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1.
Psychol Assess ; 35(11): 949-958, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37902664

RESUMO

We explored the networks and discriminant abilities of the current Psychosomatic Symptoms Scale (PSSS) in pharmacists for future abbreviation. Ten thousand seven hundred twenty-one pharmacists participated in this study through an online investigation. We used network analysis to reveal the central and bridge symptoms between the subscales (psychological and somatic symptoms) of the PSSS. Then, we utilized item response theory (IRT) to identify discriminant abilities of the current 26-item of PSSS. Over twenty percent of the pharmacists were troubled with significant psychosomatic issues during the pandemic. Risk factors included age, lack of support, and impaired general health conditions. The network analysis revealed that "Irritability" was central to the psychological subscale and "Fatigue" was central to the somatic subscale. "Irritability-Fatigue," "Fatigue-Obsession," and "Self-injury idea-Perineum discomfort" was bridging between the somatic and psychological subscales. IRT found that "Anhedonia," "Depression," "Tightness," "Palpitations," and "Difficulty breathing" were highly discriminated. A future version of PSSS could be abbreviated according to the highlighted items, and they should also be emphasized in future psychosomatic research and targets for intervention. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Pandemias , Farmacêuticos , Humanos , Anedonia , Bases de Dados Factuais , Fadiga/diagnóstico , Fadiga/epidemiologia
2.
J Am Chem Soc ; 145(20): 11415-11419, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37172099

RESUMO

Atomically dispersed catalysts such as single-atom catalysts have been shown to be effective in selectively oxidizing methane, promising a direct synthetic route to value-added oxygenates such as acetic acid or methanol. However, an important challenge of this approach has been that the loading of active sites by single-atom catalysts is low, leading to a low overall yield of the products. Here, we report an approach that can address this issue. It utilizes a metal-organic framework built with porphyrin as the linker, which provides high concentrations of binding sites to support atomically dispersed rhodium. It is shown that up to 5 wt% rhodium loading can be achieved with excellent dispersity. When used for acetic acid synthesis by methane oxidation, a new benchmark performance of 23.62 mmol·gcat-1·h-1 was measured. Furthermore, the catalyst exhibits a unique sensitivity to light, producing acetic acid (under illumination, up to 66.4% selectivity) or methanol (in the dark, up to 65.0% selectivity) under otherwise identical reaction conditions.

3.
Angew Chem Int Ed Engl ; 62(27): e202305568, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37141443

RESUMO

Direct synthesis of CH3 COOH from CH4 and CO2 is an appealing approach for the utilization of two potent greenhouse gases that are notoriously difficult to activate. In this Communication, we report an integrated route to enable this reaction. Recognizing the thermodynamic stability of CO2 , our strategy sought to first activate CO2 to produce CO (through electrochemical CO2 reduction) and O2 (through water oxidation), followed by oxidative CH4 carbonylation catalyzed by Rh single atom catalysts supported on zeolite. The net result was CH4 carboxylation with 100 % atom economy. CH3 COOH was obtained at a high selectivity (>80 %) and good yield (ca. 3.2 mmol g-1 cat in 3 h). Isotope labelling experiments confirmed that CH3 COOH is produced through the coupling of CH4 and CO2 . This work represents the first successful integration of CO/O2 production with oxidative carbonylation reaction. The result is expected to inspire more carboxylation reactions utilizing preactivated CO2 that take advantage of both products from the reduction and oxidation processes, thus achieving high atom efficiency in the synthesis.

4.
J Am Chem Soc ; 145(2): 769-773, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36594824

RESUMO

Oxidative methane (CH4) carbonylation promises a direct route to the synthesis of value-added oxygenates such as acetic acid (CH3COOH). Here, we report a strategy to realize oxidative CH4 carbonylation through immobilized Ir complexes on an oxide support. Our immobilization approach not only enables direct CH4 activation but also allows for easy separation and reutilization of the catalyst. Furthermore, we show that a key step, methyl migration, that forms a C-C bond, is sensitive to the electrophilicity of carbonyl, which can be tuned by a gentle reduction to the Ir centers. While the as-prepared catalyst that mainly featured Ir(IV) preferred CH3COOH production, a reduced catalyst featuring predominantly Ir(III) led to a significant increase of CH3OH production at the expense of the reduced yield of CH3COOH.


