Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
J Org Chem ; 85(5): 3963-3972, 2020 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-32037828

RESUMEN

A novel visible-light photoredox catalysis protocol for the effective and efficient synthesis of 3-substituted chroman-4-ones and 2,3-dihydroquinolin-4(1H)-ones via tandem radical addition/cyclization of alkenyl aldehydes has been described. This reaction features a broad substrate scope, mild reaction conditions, and good functional group tolerance character.

2.
Sensors (Basel) ; 20(18)2020 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-32961737

RESUMEN

Characterizing the surface deformation during the inter-survey period could assist in understanding rock mass progressive failure processes. Moreover, 3D reconstruction of rock mass surface is a crucial step in surface deformation detection. This study presents a method to reconstruct the rock mass surface at close range in a fast way using the improved structure from motion-multi view stereo (SfM) algorithm for surface deformation detection. To adapt the unique feature of rock mass surface, the AKAZE algorithm with the best performance in rock mass feature detection is introduced to improve SfM. The surface reconstructing procedure mainly consists of image acquisition, feature point detection, sparse reconstruction, and dense reconstruction. Hereafter, the proposed method was verified by three experiments. Experiment 1 showed that this method effectively reconstructed the rock mass model. Experiment 2 proved the advanced accuracy of the improved SfM compared with the traditional one in reconstructing the rock mass surface. Eventually, in Experiment 3, the surface deformation of rock mass was quantified through reconstructing images before and after the disturbance. All results have shown that the proposed method could provide reliable information in rock mass surface reconstruction and deformation detection.

3.
Chemistry ; 20(17): 4885-90, 2014 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-24648263

RESUMEN

The syntheses and structures of two new Zn(II) complexes, a 2D graphite-like layer {[Zn(PIA)H2 O]⋅H2 O}n (1) and an independent 1D single-walled metal-organic nanotube (SWMONT) {[Zn2 (PIA)2 (bpy)2 ]⋅2.5 H2 O⋅DMA}n (2), have been reported based on a "Y"-shaped 5-(pyridine-4-yl)isophthalic acid ligand (H2 PIA). Interestingly, the 2D graphite-like layer in 1 can transform into the independent 1D SWMONT in 2 with addition of 2,2'-bipyridine (bpy), which represents the first successfully experimental example of an independent 1D metal-organic nanotube generated from a 2D layer by a "rolling-up" mechanism.

4.
J Neural Transm (Vienna) ; 121(2): 123-34, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24057652

RESUMEN

Parkinson's disease (PD) is a chronic neurodegenerative disorder affecting older individuals. There is inconsistent evidence about the prevalence and incidence of PD in China at present. The aim of the meta-analysis was to estimate the prevalence and incidence of PD and its relation to age, gender, and stage in China. The literature search was conducted using PubMed, EMBASE, Chinese Biological Medical Literature database (CBM), Chinese National Knowledge Infrastructure database (CNKI), Chinese Wanfang and Chongqing VIP database for studies investigating the prevalence and incidence of PD in China from the commencement of the database until August 2012; both English and Chinese publications were included. We estimated the prevalence and incidence of PD using meta-analysis. Thirteen eligible articles were collected. The results showed that the pooled prevalence and incidence of PD were 2 per 100,000 population and 797 per 100,000 person-years. A higher prevalence of PD was found in males than in females (OR 1.29, 95 % CI 1.05-1.57). The prevalence of PD increased with age: the highest was 1,663 per 100,000 in those aged 80 and older. The overall prevalence of PD is lower in China than in developed countries, but the incidence is higher than in some developed countries. Overall, the prevalence of PD appears to increase with age and there are sex differences evident in Chinese individuals.


Asunto(s)
Enfermedad de Parkinson/epidemiología , China/epidemiología , Femenino , Humanos , Incidencia , Masculino , Prevalencia
5.
Chem Commun (Camb) ; 59(23): 3463-3466, 2023 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-36872868

RESUMEN

Heterocyclic Quaternary Phosphonium Salts (HQPS) have emerged as promising chemicals for organic synthesis and medicinal chemistry. However, the present synthetic methodology of this type of compound is still limited. Here, we report a deconstructive reorganization strategy based on Brønsted acid-mediated tandem 1,4 addition/intramolecular cyclization of triphenylphosphine derivatives and in situ generated o-AQMs for the first time. This protocol provides a novel approach to heterocyclic quaternary phosphonium salts. The method also features a non-metal catalyst, mild reaction conditions, high efficiency and wide substrate scope. Moreover, a series of obtained heterocyclic phosphonium salts can be converted to isotopically labelled 2-benzofuran compounds directly by simple deuteration reactions.

