C–C and C–Heteroatom bonds have been formed efficiently, which has been proved to be a green and mild catalytic system. In this review, the research achievements of the I2/DMSO catalytic system in the formation of C–C and C–Heteroatom bonds from 2015 to date are described, and the research area is prospected. This review attempts to reveal the general law of iodine catalysis and lay a foundation for the design of new reactions.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Skalik, Joanna, Marek Koprowski, Ewa Różycka-Sokołowska et Piotr Bałczewski. « The hetero-Friedel-Crafts-Bradsher Cyclizations with Formation of Ring Carbon-Heteroatom (P, S) Bonds, Leading to Organic Functional Materials ». Materials 13, no 21 (23 octobre 2020) : 4751. http://dx.doi.org/10.3390/ma13214751.

Texte intégral
Résumé :
The interest in functional materials possessing improved properties led to development of new methods of their synthesis, which allowed to obtain new molecular arrangements with carbon and heteroatom motifs. Two of the classical reactions of versatile use are the Friedel-Crafts and the Bradsher reactions, which in the new heteroatomic versions allow to replace ring carbon atoms by heteroatoms. In the present work, we review methods of synthesis of C–S and C–P bonds utilizing thia- and phospha-Friedel-Crafts-Bradsher cyclizations. Single examples of C–As and lack of C–Se bond formation, involving two of the closest neighbors of P and S in the periodic table, have also been noted. Applications of the obtained π-conjugated molecules, mainly as semiconducting materials, flame retardants, and resins hardeners, designed on the basis of five- and six-membered cyclic molecules containing ring phosphorus and sulfur atoms, are also included. This comprehensive review covers literature up to August 2020.
Styles APA, Harvard, Vancouver, ISO, etc.
3

Kadjo, François Kassi, Sopi Thomas Affi, Yao Silvère Diki N’guessan, Mamadou Guy-Richard Koné, Georges Stéphane Dembélé et Nahossé Ziao. « Theoretical Characterization of the Hydrogen Bonding Interaction Sites of Mycolactone C Using the ONIOM Method ». Mediterranean Journal of Chemistry 11, no 2 (26 avril 2021) : 185. http://dx.doi.org/10.13171/mjc02104261574mgrk.

Texte intégral
Résumé :
<p>In this work, the ONIOM method, recognized for its effectiveness on large molecules, was used to determine the geometric, energetic, and spectroscopic parameters of hydrogen bond interactions of mycolactone C. Mycolactone C; one of the most virulent forms of toxin, found in Africa and Australia. It has eight (08) oxygen heteroatoms which are all hybridized sp<sup>2</sup> and sp<sup>3</sup>. Using quantum chemistry methods, at the ONIOM level (B3LYP/6-311+G (d, p): AM1), we have determined the preferential binding sites of the hydrogen bonds in the eight mycolactone C oxygen heteroatoms studied. Analysis of the results revealed that the heteroatom O<sub>5</sub>sp<sup>2</sup> is the most suitable site for creating a strong hydrogen bond based on the geometric, energetic (free enthalpy of complexation), and spectroscopic (vibration frequency shifts) parameters. Identifying this O5sp2 heteroatom is a significant step forward in developing a methodology for eradicating the infection and the destructive effects of this toxin.</p>
Styles APA, Harvard, Vancouver, ISO, etc.
4

Sharma, Mitu, Bhupendra Adhikari, Raymond Femi Awoyemi, Amanda M. Perkins, Alison K. Duckworth, Bruno Donnadieu, David O. Wipf, Sean L. Stokes et Joseph P. Emerson. « Copper(II) NHC Catalyst for the Formation of Phenol from Arylboronic Acid ». Chemistry 4, no 2 (7 juin 2022) : 560–75. http://dx.doi.org/10.3390/chemistry4020040.

Texte intégral
Résumé :
Arylboronic acids are commonly used in modern organic chemistry to form new C–C and C–heteroatom bonds. These activated organic synthons show reactivity with heteroatoms in a range of substrates under ambient oxidative conditions. This broad reactivity has limited their use in protic, renewable solvents like water, ethanol, and methanol. Here, we report our efforts to study and optimize the activation of arylboronic acids by a copper(II) N-heterocyclic carbene (NHC) complex in aqueous solution and in a range of alcohols to generate phenol and aryl ethers, respectively. The optimized reactivity showcases the ability to make targeted C–O bonds, but also identifies conditions where water and alcohol activation could be limiting for C–C and C–heteroatom bond-forming reactions. This copper(II) complex shows strong reactivity toward arylboronic acid activation in aqueous medium at ambient temperature. The relationship between product formation and temperature and catalyst loading are described. Additionally, the effects of buffer, pH, base, and co-solvent are explored with respect to phenol and ether generation reactions. Characterization of the new copper(II) NCN-pincer complex by X-ray crystallography, HR-MS, cyclic voltammetry, FT-IR and UV-Vis spectral studies is reported.
Styles APA, Harvard, Vancouver, ISO, etc.
5

Zhou, Fengtao, et Qian Cai. « Recent advances in copper-catalyzed asymmetric coupling reactions ». Beilstein Journal of Organic Chemistry 11 (15 décembre 2015) : 2600–2615. http://dx.doi.org/10.3762/bjoc.11.280.