Assuntos
Irídio , Metano , Irídio/química , Metano/química , Oxirredução , Catálise , Óxidos
5.
ACS Nano ; 16(9): 15053-15062, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36048768

RESUMO

Advances in the synthesis and self-assembly of nanocrystals have enabled researchers to create a plethora of different nanoparticle superlattices. But while many superlattices with complex types of translational order have been realized, rotational order of nanoparticle building blocks within the lattice is more difficult to achieve. Self-assembled superstructures with atomically coherent nanocrystal lattices, which are desirable due to their exceptional electronic and optical properties, have been fabricated only for a few selected systems. Here, we combine experiments with molecular dynamics (MD) simulations to study the self-assembly of heterostructural nanocrystals (HNCs), consisting of a near-spherical quantum dot (QD) host decorated with a small number of epitaxially grown gold nanocrystal (Au NC) "patches". Self-assembly of these HNCs results in face-centered-cubic (fcc) superlattices with well-defined orientational relationships between the atomic lattices of both QD hosts and Au patches. MD simulations indicate that the observed dual atomic coherence is linked to the number, size, and relative positions of gold patches. This study provides a strategy for the design and fabrication of NC superlattices with large structural complexity and delicate orientational order.

6.
Burns Trauma ; 10: tkac019, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35910193

RESUMO

Background: Most traditional wound dressings only partially meet the needs of wound healing because of their single function. Patients usually suffer from the increasing cost of treatment and pain resulting from the frequent changing of wound dressings. Herein, we have developed a mutifunctional cryogel to promote bacterial infected wound healing based on a biocompatible polysaccharide. Methods: The multifunctional cryogel is made up of a compositive scaffold of chitosan (CS), gelatin (Gel) and tannic acid (TA) and in situ formed silver nanoparticles (Ag NPs). A liver bleeding rat model was used to evaluate the dynamic hemostasis performance of the various cryogels. In order to evaluate the antibacterial properties of the prepared cryogels, gram-positive bacterium Staphylococcus aureus (S. aureus) and gram-negative bacterium Escherichia coli (E. coli) were cultured with the cryogels for 12 h. Meanwhile, S. aureus was introduced to cause bacterial infection in vivo. After treatment for 2 days, the exudates from wound sites were dipped for bacterial colony culture. Subsequently, the anti-inflammatory effect of the various cryogels was evaluated by western blotting and enzyme-linked immunosorbent assay. Finally, full-thickness skin defect models on the back of SD rats were established to assess the wound healing performances of the cryogels. Results: Due to its porous structure, the multifunctional cryogel showed fast liver hemostasis. The introduced Ag NPs endowed the cryogel with an antibacterial efficiency of >99.9% against both S. aureus and E. coli. Benefited from the polyphenol groups of TA, the cryogel could inhibit nuclear factor-κB nuclear translocation and down-regulate inflammatory cytokines for an anti-inflammatory effect. Meanwhile, excessive reactive oxygen species could also be scavenged effectively. Despite the presence of Ag NPs, the cryogel did not show cytotoxicity and hemolysis. Moreover, in vivo experiments demonstrated that the biocompatible cryogel displayed effective bacterial disinfection and accelerated wound healing. Conclusions: The multifunctional cryogel, with fast hemostasis, antibacterial and anti-inflammation properties and the ability to promote cell proliferation could be widely applied as a wound dressing for bacterial infected wound healing.