6.
Front Neurol ; 14: 1065484, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37122311

RESUMEN

Objective: To investigate the effect of two major etiologies [intracranial atherosclerotic stenosis (ICAS) and cardioembolism (CE])] on outcomes of acute ischemic stroke (AIS) patients due to large vessel occlusion (LVO) after endovascular thrombectomy (EVT). Methods: Anterior circulation AIS patients receiving EVT were retrospectively analyzed. Clinical and laboratory data were collected. Clinical outcomes including favorable outcome (90-day modified Rankin Scale 0-2), mortality, intracranial hemorrhage (ICH) and symptomatic ICH (sICH) were compared. A systematic review and meta-analysis was also performed. Results: A total of 302 AIS patients were included and divided into the ICAS group (86 patients) and the CE group (216 patients). Patients in the ICAS group were younger (62[18.0] vs. 68[19.0] years, p < 0.001), more likely to have smoking (52.3% vs. 26.9%, p < 0.001) and drinking (52.3% vs. 23.1%, p < 0.001) history, and more frequently required rescue therapy (80.2% vs. 4.6%, p < 0.001) compared to the CE group. However, favorable outcome (aOR 0.722, 95%CI 0.372-1.402, p = 0.336) and mortality (aOR 1.522, 95%CI 0.606-3.831, p = 0.371) were not significantly different between the two groups before and after adjustment. The incidence of sICH and ICH were comparable between the two groups before and after adjustment. Systematic review and meta-analysis consisted of 8 eligible studies (7 previous studies and this current study), incorporating 552 ICAS patients and 1,402 CE patients. Favorable outcome was slightly more likely in the ICAS group compared to the CE group (54.2% vs. 46.3%, OR 1.40, 95%CI 1.00-1.96, I 2 = 53.2%). Moreover, the ICAS group had a lower rate of mortality (14.3% vs. 22.2%, OR 0.63, 95%CI 0.46-0.87, I 2 = 0.0%) and ICH (19.5% vs. 31.9%, OR 0.60, 95%CI 0.42-0.84, I 2 = 0.0%) than the CE group, while the two groups were similar in sICH rate (5.9% vs. 6.7%, OR 0.94, 95%CI 0.55-1.60, I 2 = 6.3%). Conclusion: Etiology was not considered as an important factor in functional outcome, despite the differences in baseline characteristics and technical EVT approach. The current study of anterior circulation AIS-LVO patients supports that outcomes for those with ICAS are not significantly different from those with CE.

7.
Materials (Basel) ; 15(20)2022 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-36295336

RESUMEN

Samples of (110), (100), and (111) MgO single crystals were implanted with 70 keV N ions at room temperature. All as-implanted samples showed room temperature hysteresis in magnetization loops. The observed saturation magnetization (Ms) was 0.79 × 10−4 emu/g, 1.28 × 10−4 emu/g, and 1.5 × 10−4 emu/g for (110), (100) and (111) orientation implanted-MgO and follows the relation Ms(111) > Ms(100) > Ms(110), indicative of crystalline orientation-dependent ferromagnetism in N-implanted MgO. The samples were characterized by X-ray photoelectron spectroscopy (XPS), high resolution X-ray diffraction (HRXRD), reciprocal space mapping (RSM), and photoluminescence (PL). The results indicated that the amount of N-substitute-O and N-interstitial defects in these three N-implanted MgO samples showed the same changing tendency as compared with Ms data. Thus, we conclude that the N-substitute-O and N-interstitial defects may play a crucial role in controlling the N+-implanted-induced ferromagnetism.