Texte intégral
Résumé :
Copper-catalyzed (or -mediated) asymmetric coupling reactions have received significant attention over the past few years. Especially the coupling reactions of aryl or alkyl halides with nucleophiles became a very powerful tool for the formation of C–C, C–N, C–O and other carbon–heteroatom bonds as well as for the construction of heteroatom-containing ring systems. This review summarizes the recent progress in copper-catalyzed asymmetric coupling reactions for the formation of C–C and carbon–heteroatom bonds.
Styles APA, Harvard, Vancouver, ISO, etc.
6

Peng, Haihui, Rong Cai, Chang Xu, Hao Chen et Xiaodong Shi. « Nucleophile promoted gold redox catalysis with diazonium salts : C–Br, C–S and C–P bond formation through catalytic Sandmeyer coupling ». Chemical Science 7, no 9 (2016) : 6190–96. http://dx.doi.org/10.1039/c6sc01742h.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Kim, Jin Hee, Jong Hun Han, Jae-Hyung Wee, Go Bong Choi, Seungki Hong et Yoong Ahm Kim. « Importance of Doping Sequence in Multiple Heteroatom-Doped Reduced Graphene Oxide as Efficient Oxygen Reduction Reaction Electrocatalysts ». Applied Nano 2, no 3 (7 septembre 2021) : 267–77. http://dx.doi.org/10.3390/applnano2030019.

Texte intégral
Résumé :
Multiple heteroatom-doped graphene is of great interest for developing an efficient electrocatalyst for oxygen reduction reaction (ORR). To maximize the electrocatalytic performance of doped graphene, the competitive doping mechanism caused by the different atomic sizes of dopants should be developed. Herein, three different heteroatoms (e.g., N, P and B) are competitively introduced into reduced graphene oxide (RGO) using both single- and two-step processes. The total quantity of heteroatoms for ternary RGO synthesized using the two-step process is lower than that when using the single-step process. Higher ORR electrocatalytic activity for the two-step-synthesized RGO compared to the single-step-synthesized RGO can be explained by: (a) a high amount of P atoms; (b) the fact that B doping itself decreases the less electrocatalytic N moieties such as pyrrole and pyridine and increases the high electrocatalytic moieties such as quaternary N; (c) a high amount of B atoms itself within the RGO act as an electrocatalytic active center for O2 adsorption; and (d) a small amount of substitutional B might increase the electrical conductivity of RGO. Our findings provide new insights into the design of heteroatom-doped carbon materials with excellent electrocatalytic performance.
Styles APA, Harvard, Vancouver, ISO, etc.
8

Desnoyer, Addison N., et Jennifer A. Love. « Recent advances in well-defined, late transition metal complexes that make and/or break C–N, C–O and C–S bonds ». Chemical Society Reviews 46, no 1 (2017) : 197–238. http://dx.doi.org/10.1039/c6cs00150e.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Beletskaya, Irina P. « Palladium catalyzed C-C and C-heteroatom bond formation reactions ». Pure and Applied Chemistry 69, no 3 (1 janvier 1997) : 471–76. http://dx.doi.org/10.1351/pac199769030471.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
10

Cai, Xiao-Hua, Meng-Zhi Yang et Bing Xie. « Recent Investigations on the Functionalizations of C(sp3)-H Bonds Adjacent to a Heteroatom ». Letters in Organic Chemistry 16, no 10 (23 août 2019) : 779–801. http://dx.doi.org/10.2174/1570178616666190123131353.

Texte intégral
Résumé :
The selective functionalization of unactivated C(sp3)-H bonds has been regarded as an efficient and atom-economical approach for the formation of carbon-carbon or carbon-heteroatom bonds in modern organic synthesis. Especially, the oxidative activation of C(sp3)–H bonds adjacent to a heteroatom exhibits quite significant features in synthetic chemistry. For example, the direct functionalizations of amines, amides and ethers present important alternative tactics for the synthesis of various novel and useful molecules from simple starting materials. Many remarkable achievements in the area had continuously been made in the past decades. Here we reviewed recent investigations on the transformations of C(sp3)-H bond adjacent to a heteroatom.
Styles APA, Harvard, Vancouver, ISO, etc.
11

Zhou, Yu, Ping Wu, Fanshu Cao, Lei Shi, Ni Zhang, Zuqian Xue et Gen Luo. « Mechanistic insights into rare-earth-catalysed C–H alkylation of sulfides : sulfide facilitating alkene insertion and beyond ». RSC Advances 12, no 22 (2022) : 13593–99. http://dx.doi.org/10.1039/d2ra02180c.

Texte intégral
Résumé :
The alkene insertion via the heteroatom-containing substrate facilitated mechanism were computationally revealed in rare-earth-catalyzed C–H alkylation of sulfides and other heteroatom-containing substrates such as pyridines and anisoles.
Styles APA, Harvard, Vancouver, ISO, etc.
12

Arshadi, Sattar, Alireza Banaei, Aazam Monfared, Saeideh Ebrahimiasl et Akram Hosseinian. « Cross-dehydrogenative coupling reactions between arenes (C–H) and carboxylic acids (O–H) : a straightforward and environmentally benign access to O-aryl esters ». RSC Advances 9, no 30 (2019) : 17101–18. http://dx.doi.org/10.1039/c9ra01941c.