7.
ACS Appl Mater Interfaces ; 14(36): 41013-41021, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36044296

RESUMO

Luminescent solar concentrators (LSCs) are a class of wave-guiding devices that can harvest solar light and concentrate it to targeted smaller areas. When coupled with photovoltaic devices (PVs), LSCs hold the potential to be integrated into various application setups, especially for building facade integration toward net-zero-energy buildings. Developing reliable LSC fabrication methods with easy scalability, high adaptability, and device controllability has been an important research topic. In this work, we report an ultrasonic nebulization-assisted spray deposition technique to fabricate quantum dot (QD)-based LSCs (QD-LSCs). This method allows for the production of high-performance QD-LSCs with different device dimensions and geometries. In addition, the quality of the QD thin-film coating layer is relatively independent of the concentration and volume of the coating QD ink solution, allowing for deliberate programming and performance optimization of the resulting QD-LSC devices. We anticipate that this ultrasonic spray coating method can be widely applied to the manufacturing of high-quality LSC devices that are integrable to various applications.

8.
Int J Biol Macromol ; 194: 644-653, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34822832

RESUMO

The healing of defected skin tissue is a complex process, especially for chronic wounds. Poor healing of these wounds may cause extensive suffering and high cost for patients. Traditional wound dressings are typically designed for a single function and they cannot satisfy all requirements for the whole process of wound healing. Therefore, it is necessary to develop new types of wound dressings with multiple functions for wound healing. In particular, adding an antibacterial function has been shown to be of great benefit during tissue repair. Nano­silver is widely used in wound treatment because of various advantages, such as its wide antibacterial spectrum and lower drug resistance. Therefore, wound dressings loaded with nano­silver have attracted widespread attention in wound healing. Naturally derived polysaccharides hold great potential as wound dressings, because of their abundant availability, low prices and good biocompatibility. In this review, nano­silver functionalized polysaccharide-based wound dressings are systematically reviewed, including their preparation methods, antibacterial performances and classification of nano­silver wound dressings. Moreover, the toxicity of nano­silver based wound dressings is discussed and the prospective research direction is elaborated. This review aims to provide readers with an overview of the latest developments in silver nanotechnology, and to provide a little guidance for the research of nano­silver functionalized polysaccharide-based wound dressings.


Assuntos
Antibacterianos/química , Nanotecnologia/métodos , Polissacarídeos/química , Prata/química , Cicatrização , Animais , Bandagens , Humanos
9.
J Phys Chem Lett ; 12(30): 7180-7193, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34309389

RESUMO

Quantum dots (QDs) with tunable photo-optical properties and colloidal nature are ideal for a wide range of photocatalytic reactions. In particular, QD photocatalysts for organic transformations can provide new and effective synthetic routes to high value-added molecules under mild conditions. In this Perspective, we discuss the advances of employing QDs for visible-light-driven organic transformations categorized into net reductive reactions, net oxidative reactions, and redox neutral reactions. We then provide our outlook for potential future directions in the field: nanostructure engineering to improve charge separation efficiencies, ligand shell engineering to optimize overall catalyst performance, in situ comprehensive studies to delineate underlying reaction mechanisms, and laboratory automation with the assistance of modern computing techniques to revolutionize the reaction optimization process.

10.
Nano Lett ; 21(4): 1620-1627, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33570415

RESUMO

Morphology control represents an important strategy for the development of functional nanomaterials and has yet to be achieved in the case of promising lead-free double perovskite materials so far. In this work, high-quality Cs2AgBiX6 (X = Cl, Br, I) two-dimensional nanoplatelets were synthesized through a newly developed synthetic procedure. By analyzing the optical, morphological, and structural evolutions of the samples during synthesis, we elucidated that the growth mechanism of lead-free double perovskite nanoplatelets followed a lateral growth process from mono-octahedral-layer (half-unit-cell in thickness) cluster-based nanosheets to multilayer (three to four unit cells in thickness) nanoplatelets. Furthermore, we demonstrated that Cs2AgBiBr6 nanoplatelets possess a better performance in photocatalytic CO2 reduction compared with their nanocube counterpart. Our work demonstrates the first example with two-dimensional morphology of this important class of lead-free perovskite materials, shedding light on the synthetic manipulation and the application integration of such promising materials.