8.
RSC Adv ; 12(41): 26945-26952, 2022 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-36320831

RESUMEN

In this work, a luminescent metal-organic framework (Eu-MOF {[Eu6L6(µ3-OH)8(H2O)3]8·H2O} n ) was constructed by a solvothermal method with a linear organic ligand L (10-[(2-amino-4-carboxyl-phenyl)ethynyl]anthracene-9-carboxylic acid) based on anthracene and alkyne groups and using Eu3+ as the metal center. The MOF exhibits a stable UiO-66 crystal structure, and a six-core cluster twelve-linked secondary structural unit was successfully synthesized using 2-fluorobenzoic acid as a modulator, forming a classical fcu topology. Moreover, it exhibits good chemical stability. Interestingly, Eu-MOF exhibited high selectivity and sensitive fluorescence burst properties towards Fe3+ ions and 2,4,6-trinitrophenol (TNP) in DMF solution. For Fe3+, the K SV value is 5.06 × 105 M-1 and the LOD value is 5.1 × 10-7 M. For TNP, the K SV value is 1.92 × 104 M-1 and the LOD value is 1.93 × 10-6 M. In addition, Eu-MOF showed good anti-interference ability and fast response. This work provides an excellent fluorescent sensor for the detection of Fe3+ and 2,4,6-trinitrophenol (TNP) residues in contaminants.

9.
Dalton Trans ; 51(29): 11125-11134, 2022 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-35797528

RESUMEN

The active sites of [FeFe]-hydrogenase promoted by Fe/E (E = S, Se) clusters have attracted considerable interest due to their significance in understanding the interconversion of hydrogen with protons and electrons. As an extension of the study on Fe/Se clusters related to H-cluster model compounds of [FeFe]-hydrogenase, a series of tertiary phosphine substituted Fe/Se carbonyls were successfully prepared. The treatment of Fe2(µ-SePh)2(CO)6 (A) and excess PR3 resulted in the ferrous bis(selenolate) carbonyls Fe(SePh)2(CO)2(PR3)2 (PR3 = PPhMe2, 1; PMe3, 2) in moderate yields. In striking contrast, the reaction of Fe2(µ-SeCH2Ph)2(CO)6 (B) with the same PR3 ligand resulted in the PR3-disubstituted models Fe2(µ-SeCH2Ph)2(CO)4(PR3)2 (PR3 = PPhMe2, 3; PMe3, 4) as the principal products. The more interesting finding is that two independent isomers (anti- and syn-) can be isolated according to different reaction temperatures. Further reactions of 3 or 4 with PR3 under UV irradiation afforded the first PR3-trisubstituted 2Fe2Se derivatives Fe2(µ-SeCH2Ph)2(CO)3(PR3)3 (PR3 = PPhMe2, 5; PMe3, 6). 6 could be further converted into the tetrasubstituted product Fe2(µ-SeCH2Ph)2(CO)2(PMe3)4 (7), while no further substitution was observed with 5 and excess of PPhMe2. All the prepared compounds were fully characterized by elemental analysis, various spectroscopic techniques and X-ray crystallography. In addition, some electrochemical properties of these models were studied by cyclic voltammetry (CV) in MeCN. Compounds 4, 6 and 7 were found to be catalysts for the H2 evolution reaction under electrochemical conditions.


Asunto(s)
Hidrogenasas , Proteínas Hierro-Azufre , Cristalografía por Rayos X , Hidrógeno/química , Hidrogenasas/química , Proteínas Hierro-Azufre/química , Modelos Moleculares , Protones
10.
Curr Med Sci ; 42(1): 39-47, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35122611