Texte intégral
Résumé :
Transition-metal catalyzed cross-dehydrogenative-coupling encompass atom economical methods for the construction of various carbon–carbon and carbon–heteroatom bonds by combining two C(X)–H (X = heteroatom) bonds.
Styles APA, Harvard, Vancouver, ISO, etc.
13

Daoust, Benoit, Nicolas Gilbert, Paméla Casault, François Ladouceur et Simon Ricard. « 1,2-Dihaloalkenes in Metal-Catalyzed Reactions ». Synthesis 50, no 16 (9 juillet 2018) : 3087–113. http://dx.doi.org/10.1055/s-0037-1610174.

Texte intégral
Résumé :
1,2-Dihaloalkenes readily undergo simultaneous or sequential difunctionalization through transition-metal-catalyzed reactions, which makes them attractive building blocks for complex unsaturated motifs. This review summarizes recent applications of such transformations in C–C and C–heteroatom bond forming processes. The facile synthesis of stereodefined alkene derivatives, as well as aromatic and heteroatomic­ compounds, from 1,2-dihaloalkenes is thus outlined.1 Introduction2 Synthesis of 1,2-Dihaloalkenes3 C–C Bond Forming Reactions4 C–Heteroatom Bond Forming Reactions5 Conclusion
Styles APA, Harvard, Vancouver, ISO, etc.
14

Bonne, Damien, Thierry Constantieux, Yoann Coquerel et Jean Rodriguez. « Asymmetric organocascades involving the formation of two C–heteroatom bonds from two distinct heteroatoms ». Organic & ; Biomolecular Chemistry 10, no 20 (2012) : 3969. http://dx.doi.org/10.1039/c2ob25248a.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
15

Paira, Moumita. « Recent Developments of Palladium-Catalyzed C(sp3)/C(sp2)-H Bond Functionalizations Assisted by 8-Aminoquinoline Bidentate Directing Group ». Asian Journal of Chemistry 34, no 8 (2022) : 1958–74. http://dx.doi.org/10.14233/ajchem.2022.23774.

Texte intégral
Résumé :
Recently growing demand for cleaner, direct even more regioselective reaction sequences, the formation of carbon-carbon or carbon-heteroatom bonds through C-H activation has developed as a unique methodology. Since the pioneering work of Daugulis on the use of the 8-aminoquinoline auxiliaries as removable bidentate directing groups in palladium-catalyzed C-H bond activations has emerged as a ground breaking strategy for the construction of carbon-carbon or carbon-heteroatom bonds. Hence, this review intends to cover most of the recent advances on 8-aminoquinoline directed palladium-catalyzed C(sp3)/C(sp2)–H bonds functionalizations and highlighted the synthesis of C-branched glycosides.
Styles APA, Harvard, Vancouver, ISO, etc.
16

Pan, Meilan, Junjian Li et Bingjun Pan. « Identifying the Active Sites of Heteroatom Graphene as a Conductive Membrane for the Electrochemical Filtration of Organic Contaminants ». International Journal of Molecular Sciences 23, no 23 (29 novembre 2022) : 14967. http://dx.doi.org/10.3390/ijms232314967.

Texte intégral
Résumé :
The dopants of sulfur, nitrogen, or both, serving as the active sites, into the graphitic framework of graphene is an efficient strategy to improve the electrochemical performance of electrochemical membrane filtration. However, the covalent bonds between the doped atoms and the substrate that form different functional groups have a significant role in the specific activity for pollutant degradation. Herein, we found that the singly doped heteroatom graphene (NG and SG) achieved superior removal efficiency of pollutants as compared with that of the double doped heteroatom graphene (SNG). Mechanism studies showed that the doped N of NG presented as graphitic N and substantially increased electron transfer, whereas the doped S of SG posed as -C-SOx-C- provided more adsorption sites to improve electrochemical performance. However, in the case of SNG, the co-doped S and N cannot form the efficient graphitic N and -C-SOx-C- for electrochemical degradation, resulting in a low degradation efficiency. Through the fundamental insights into the bonding of the doped heteroatom on graphene, this work furnishes further directives for the design of desirable heteroatom graphene for membrane filtration.
Styles APA, Harvard, Vancouver, ISO, etc.
17

Kumar, Gautam, Sourav Roy et Indranil Chatterjee. « Tris(pentafluorophenyl)borane catalyzed C–C and C–heteroatom bond formation ». Organic & ; Biomolecular Chemistry 19, no 6 (2021) : 1230–67. http://dx.doi.org/10.1039/d0ob02478c.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
18

Dhakshinamoorthy, Amarajothi, Abdullah M. Asiri et Hermenegildo Garcia. « Metal–organic frameworks catalyzed C–C and C–heteroatom coupling reactions ». Chemical Society Reviews 44, no 7 (2015) : 1922–47. http://dx.doi.org/10.1039/c4cs00254g.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
19

Bedford, Robin B. « Palladacyclic catalysts in C–C and C–heteroatom bond-forming reactions ». Chem. Commun., no 15 (2003) : 1787–96. http://dx.doi.org/10.1039/b211298c.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
20

Baranano, David, Grace Mann et John F. Hartwig. « Nickel and Palladium-Catalyzed Cross-Couplings that Form Carbon-Heteroatom and Carbon-Element Bonds ». Current Organic Chemistry 1, no 3 (septembre 1997) : 287–305. http://dx.doi.org/10.2174/1385272801666220124194647.