11.
Cell Metab ; 33(3): 547-564.e7, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33357458

RESUMO

In response to cold exposure, thermogenic adipocytes internalize large amounts of fatty acids after lipoprotein lipase-mediated hydrolysis of triglyceride-rich lipoproteins (TRL) in the capillary lumen of brown adipose tissue (BAT) and white adipose tissue (WAT). Here, we show that in cold-exposed mice, vascular endothelial cells in adipose tissues endocytose substantial amounts of entire TRL particles. These lipoproteins subsequently follow the endosomal-lysosomal pathway, where they undergo lysosomal acid lipase (LAL)-mediated processing. Endothelial cell-specific LAL deficiency results in impaired thermogenic capacity as a consequence of reduced recruitment of brown and brite/beige adipocytes. Mechanistically, TRL processing by LAL induces proliferation of endothelial cells and adipocyte precursors via beta-oxidation-dependent production of reactive oxygen species, which in turn stimulates hypoxia-inducible factor-1α-dependent proliferative responses. In conclusion, this study demonstrates a physiological role for TRL particle uptake into BAT and WAT and establishes endothelial lipoprotein processing as an important determinant of adipose tissue remodeling during thermogenic adaptation.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Lipoproteínas/metabolismo , Lisossomos/metabolismo , Termogênese , Triglicerídeos/metabolismo , Adiponectina/genética , Adiponectina/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/patologia , Animais , Antígenos CD36/metabolismo , Diferenciação Celular , Proliferação de Células , Temperatura Baixa , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lipoproteínas/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Espécies Reativas de Oxigênio/metabolismo , Receptores de Lipoproteínas/genética , Receptores de Lipoproteínas/metabolismo , Esterol Esterase/deficiência , Esterol Esterase/genética , Esterol Esterase/metabolismo , Triglicerídeos/genética
12.
Adv Sci (Weinh) ; 7(18): 2001317, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32999842

RESUMO

Doping metal ions into lead halide perovskite nanocrystals (NCs) has attracted great attention over the past few years due to the emergence of novel properties relevant to optoelectronic applications. Here, the synthesis of Mn2+/Yb3+ codoped CsPbCl3 NCs through a hot-injection technique is reported. The resulting NCs show a unique triple-wavelength emission covering ultraviolet/blue, visible, and near-infrared regions. By optimizing the dopant concentrations, the total photoluminescence quantum yield (PL QY) of the codoped NCs can reach ≈125.3% due to quantum cutting effects. Mechanism studies reveal the efficient energy transfer processes from host NCs to Mn2+ and Yb3+ dopant ions, as well as a possible inter-dopant energy transfer from Mn2+ to Yb3+ ion centers. Owing to the high PL QYs and minimal reabsorption loss, the codoped perovskite NCs are demonstrated to be used as efficient emitters in luminescent solar concentrators, with greatly enhanced external optical efficiency compared to that of using solely Mn2+ doped CsPbCl3 NCs. This study presents a new model system for enriching doping chemistry studies and future applications of perovskite NCs.

13.
Angew Chem Int Ed Engl ; 59(50): 22563-22569, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-32852841

RESUMO

Semiconductor quantum dots (QDs) have attracted tremendous attention in the field of photocatalysis, owing to their superior optoelectronic properties for photocatalytic reactions, including high absorption coefficients and long photogenerated carrier lifetimes. Herein, by choosing 2-(3,4-dimethoxyphenyl)-3-oxobutanenitrile as a model substrate, we demonstrate that the stereoselective (>99 %) C-C oxidative coupling reaction can be realized with a high product yield (99 %) using zwitterionic ligand capped CsPbBr3 perovskite QDs under visible light illumination. The reaction can be generalized to different starting materials with various substituents on the phenyl ring and varied functional moieties, producing stereoselective dl-isomers. A radical mediated reaction pathway has been proposed. Our study provides a new way of stereoselective C-C oxidative coupling via a photocatalytic means using specially designed perovskite QDs.