RESUMEN

OBJECTIVE: Angelica (A.) sinensis is used as a traditional medical herb for the treatment of neurodegeneration, aging, and inflammation in Asia. A. sinensis optimal formula (AOF) is the best combination in A. sinensis that has been screened to rescue the cognitive ability in ß-amyloid peptide (Aß25-35)-treated Alzheimer's disease (AD) rats. The objective of this study was to investigate the effect of AOF on the learning and memory of AD rats as well as to explore the underlying mechanisms. METHODS: Male Wistar rats were infused with Aß25-35 for AD model induction or saline (negative control). Five groups of AD rats were fed on AOF at 20, 40, or 80 mL/kg every day, donepezil at 0.9 mg/kg every day (positive control), or an equal volume of water (AD model) intragastrically once a day for 4 weeks, while the negative control rats were fed on water. The Morris water maze test was used to evaluate the cognitive function of the rats. The Aß accumulation, cholinergic levels, and antioxidative ability were detected by ELISA. Additionally, the candidate mechanism was determined by gene sequencing and quantitative real-time polymerase chain reaction. RESULTS: The results showed that AOF administration significantly ameliorated Aß25-35-induced memory impairment. AOF decreased the levels of amyloid-ß precursor protein and Aß in the hippocampus, rescued the cholinergic levels, increased the activity of superoxide dismutase, and decreased the malondialdehyde level. In addition, AOF inhibited the expression of IL1b, Mpo, and Prkcg in the hippocampus. CONCLUSION: These experimental findings illustrate that AOF prevents the decrease in cognitive function and Aß deposits in Aß25-35-treated rats via modulating neuroinflammation and oxidative stress, thus highlighting a potential therapeutic avenue to promote the co-administration of formulas that act on different nodes to maximize beneficial effects and minimize negative side effects.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/farmacología , Angelica sinensis , Trastornos de la Memoria/tratamiento farmacológico , Enfermedades Neuroinflamatorias/tratamiento farmacológico , Nootrópicos/farmacología , Estrés Oxidativo/efectos de los fármacos , Preparaciones de Plantas/farmacología , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/inmunología , Enfermedad de Alzheimer/metabolismo , Animales , Modelos Animales de Enfermedad , Masculino , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/inmunología , Trastornos de la Memoria/metabolismo , Enfermedades Neuroinflamatorias/inducido químicamente , Enfermedades Neuroinflamatorias/inmunología , Enfermedades Neuroinflamatorias/metabolismo , Nootrópicos/administración & dosificación , Preparaciones de Plantas/administración & dosificación , Ratas , Ratas Wistar
11.
Artículo en Inglés | MEDLINE | ID: mdl-35010428

RESUMEN

Blood flow restriction training (BFRT) is a new method for promoting muscle growth and improving muscle function, even with relatively low-intensity exercise. BFRT on patients with obesity has not been extensively studied. This study aimed to analyze the effects of cycling at 40% of maximum oxygen uptake (VO2max) combined with BFRT on body composition and serum biomarkers among college students with obesity. This pilot study included thirty-seven male college students with obesity aged 18-22 years (experimental group (EG): n = 18; control group (CG): n = 19). The EG conducted 40% VO2max cycling combined with BFRT activities and the CG conducted 40% VO2max cycling without BFRT two times per week for 12 weeks. Our results showed that in EG, there were significant differences in weight, thigh skinfold thickness (TS), waist circumference, abdominal skinfold thickness, fat mass, body fat percentage, body mass index and glucose (GLU), total cholesterol (TC), triglyceride, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels before and after the experiment (p < 0.05, p < 0.01, and p < 0.001). After the experiment, TS, GLU, TC, HDL-C, and LDL-C in EG were significantly different than those of the CG (p < 0.05, p < 0.01, and p < 0.001). Together, our results demonstrate that cycling at 40% VO2max combined with BFRT may improve body composition and blood lipid profile of male college students with obesity. Our findings have important implications for those who cannot perform moderate- and high-intensity exercises.


Asunto(s)
Terapia de Restricción del Flujo Sanguíneo , Consumo de Oxígeno , Biomarcadores , Composición Corporal , China , Humanos , Masculino , Obesidad , Oxígeno , Proyectos Piloto , Estudiantes
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 254: 119636, 2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-33751996

RESUMEN

A series of Dy3+ doped Na0.5Bi0.5TiO3 (NBT: xDy3+, x = 0.003-0.018) lead-free ferroelectric ceramics were successfully prepared by a solid-state reaction method. The Dy3+ ions composition dependent photoluminescence properties were systematically studied. All the samples display intense characteristic emission of Dy3+ under an excitation wavelength of 454 nm, which are attributed to the transitions of 4F9/2 → 6HJ/2 (J = 13, 11 and 9). All the samples show strong orange-yellow emission, which could be applied to warm white light hopefully. When the content of Dy3+ is equal to 0.012, the ceramic has the optimal luminous performance. Remarkable thermal quenching of the luminous intensity ceramic occurs as the temperature is higher than initial temperature 293 K. Furthermore, Dy3+ activated photoluminescence performance combined with the presence of ferroelectricity in the NBT host can be applied to developing non-contact optical temperature sensitive materials and other future novel optoelectronic devices.