Texte intégral
Résumé :
The transition-metal catalyzed addition of heteroatom nucleophiles to aryl and vinyl halides is reviewed. This chemistry typically involves a nickel- or palladium-based catalyst containing phosphine ligands. In recently developed palladium-catalyzed chemistry, aryl halides react with amines in the presence of base to form arylamines. In similar chemistry cataly­zed by both nickel and palladium, aryl and vinyl halides react with alkali metal or tin thiolates or selenides to form aryl and vinyl sulfides, while the reaction of different phosphorus compounds, such as phosphides, phosphonates, and phosphonites, with aryl halides gives compounds with new aryl-p· linkages. In addition to these typically nucleophilic heteroatoms, electrophilic heteroatoms such as boron, silicon, tin, and germanium have also been coupled to aryl electrophiles. The review closes with a brief summary of the general reaction pathways of these C-X bond-forming processes.
Styles APA, Harvard, Vancouver, ISO, etc.
21

Shi, Xiaoyan, Lujun Fang, Handong Peng, Xizhan Deng et Zhipeng Sun. « Metal-Organic Framework-Derived NiSe Embedded into a Porous Multi-Heteroatom Self-Doped Carbon Matrix as a Promising Anode for Sodium-Ion Battery ». Nanomaterials 12, no 19 (26 septembre 2022) : 3345. http://dx.doi.org/10.3390/nano12193345.

Texte intégral
Résumé :
A self-doping strategy is applied to prepare a multi-heteroatom-doped carbonaceous nickel selenide NiSe@C composite by introducing N and P-containing ligand hexa(4-carboxyl-phenoxy)-cyclotriphosphazene (HCTP-COOH) into a Ni-based MOF precursor. The MOF-derived NiSe@C composite is characterized as NiSe particles nested in a multi-heteroatom-doped carbon matrix. The multi-heteroatom-doped NiSe@C composite with a unique structure shows an excellent sodium-ion storage property. The Na-ion battery from the NiSe@C electrode exhibits a capacity of 447.8 mA h g−1 at 0.1 A g−1, a good rate capability (240.3 mA h g−1 at 5.0 A g−1), and excellent cycling life (227.8 mAh g−1 at 5.0 A g−1 for 1200). The prospects of the synthesis methodology and application of NiSe@C in sodium-ion batteries (SIBs) devices are presented.
Styles APA, Harvard, Vancouver, ISO, etc.
22

Zheng, Xingqun, Ling Zhang, Wei He, Li Li et Shun Lu. « Heteroatom-Doped Nickel Sulfide for Efficient Electrochemical Oxygen Evolution Reaction ». Energies 16, no 2 (12 janvier 2023) : 881. http://dx.doi.org/10.3390/en16020881.

Texte intégral
Résumé :
Heteroatom doping is an effective strategy to regulate electrocatalysts for the oxygen evolution reaction (OER). Nonmetal heteroatoms can effectively engineer geometric and electronic structures and activating surface sites of catalysts due to their unique radius and the electronegativity of nonmetal atoms. Hence, the surface geometric and electronic structure and activity of nonmetal atoms (X, X = B, C, N, O, P)-doped Ni3S2 (X-Ni3S2) were studied to screen high-performance Ni3S2-based OER electrocatalysts through density functional theory calculation. Theoretical results demonstrated that dopants in X-Ni3S2 can alter bond length and charge of surface, modify active sites for intermediates adsorption, and adjust the theoretical overpotential. Among all dopants, C can effectively modulate surface structure, activate surface sites, weaken the adsorption of key intermediates, decrease theoretical overpotential, and enable C-Ni3S2 with the best theoretical OER activity among all X-Ni3S2 with the lowest theoretical overpotential (0.46 eV). Further experimental results verified that the synthesized C-Ni3S2 performed an improved OER activity in the alkaline condition with a considerably enhanced overpotential of 261 mV at 10 mA cm−2 as well as a Tafel slope of 95 mV dec−1 compared to pristine Ni3S2.
Styles APA, Harvard, Vancouver, ISO, etc.
23

Haider, Muhammad, Daniele Castello, Karol Michalski, Thomas Pedersen et Lasse Rosendahl. « Catalytic Hydrotreatment of Microalgae Biocrude from Continuous Hydrothermal Liquefaction : Heteroatom Removal and Their Distribution in Distillation Cuts ». Energies 11, no 12 (1 décembre 2018) : 3360. http://dx.doi.org/10.3390/en11123360.