14.
Anal Chem ; 92(7): 5346-5353, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32126174

RESUMO

Reliable quantification of the optical properties of fluorescent quantum dots (QDs) is critical for their photochemical, -physical, and -biological applications. Presented herein is the experimental quantification of photon scattering, absorption, and on-resonance-fluorescence (ORF) activities of CdSe/CdS core/shell fluorescent QDs as a function of the shell sizes and geometries. Four spherical QDs (SQDs) with different diameters and four rod-like QDs (RQDs) with different aspect ratios (ARs) have been analyzed using UV-vis, fluorescence, and the recent polarized resonance synchronous spectroscopic (PRS2) methods. All quantum dots are simultaneous absorbers and scatterers in the UV-vis wavelength region, and they all exhibit strong ORF emission in the wavelength regions where the QDs both absorb and emit. The absorption and scattering cross-sections of the CdS shell are linearly and quadratically, respectively, proportional to the shell volume for both the SQDs and RQDs. However, the effects of CdS shell coating on the core optical properties are different between SQDs and RQDs. For RQDs, increasing the CdS shell volume through the length elongation has no effect on either the peak wavelength or intensity of the CdSe core UV-vis absorption and ORF, but it reduces the QD fluorescence depolarization. In contrast, increasing CdS shell volume in the SQDs induces red-shift in the CdSe core peak UV-vis absorption and ORF wavelengths, and increases their peak cross-sections, but it has no effect on the SQD fluorescence depolarization. The RQD ORF cross-sections and quantum yields are significantly higher than their respective counterparts for the SQDs with similar particle sizes (volumes). While these new insights should be significant for the QD design, characterization, and applications, the methodology presented in this work is directly applicable for quantifying the optical activities of optically complex materials where the common UV-vis spectrometry and fluorescence spectroscopy are inadequate.

15.
Anal Chem ; 91(13): 8540-8548, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31134802

RESUMO

Optical properties of fluorescent materials including their UV-vis absorption, scattering, and on-resonance fluorescence activities are strongly wavelength-dependent. Reported herein is a divide-and-conquer strategy for experimental quantification of fundamental optical constants of fluorescent nanomaterials including their UV-vis absorption, scattering, and on-resonance-fluorescence (ORF) cross-section spectra and ORF fluorescence and light scattering depolarization spectra. The fluorophore UV-vis extinction spectrum is first divided into a blue and a red wavelength region. The UV-vis extinction cross-section spectrum in the blue wavelength region is decomposed into its absorption and scattering extinction spectra straightforwardly using the established polarized resonance synchronous spectroscopic technique. In its red wavelength region, however, the fluorophores can be simultaneous photon absorbers, scatterers, and anti-Stokes-shifted, on-resonance, and Stokes-shifted fluorescence emitters under the resonance excitation and detection conditions. A polarized anti-Stokes'-shifted, on-resonance, and Stokes'-shifted spectroscopic method is developed for quantifying fluorophore absorption, scattering, one-resonance fluorescence (ORF) cross-section spectra, and scattering and ORF fluorescence depolarization spectra in this wavelength region. Example applications of the presented techniques were demonstrated with fluorescent polystyrene nanoparticles, fluorescent quantum dots, and molecular fluorophores Rhodamine 6G and Eosin Y.

16.
Front Chem ; 7: 145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30949473

RESUMO

Dynamic materials have been given an increased amount of attention in recent years with an expectation that they may exhibit properties on demand. Especially, the combination of fluorescent quantum dots (QDs) and light-responsive organic switches can generate novel photo-switchable materials for diverse applications. In this work, a highly reversible dynamic hybrid system is established by mixing dual-color emitting Mn-doped CdS-ZnS quantum dots (QDs) with photo-switchable diarylethene molecules. We show that the diarylethene 1,2-bis(5-(3,5-bis(trifluoromethyl)phenyl)-2-methylthiophen-3-yl)cyclopent-1-ene (switch molecule 1) performs fabulous photo-switching property (between its open, 1o and closed, 1c forms), and high fatigue resistance in this hybrid system. The emission color switching between blue and pink of the system can be induced mainly by selective quenching/recovering of the Mn- photoluminescence (PL) of the QDs due to the switchable absorbance of the molecule 1. Mechanistic studies show that quenching of QD emission following UV illumination was caused by both Förster resonance energy transfer (FRET) and reabsorption by surrounding 1c molecules in the case of the Mn-PL, and solely by reabsorption in the case of badngap- (BG-)PL. This photo-switchable system could be potentially used in applications ranging from self-erasing paper to super-resolution fluorescence imaging.