13.
Inorg Chem ; 49(23): 10781-7, 2010 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-21028893

RESUMEN

A series of 3-D lanthanide porous coordination polymers, [Ln(6)(BDC)(9)(DMF)(6)(H(2)O)(3)·3DMF](n) [Ln = La, 1; Ce, 2; Nd, 3], [Ln(2)(BDC)(3)(DMF)(2)(H(2)O)(2)](n) [Ln = Y, 4; Dy, 5; Eu, 6], [Ln(2)(ADB)(3)(DMSO)(4)·6DMSO·8H(2)O](n) [Ln = Ce, 7; Sm, 8; Eu, 9; Gd, 10], {[Ce(3)(ADB)(3)(HADB)(3)]·30DMSO·29H(2)O}(n) (11), and [Ce(2)(ADB)(3)(H(2)O)(3)](n) (12) (H(2)BDC = benzene-1,4-dicarboxylic acid and H(2)ADB = 4,4'-azodibenzoic acid), have been synthesized and characterized. In 1-3, the adjacent Ln(III) ions are intraconnected to form 1-D metal-carboxylate oxygen chain-shaped building units, [Ln(4)(CO(2))(12)](n), that constructed a 3-D framework with 4 × 7 Å rhombic channels. In 4-6, the dimeric Ln(III) ions are interlinked to yield scaffolds with 3-D interconnecting tunnels. Compounds 7-10 are all 3-D interpenetrating structures with the CaB6-type topology structure. Compound 11 is constructed by ADB spacers and trinulcear Ce nodes with a NaCl-type topology structure and a 1.9-nm open channel system. In 12, the adjacent Ce(III) ions are intraconnected to form 1-D metal-carboxylate oxygen chain-shaped building units, [Ln(4)(CO(2))(12)](n), and give rise to a 3-D framework. Moreover, 6 exhibits characteristic red luminescence properties of Eu(III) complexes. The magnetic susceptibilities, over a temperature range of 1.8-300 K, of 3, 6, and 7 have also been investigated; the results show paramagnetic properties.

14.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 9): m1174, 2010 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-21588562

RESUMEN

The asymmetric unit of the title complex, [Sn(CH(3))(2)(C(6)H(7)N(2)S)(2)], contains two independent mol-ecules with similar configurations. In each, the Sn(IV) cation is coordinated by two methyl and two 4,6-dimethyl-pyrimidine-2-thiol-ate anions in a distorted SnS(2)C(2) tetra-hedral geometry. In the two mol-ecules, the S-Sn-S bond angles are 87.70 (5) and 88.93 (4)°, while the C-Sn-C bond angles are 125.7 (3) and 125.9 (2)°. Weak C-H⋯N hydrogen bonding is present in the crystal structure.

15.
Dalton Trans ; 49(17): 5581-5589, 2020 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-32271339

RESUMEN

Sm3+-Modified (1 -x)Na0.5Bi0.5TiO3-xCaTiO3 (NBT-xCT:Sm3+) piezo-luminescent ceramic materials were synthesized to investigate the influence of CaTiO3 (CT) concentration on their photoluminescence and electrical performance. Under 480 nm irradiation, the NBT-xCT:Sm3+ samples exhibit prominent orange-red emission, with a prime emission peak centered at 597 nm. A moderate amount of CT doping in the Sm3+-modified NBT ceramics boosts both their photoluminescence and piezoelectric properties significantly, with NBT-0.04CT:Sm3+ showing the optimal performance. Furthermore, outstanding luminescence thermal stability over a temperature range of 293-473 K and superior water resistance behavior are achieved in the NBT-0.04CT:Sm3+ ceramic. These results indicate that NBT-xCT:Sm3+ piezo-luminescent ceramics show great potential applications in white LEDs, as well as novel optical-electronic multifunctional devices.