Texte intégral
Résumé :
To obtain drop-in fuel properties from 3rd generation biomass, we herein report the catalytic hydrotreatment of microalgae biocrude, produced from hydrothermal liquefaction (HTL) of Spirulina. Our contribution focuses on the effect of temperature, initial H2 pressure, and residence time on the removal of heteroatoms (O and N) in a batch hydrotreating setup. In contrast to common experimental protocols for hydrotreating at batch scale, we devised a set of two-level factorial experiments and studied the most influential parameters affecting the removal of heteroatoms. It was found that up to 350 °C, the degree of deoxygenation (de-O) is mainly driven by temperature, whereas the degree of denitrogenation (de-N) also relies on initial H2 pressure and temperature-pressure interaction. Based on this, complete deoxygenation was obtained at mild operating conditions (350 °C), reaching a concurrent 47% denitrogenation. Moreover, three optimized experiments are reported with 100% removal of oxygen. In addition, the analysis by GC-MS and Sim-Dis gives insight to the fuel quality. The distribution of heteroatom N in lower (<340 °C) and higher (>340 °C) fractional cuts is studied by a fractional distillation unit following ASTM D-1160. Final results show that 63–68% of nitrogen is concentrated in higher fractional cuts.
Styles APA, Harvard, Vancouver, ISO, etc.
24

Saget, Tanguy, et Nicolai Cramer. « Heteroatom Nucleophile Induced C–C Fragmentations to Access Functionalized Allenes ». CHIMIA International Journal for Chemistry 66, no 4 (25 avril 2012) : 205–7. http://dx.doi.org/10.2533/chimia.2012.205.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
25

Kang, Eunsu, Hyun Tae Kim et Jung Min Joo. « Transition-metal-catalyzed C–H functionalization of pyrazoles ». Organic & ; Biomolecular Chemistry 18, no 32 (2020) : 6192–210. http://dx.doi.org/10.1039/d0ob01265c.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
26

Xie, Peipei, Wei Guo, Dimei Chen et Yuanzhi Xia. « Multiple pathways for C–H cleavage in cationic Cp*Rh(iii)-catalyzed C–H activation without carboxylate assistance : a computational study ». Catalysis Science & ; Technology 8, no 16 (2018) : 4005–9. http://dx.doi.org/10.1039/c8cy00870a.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
27

Wang, Zhong-Xia, et Bo Yang. « Chemical transformations of quaternary ammonium salts via C–N bond cleavage ». Organic & ; Biomolecular Chemistry 18, no 6 (2020) : 1057–72. http://dx.doi.org/10.1039/c9ob02667c.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
28

BELETSKAYA, I. P. « ChemInform Abstract : Palladium Catalyzed C-C and C-Heteroatom Bond Formation Reactions ». ChemInform 28, no 28 (3 août 2010) : no. http://dx.doi.org/10.1002/chin.199728255.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
29

Zeng, Xiaoming, et Xuefeng Cong. « Chromium-Catalyzed Cross-Coupling Reactions by Selective Activation of Chemically Inert Aromatic C–O, C–N, and C–H Bonds ». Synlett 32, no 13 (11 mai 2021) : 1343–53. http://dx.doi.org/10.1055/a-1507-4153.

Texte intégral
Résumé :
AbstractTransition-metal-catalyzed cross-coupling has emerged as one of the most powerful and useful tools for the formation of C–C and C–heteroatom bonds. Given the shortage of resources of precious metals on Earth, the use of Earth-abundant metals as catalysts in developing cost-effective strategies for cross-coupling is a current trend in synthetic chemistry. Compared with the achievements made using first-row nickel, iron, cobalt, and even manganese catalysts, the group 6 metal chromium has rarely been used to promote cross-coupling. This perspective covers recent advances in chromium-catalyzed cross-coupling reactions in transformations of chemically inert C(aryl)–O, C(aryl)–N, and C(aryl)–H bonds, offering selective strategies for molecule construction. The ability of low-valent Cr with a high-spin state to participate in two-electron oxidative addition is highlighted; this is different from the mechanism involving single-electron transfer that is usually assigned to chromium-mediated transformations.1 Introduction2 Chromium-Catalyzed Kumada Coupling of Nonactivated C(aryl)–O and C(aryl)–N Bonds3 Chromium-Catalyzed Reductive Cross-Coupling of Two Nonactivated C(aryl)–Heteroatom Bonds4 Chromium-Catalyzed Functionalization of Nonactivated C(aryl)–H Bonds5 Conclusions and Outlook
Styles APA, Harvard, Vancouver, ISO, etc.
30

Geurts, Koen, Stephen P. Fletcher, Anthoni W. van Zijl, Adriaan J. Minnaard et Ben L. Feringa. « Copper-catalyzed asymmetric allylic substitution reactions with organozinc and Grignard reagents ». Pure and Applied Chemistry 80, no 5 (1 janvier 2008) : 1025–37. http://dx.doi.org/10.1351/pac200880051025.

Texte intégral
Résumé :
Asymmetric allylic alkylations (AAAs) are among the most powerful C-C bond-forming reactions. We present a brief overview of copper-catalyzed AAAs with organometallic reagents and discuss our own contributions to this field. Work with zinc reagents and phosphoramidite ligands provided a framework for later developments which employ Grignard reagents and ferrocenyl ligands. High yields and excellent regioselectivities and enantioselectivities are achieved. The AAAs may be more general than previously envisioned, in terms of using substrates functionalized with heteroatoms at various positions; heteroatom substituents at the γ-position provide densely functionalized building blocks. These h-AAA reactions rely on the design of appropriate substrates containing heteroatoms and have allowed us to demonstrate viable new approaches toward the synthesis of versatile organic building blocks. We illustrate that the chiral secondary allylic alcohols, primary homo-allylic alcohols and amines can readily be obtained in high enantiomeric purity in a catalytic asymmetric fashion by copper-catalyzed AAAs. Furthermore, we show that manipulation of the terminal olefin provides chiral building blocks where the ee of the starting materials is preserved.
Styles APA, Harvard, Vancouver, ISO, etc.
31

Merino, Estíbaliz, et Cristina Nevado. « Addition of CF3 across unsaturated moieties : a powerful functionalization tool ». Chem. Soc. Rev. 43, no 18 (2014) : 6598–608. http://dx.doi.org/10.1039/c4cs00025k.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
32

Kamanna, Kantharaju, et Santosh Y. Khatavi. « Microwave-accelerated Carbon-carbon and Carbon-heteroatom Bond Formation via Multi-component Reactions : A Brief Overview ». Current Microwave Chemistry 7, no 1 (23 juin 2020) : 23–39. http://dx.doi.org/10.2174/2213346107666200218124147.