17.
Cell Metab ; 28(4): 644-655.e4, 2018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30033199

RESUMO

The coordination of the organ-specific responses regulating systemic energy distribution to replenish lipid stores in acutely activated brown adipose tissue (BAT) remains elusive. Here, we show that short-term cold exposure or acute ß3-adrenergic receptor (ß3AR) stimulation results in secretion of the anabolic hormone insulin. This process is diminished in adipocyte-specific Atgl-/- mice, indicating that lipolysis in white adipose tissue (WAT) promotes insulin secretion. Inhibition of pancreatic ß cells abolished uptake of lipids delivered by triglyceride-rich lipoproteins into activated BAT. Both increased lipid uptake into BAT and whole-body energy expenditure in response to ß3AR stimulation were blunted in mice treated with the insulin receptor antagonist S961 or lacking the insulin receptor in brown adipocytes. In conclusion, we introduce the concept that acute cold and ß3AR stimulation trigger a systemic response involving WAT, ß cells, and BAT, which is essential for insulin-dependent fuel uptake and adaptive thermogenesis.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Temperatura Baixa , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Lipólise/fisiologia , Receptores Adrenérgicos beta 3/metabolismo , Adipócitos Marrons/metabolismo , Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Animais , Dieta Hiperlipídica , Dioxóis/farmacologia , Metabolismo Energético/fisiologia , Lipase/metabolismo , Lipoproteínas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptídeos/farmacologia , Receptor de Insulina/antagonistas & inibidores , Termogênese/fisiologia , Triglicerídeos/metabolismo
18.
Nano Lett ; 18(8): 5049-5056, 2018 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-29989818

RESUMO

The self-assembly of nanocrystals into ordered superlattices is a powerful strategy for the production of functional nanomaterials. The assembly of well-ordered target structures, however, requires control over the building blocks' size and shape as well as their interactions. While nanocrystals with homogeneous composition are now routinely synthesized with high precision and assembled into various ordered structures, high-quality multicomponent nanocrystals and their ordered assemblies are rarely reported. In this paper, we demonstrate the synthesis of quantum dot-gold (QD-Au) heterodimers. These heterodimers possess a uniform shape and narrow size distribution and are capped with oleylamine and dodecyltrimethylammonium bromide (DTAB). Assembly of the heterodimers results in a superlattice with long-range orientational alignment of dimers. Using synchrotron-based X-ray measurements, we characterize the complex superstructure formed from the dimers. Molecular dynamics simulations of a coarse-grained model suggest that anisotropic interactions between the quantum dot and gold components of the dimer drive superlattice formation. The high degree of orientational order demonstrated in this work is a potential route to nanomaterials with useful optoelectronic properties.

19.
Org Lett ; 16(20): 5410-3, 2014 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-25285730

RESUMO

A metal-free cross-coupling of enamines and electron-deficient amines through oxidative C(sp(2))-N bond formation has been realized by using TBAI as catalyst and TBHP as oxidant. This novel strategy allows for an efficient organocatalytic synthesis of the synthetically useful diaminoalkene derivatives and is highlighted by appealing features such as readily available of the starting materials, wide substrate scope and transition-metal-free characteristics.

20.
J Org Chem ; 79(16): 7451-8, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25068595

RESUMO

A metal-free protocol for direct aryl-aldehyde Csp(2)-Csp(2) bond formation via a PhI(OAc)2-mediated intramolecular cross-dehydrogenative coupling (CDC) of various 2-(N-arylamino)aldehydes was developed. The novel methodology requires no need of preactivation of the aldehyde group, is applicable to a large variety of functionalized substrates, and most of all provides a convenient approach to the construction of biologically important acridone derivatives.

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