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71.
[reaction: see text] Ortho-lithiation of (2R,4S,5R)-3,4-dimethyl-2-ferrocenyl-5-phenyl[1,3,2]oxazaphospholidine 2-oxide 2 was carried out with diastereoselectivity of >99%, affording a new and efficient way for introducing planar chirality into the ferrocene backbone. Various electrophiles were used to quench the lithiated species, showing the wide applicability of the new ortho-directing group and its potential to generate ligands for use in asymmetric catalysis. 相似文献
72.
Richard C. Semelka Mateus de A. HernandesClifton G. Stallings Mauricio Castillo 《Magnetic resonance imaging》2013
Purpose
The purpose was to objectively evaluate a recently FDA-approved gadolinium-based contrast agent (GBCA) in comparison to our standard GBCA for acute adverse events and image quality by blinded evaluation.Methods
Evaluation was made of a recently FDA-approved GBCA, gadobutrol (Gadavist; Bayer), in comparison to our standard GBCA, gadobenate dimeglumine (MultiHance; Bracco), in an IRB- and HIPAA-compliant study. Both the imaging technologist and patient were not aware of the brand of the GBCA used. A total of 59 magnetic resonance studies were evaluated (59 patients, 31 men, 28 women, age range of 5–85 years, mean age of 52 years). Twenty-nine studies were performed with gadobutrol (22 abdominal and 7 brain studies), and 30 studies were performed with gadobenate dimeglumine (22 abdominal and 8 brain studies). Assessment was made of acute adverse events focusing on objective observations of vomiting, hives, and moderate and severe reactions. Adequacy of enhancement was rated as poor, fair and good by one of two experienced radiologists who were blinded to the type of agent evaluated.Results
No patient experienced acute adverse events with either agent. The target minor adverse events of vomiting or hives, and moderate and severe reactions were not observed in any patient. Adequacy of enhancement was rated as good for both agents in all patients.Conclusions
Objective, blinded evaluation is feasible and readily performable for the evaluation of GBCAs. This proof-of-concept study showed that both GBCAs evaluated exhibited consistent good image quality and no noteworthy adverse events. 相似文献73.
74.
Victor Martínez‐Agramunt Tobias Eder Heidar Darmandeh Gregorio Guisado‐Barrios Eduardo Peris 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(17):5738-5742
A palladium‐cornered molecular square with four pyrene‐bis(imidazolylidene) bridging ligands is reported. This metallo‐polygon can encapsulate C60 and C70. The X‐ray diffraction structures of the empty cage as well as the cages complexed with both fullerenes are described. The fullerene encapsulation produces perturbations in the structural parameters of the metallo‐square, showing that it can adjust the shape of its cavity to the size of each fullerene. 相似文献
75.
76.
Fabin Olazarn-Santibaez Gildardo Rivera Venancio Vanoye-Eligio Arturo Mora-Olivo Gabriel Aguirre-Guzmn Mnica Ramírez-Cabrera Eder Arredondo-Espinoza 《Molecules (Basel, Switzerland)》2021,26(2)
Equisetum myriochaetum is a semi-aquatic plant found on riverbanks that is commonly used in traditional medicine as a diuretic agent. Additionally, the genus Equisetum stands out for its content of the flavonoid kaempferol, a well-known antiproliferative agent. Therefore, in this study, E. myriochaetum ethanolic extract was tested in vitro against a cervical cancer cell line (SiHa). Additionally, the antioxidative activity was evaluated through a 2,2-diphenyl-1-picrilhidrazil (DPPH) assay. Finally, a molecular docking analysis of apigenin, kaempferol, and quercetin on the active site of β-tubulin was performed to investigate their potential mechanism of action. All fractions of E. myriochaetum ethanolic extract showed antioxidative activity. Fraction 14 displayed an antiproliferative capacity with a half maximal inhibitory concentration (IC50) value of 6.78 μg/mL against SiHa cells. 相似文献
77.
Valquiria P. Andrade Mateus Mittersteiner Márcio M. Lobo Clarissa P. Frizzo Hélio G. Bonacorso Marcos A.P. Martins Nilo Zanatta 《Tetrahedron letters》2018,59(10):891-894
This study reports a comparison between conventional methods, ionic liquids, microwave (MW) irradiation, and combinations thereof for the synthesis of a series of fourteen 1-aryl-2-arylamino-5-trifluoroacetyl-1,2,3,4-tetrahydropyridines. In all of the reactions tested, the products were obtained at very good yields (87–97%), but the reaction times were very different, depending on the method used. Comparing to other methods, the time decreased to 1?min when [BMIM]BF4 under MW irradiation was used, thus evidencing a synergic effect. 相似文献
78.
Vânia G. Zuin Mateus L. Segatto Luize Z. Ramin 《Current Opinion in Green and Sustainable Chemistry》2018
Over the last century, the conventional and linear production system has significantly influenced the socio-environment globally. The transition to a more circular production system, aiming at maintaining the value of products and resources for as long as possible, is an opportunity to create innovative processes that are regenerative by intention. This means replacing the end-of-life concept with restoration, renewable energy use and by- or co-products as well as eliminating toxic chemicals by developing and using redesigned materials, procedures and business models. In this context, the main objective of this paper is to present a critical overview related to the most recent green and sustainable extraction or separation approaches to remove organic molecules from plant-derived resources, specifically agro-industrial and forestry waste using circular processing systems in operation in the last four years. 相似文献
79.
Ohne Zusammenfassung 相似文献
80.