Texte intégral
Résumé :
Multi-Component Reactions (MCRs) have emerged as an excellent tool in organic chemistry for the synthesis of various bioactive molecules. Among these, one-pot MCRs are included, in which organic reactants react with domino in a single-step process. This has become an alternative platform for the organic chemists, because of their simple operation, less purification methods, no side product and faster reaction time. One of the important applications of the MCRs can be drawn in carbon- carbon (C-C) and carbon-heteroatom (C-X; X = N, O, S) bond formation, which is extensively used by the organic chemists to generate bioactive or useful material synthesis. Some of the key carbon- carbon bond forming reactions are Grignard, Wittig, Enolate alkylation, Aldol, Claisen condensation, Michael and more organic reactions. Alternatively, carbon-heteroatoms containing C-N, C-O, and C-S bond are also found more important and present in various heterocyclic compounds, which are of biological, pharmaceutical, and material interest. Thus, there is a clear scope for the discovery and development of cleaner reaction, faster reaction rate, atom economy and efficient one-pot synthesis for sustainable production of diverse and structurally complex organic molecules. Reactions that required hours to run completely in a conventional method can now be carried out within minutes. Thus, the application of microwave (MW) radiation in organic synthesis has become more promising considerable amount in resource-friendly and eco-friendly processes. The technique of microwaveassisted organic synthesis (MAOS) has successfully been employed in various material syntheses, such as transition metal-catalyzed cross-coupling, dipolar cycloaddition reaction, biomolecule synthesis, polymer formation, and the nanoparticle synthesis. The application of the microwave-technique in carbon-carbon and carbon-heteroatom bond formations via MCRs with major reported literature examples are discussed in this review.
Styles APA, Harvard, Vancouver, ISO, etc.
33

Blank, Lena, Maurizio Fagnoni, Stefano Protti et Magnus Rueping. « Visible Light-Promoted Formation of C–B and C–S Bonds under Metal- and Photocatalyst-Free Conditions ». Synthesis 51, no 05 (6 février 2019) : 1243–52. http://dx.doi.org/10.1055/s-0037-1611648.

Texte intégral
Résumé :
A green, efficient, photoinduced synthesis of arylboronic esters and aryl sulfides has been developed. Bench stable arylazo sulfones were used as radical precursors for a photocatalyst- and additive-free carbon–heteroatom bond formation under visible light. The protocols are applicable to a wide range of substrates, providing products in good yields.
Styles APA, Harvard, Vancouver, ISO, etc.
34

Shainyan, Bagrat A. « Conjugative Stabilization versus Anchimeric Assistance in Carbocations ». Molecules 28, no 1 (21 décembre 2022) : 38. http://dx.doi.org/10.3390/molecules28010038.

Texte intégral
Résumé :
In this study, an old concept of anchimeric assistance is viewed from a different angle. Primary cations with two different heteroatomic substituents in the α-position to the cationic carbon atom CHXY–CH2+ (X, Y = Me2N, MeO, Me3Si, Me2P, MeS, MeS, Br) can be stabilized by the migration of either the X or Y group to the cation center. In each case, the migration can be either complete, resulting in the transfer of the migrating group to the adjacent carbon atom and the formation of a secondary carbocation stabilized by the remaining heteroatom, or incomplete, leading to an anchimerically assisted iranium ion. For all combinations of the above groups, these transformations have been studied by theoretical analysis at the MP2/aug-cc-pVTZ level and were shown to occur depending on the ability of anchimeric assistance by X and Y, as well as the conformation of the starting primary carbocation. In the conformers of α-amino cations with the p-orbital, C–N bond and the nitrogen lone pair in one plane, the Me2N group migrates to the cationic center to give aziranium ions. Otherwise, the second heteroatom is shifted to give iminium ions, without or with very slight anchimeric assistance. In the α-methoxy cations, the MeO group can be shifted to the cationic center to give the O-anchimerically assisted ions as local minima, the global minima being the ions anchimerically assisted by another heteroatom. The electropositive silicon tends to migrate towards the cationic center, but with the formation of a π-complex of the Me3Si cation with the C=C bond rather than a Si-anchimerically assisted cation. The phosphorus atom can either fully migrate to the cationic center (X = P, Y = S, Se) or form anchimerically stabilized phosphiranium ions (X = P, Y = O, Si, Br). The order of the anchimeric assistance for the heaviest atoms decreases in the order Se >> S > Br.
Styles APA, Harvard, Vancouver, ISO, etc.
35

Drusan, Michal, et Radovan Šebesta. « Enantioselective C–C and C–heteroatom bond forming reactions using chiral ferrocene catalysts ». Tetrahedron 70, no 4 (janvier 2014) : 759–86. http://dx.doi.org/10.1016/j.tet.2013.11.012.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
36

Colby, Denise A., Robert G. Bergman et Jonathan A. Ellman. « Rhodium-Catalyzed C−C Bond Formation via Heteroatom-Directed C−H Bond Activation ». Chemical Reviews 110, no 2 (10 février 2010) : 624–55. http://dx.doi.org/10.1021/cr900005n.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
37

Dhakshinamoorthy, Amarajothi, Abdullah M. Asiri et Hermenegildo Garcia. « ChemInform Abstract : Metal-Organic Frameworks Catalyzed C-C and C-Heteroatom Coupling Reactions ». ChemInform 46, no 22 (15 mai 2015) : no. http://dx.doi.org/10.1002/chin.201522271.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
38

Ribas, Xavi, et Imma Güell. « Cu(I)/Cu(III) catalytic cycle involved in Ullmann-type cross-coupling reactions ». Pure and Applied Chemistry 86, no 3 (20 mars 2014) : 345–60. http://dx.doi.org/10.1515/pac-2013-1104.

Texte intégral
Résumé :
Abstract Copper-catalyzed cross-coupling reactions for C–heteroatom bond formation have attracted numerous research groups in the past 15 years aiming at finding more efficient methodologies under milder conditions. The use of auxiliary ligands has tremendously improved Ullmann-type couplings although a general methodology for different heteroatom-nucleophiles is still lacking. Mechanistic insights are seen as a clue for designing new effective, broad-scope and general methodologies. In this review we describe the widely discussed mechanistic options for this reaction and the use of model compounds to unravel key mechanistic aspects for copper-catalyzed C–heteroatom transformations. Stable aryl-Cu(III) species in model systems are shown to be reliable active catalysts in the coupling of a broad nucleophile scope such as phenols, amides, sulfides, selenides, phosphites, halides and also activated methylene susbtrates for carbon–carbon couplings.
Styles APA, Harvard, Vancouver, ISO, etc.
39

Ara Begum, Shameem, Jun Terao et Nobuaki Kambe. « Conversion of (sp3)C–F Bonds of Alkyl Fluorides to (sp3)C–Heteroatom (Heteroatom = I, SR, SeR, TeR) Bonds by the Use of Magnesium Reagents Having Heteroatom Substituents ». Chemistry Letters 36, no 1 (janvier 2007) : 196–97. http://dx.doi.org/10.1246/cl.2007.196.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
40

Bonne, Damien, Thierry Constantieux, Yoann Coquerel et Jean Rodriguez. « ChemInform Abstract : Asymmetric Organocascades Involving the Formation of Two C-Heteroatom Bonds from Two Distinct Heteroatoms ». ChemInform 43, no 40 (7 septembre 2012) : no. http://dx.doi.org/10.1002/chin.201240232.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
41

Haldar, Chabush, Md Emdadul Hoque, Jagriti Chaturvedi, Mirja Md Mahamudul Hassan et Buddhadeb Chattopadhyay. « Ir-catalyzed proximal and distal C–H borylation of arenes ». Chemical Communications 57, no 97 (2021) : 13059–74. http://dx.doi.org/10.1039/d1cc05104k.

Texte intégral
Résumé :
Over the past two decades, the C–H bond activation and functionalization reaction has been known as a prevailing method for the construction of carbon–carbon and carbon–heteroatom bonds using various transition metal catalysts.
Styles APA, Harvard, Vancouver, ISO, etc.
42

Zhang, Ruiquan, Qiongyu Liu, Ming Wan, Zhenhua Yao et Maocong Hu. « Heteroatom-Doped Carbon-Based Catalysts Synthesized through a “Cook-Off” Process for Oxygen Reduction Reaction ». Processes 12, no 2 (25 janvier 2024) : 264. http://dx.doi.org/10.3390/pr12020264.

Texte intégral
Résumé :
The development of efficient and low-cost non-metallic catalysts is of great significance for the oxygen reduction reaction (ORR) in fuel cells. Heteroatom-doped carbon-based catalysts are one of the popular candidates, although their preparation method is still under exploration. In this work, single (CS)-, double (NCS)-, and triple (NBCS)-heteroatom-doped carbon-based catalysts were successfully prepared by a “cook-off” process. The morphology, elemental composition, and bonding structure of the catalysts were investigated by SEM, TEM, Raman spectra, BET, and XPS. ORR catalytic performance measurements suggested an activity trend of CS < NCS < NBCS, and NBCS demonstrated better methanol resistance and slightly higher stability than the commercial Pt/C catalyst, as evaluated with both rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) systems. The mechanism for the promoted performance was also proposed based on the conductivity of the catalysts. In this paper, the heteroatoms N, B, and S were co-doped into activated carbon using a simple, fast, and efficient preparation method with high electrical conductivity and also increased active sites, showing high electrocatalytic activity and good stability. This work provides a new approach to preparing highly active non-Pt catalysts for oxygen reduction reactions.
Styles APA, Harvard, Vancouver, ISO, etc.
43

Hu, Jiefeng, Matthias Ferger, Zhuangzhi Shi et Todd B. Marder. « Recent advances in asymmetric borylation by transition metal catalysis ». Chemical Society Reviews 50, no 23 (2021) : 13129–88. http://dx.doi.org/10.1039/d0cs00843e.

Texte intégral
Résumé :
We provide a comprehensive overview of transition metal-catalysed asymmetric borylation processes to construct C–B, C–C, and other C–heteroatom bonds with considerable attention devoted to the reaction modes and the mechanisms involved.
Styles APA, Harvard, Vancouver, ISO, etc.
44

Zhao, Feng, Bin Tan, Qing Li, Qi Tan et Huawen Huang. « Progress in C-C and C-Heteroatom Bonds Construction Using Alcohols as Acyl Precursors ». Molecules 27, no 24 (16 décembre 2022) : 8977. http://dx.doi.org/10.3390/molecules27248977.

Texte intégral
Résumé :
Acyl moiety is a common structural unit in organic molecules, thus acylation methods have been widely explored to construct various functional compounds. While the traditional Friedel–Crafts acylation processes work to allow viable construction of arylketones under harsh acid conditions, recent progress on developing acylation methods focused on the new reactivity discovery by exploiting versatile and easily accessible acylating reagents. Of them, alcohols are cheap, have low toxicity, and are naturally abundant feedstocks; thus, they were recently used as ideal acyl precursors in molecule synthesis for ketones, esters, amides, etc. In this review, we display and discuss recent advances in employing alcohols as unusual acyl sources to form C-C and C-heteroatom bonds, with emphasis on the substrate scope, limitations, and mechanism.
Styles APA, Harvard, Vancouver, ISO, etc.
45

Gong, Dawei, Bowen Hu, Jing Shi et Dafa Chen. « Intramolecular cyclization of a diruthenium complex : insight into the mechanism of heteroatom-directed intramolecular C–H/olefin coupling reactions ». Dalton Transactions 44, no 28 (2015) : 12507–10. http://dx.doi.org/10.1039/c5dt02071a.

Texte intégral
Résumé :
The reactivities of a trinuclear ruthenium complex with 1,5-hexadiene suggest that the CC double bond is the second directing group in transition-metal catalyzed heteroatom-directed intramolecular C–H/olefin coupling reactions.
Styles APA, Harvard, Vancouver, ISO, etc.
46

Deb, Mayukh, Jatinder Singh, Shuvadip Mallik, Susanta Hazra et Anil J. Elias. « Borylation, silylation and selenation of C–H bonds in metal sandwich compounds by applying a directing group strategy ». New Journal of Chemistry 41, no 23 (2017) : 14528–38. http://dx.doi.org/10.1039/c7nj02388j.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
47

Wu, Xiaohui, Longbin Cui, Pei Tang, Ziqi Hu, Ding Ma et Zujin Shi. « Synthesis and catalytic activity of heteroatom doped metal-free single-wall carbon nanohorns ». Chemical Communications 52, no 31 (2016) : 5391–93. http://dx.doi.org/10.1039/c5cc10683d.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
48

Dong, Jianyang, Xiaochen Wang, Zhen Wang, Hongjian Song, Yuxiu Liu et Qingmin Wang. « Metal-, photocatalyst-, and light-free late-stage C–H alkylation of N-heteroarenes with organotrimethylsilanes using persulfate as a stoichiometric oxidant ». Organic Chemistry Frontiers 6, no 16 (2019) : 2902–6. http://dx.doi.org/10.1039/c9qo00690g.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
49

Zhang, Jian, Jia Wang, Zexing Wu, Shuai Wang, Yumin Wu et Xien Liu. « Heteroatom (Nitrogen/Sulfur)-Doped Graphene as an Efficient Electrocatalyst for Oxygen Reduction and Evolution Reactions ». Catalysts 8, no 10 (19 octobre 2018) : 475. http://dx.doi.org/10.3390/catal8100475.

Texte intégral
Résumé :
Carbon nanomaterials are potential materials with their intrinsic structure and property in energy conversion and storage. As the electrocatalysts, graphene is more remarkable in electrochemical reactions. Additionally, heteroatoms doping with metal-free materials can obtain unique structure and demonstrate excellent electrocatalytic performance. In this work, we proposed a facile method to prepare bifunctional electrocatalyst which was constructed by nitrogen, sulfur doped graphene (NSG), which demonstrate superior properties with high activity and excellent durability compared with Pt/C and IrO2 for oxygen reduction (OR) and oxygen evolution (OE) reactions. Accordingly, these phenomena are closely related to the synergistic effect of doping with nitrogen and sulfur by rationally regulating the polarity of carbon in graphene. The current work expands the method towards carbon materials with heteroatom dopants for commercialization in energy-related reactions.
Styles APA, Harvard, Vancouver, ISO, etc.
50

Vargas, Carolina, Alina Mariana Balu, Juan Manuel Campelo, Camino Gonzalez-Arellano, Rafael Luque et Antonio Angel Romero. « Towards Greener and More Efficient C-C and C-Heteroatom Couplings : Present and Future ». Current Organic Synthesis 7, no 6 (1 décembre 2010) : 568–86. http://dx.doi.org/10.2174/157017910794328547.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
Vous pouvez également être intéressé par les bibliographies sur le sujet « C heteroatom » pour d’autres types de sources :
Thèses
Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!

Vers la bibliographie