16.
J Inorg Biochem ; 206: 111022, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32070916

RESUMEN

Six novel organotin phosphonate complexes, [(Me3Sn)4(HL1)4]n1, [(Me3Sn)2(HL2)2]n2, [(Me3Sn)2L3(H2O)]n3, [(Ph3Sn)(HL1)]64, [(Ph3Sn)2L2]n5 and [(Ph3Sn)2L3]66, derived from phosphonic acid ligands [NaHL1 = 1-C10H7OPO2(OH)Na, H2L2 = 1-C10H7PO(OH)2, H2L3 = 2-C10H7PO(OH)2], have been synthesized and characterized by elemental analysis, FT-IR, NMR (1H, 13C, 31P and 119Sn) spectroscopy and X-ray crystallography. The structural analysis reveals that complexes 1 and 5 display 1D infinite zig-zag chain structures, and complex 2 shows 1D right-handed helical chain structure, while complex 3 displays 1D left-handed helical chain structure. Complexes 4 and 6 are 24-membered macrocyclic rings interconnected by P, O and Sn atoms. Additionally, the molecules of complexes 1 and 3 are further linked through intermolecular π···π and O-H···O interaction into supramolecular structures, respectively. Furthermore, we preliminarily estimated in vitro cytostatic activity of complexes 1-6 against the human cervix tumor cells (HeLa), human hepatocellular carcinoma cells (HepG-2) and human normal breast cells (HBL-100). Importantly, the anti-proliferative properties and possible pathway of complex 6 are investigated, and the results demonstrate that complex 6 could induce apoptotic cell death via an overload of intracellular reactive oxygen species (ROS) levels and the dysfunctional depolarization of mitochondrial membranes.


Asunto(s)
Citostáticos/química , Citostáticos/farmacología , Compuestos Orgánicos de Estaño/química , Compuestos Orgánicos de Estaño/farmacología , Ácidos Fosforosos/química , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Citostáticos/síntesis química , Femenino , Células HeLa , Humanos , Ligandos , Neoplasias Hepáticas/patología , Espectroscopía de Resonancia Magnética , Masculino , Estructura Molecular , Compuestos Orgánicos de Estaño/síntesis química , Ácidos Fosforosos/farmacología , Especies Reactivas de Oxígeno/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Estaño/química , Neoplasias del Cuello Uterino/patología
17.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 9): m1030, 2009 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-21577397

RESUMEN

In the title compound, [Sn(CH(3))(2)(C(3)H(3)N(2)S(3))(2)], the Sn(IV) atom is coordinated within a C(2)N(2)S(2) donor set that defines a skew-trapezoidal bipyramidal geometry in which the methyl groups lie over the weakly coordinated N atoms. Two independent mol-ecules comprise the asymmetric unit, each of which lies on a mirror plane that passes through the C(2)Sn unit.

18.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 1): m15, 2009 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-21579916

RESUMEN

The crystal structure of the title compound, [Na(C(3)H(3)N(2)S(3))(H(2)O)(2)](n), features polymeric chains made up of O⋯O edge-shared NaSN(H(2)O)(4) units running along the b axis. The Na(+) ion and all non-H atoms of the thia-diazole ligand lie on a mirror plane.

19.
Org Lett ; 21(2): 465-468, 2019 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-30618260

RESUMEN

A novel Lewis base-catalyzed [4 + 3] annulation process for the construction of benzo[ b]oxepine scaffolds has been developed. 1,4-Diazabicyclo[2.2.2]octane (DABCO) promotes the union of o-QMs and Morita-Baylis-Hillman carbonates in reasonable to excellent yields and good stereoselectivities (dr > 20:1). This straightforward, catalytic approach offers access to a variety of synthetically useful benzo[ b]oxepine derivatives bearing oxindole scaffolds containing all-carbon spiro-quaternary stereocenters.

20.
Inorg Chem ; 47(16): 7060-1, 2008 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-18620388

RESUMEN

The reaction of 1-(4-carboxyphenyl)-5-mercapto-1 H-tetrazole with trimethyltin chloride in the presence of sodium ethoxide in benzene affords a novel 2D organotin network structure complex 1, which is an unusual organotin network containing a hexanuclear 60-membered organotin macrocycle. The complex has been characterized by elemental analysis, IR, and (1)H, (13)C, and (119)Sn NMR spectroscopy. Furthermore, we have also characterized the complex by X-ray crystallography.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA