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181.
Maillard Christophe Maloubier Didier Boulay Olivier Savigny Victor Quemet Alexandre 《Journal of Radioanalytical and Nuclear Chemistry》2021,330(3):579-587
Journal of Radioanalytical and Nuclear Chemistry - Due to unexpected Pu behavior using the U/TEVA resin and the most-recognized reagents, some key separation stages need to be studied for the... 相似文献
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Alexander V. Astakhov Kyrill Yu. Suponitsky Victor M. Chernyshev 《Mendeleev Communications》2018,28(4):439-441
An efficient synthesis of 2-amino-1-R-[1,2,4]triazolo[1,5-a]- pyrimidinium or 3-amino-2-R-[1,2,4]triazolo[4,3-a]pyrimidi- nium chloride derivatives by heterocyclization of 3,5-diamino- 1-R-1,2,4-triazoles (R = Alk or Ar) with pentane-2,4-diones was developed. The process is promoted by chlorotrimethyl- silane which plays the dual role of carbonyl-activating agent and water scavenger. 相似文献
187.
This paper shows that a finitely presented monoid with linear Dehn function need not have a regular cross-section, strengthening the previously-known result that such a monoid need not be presented by a finite complete string rewriting system, and contrasting with the fact that finitely presented groups with linear Dehn function always have regular cross-sections. 相似文献
188.
Metal Oxide Assisted Preparation of Core–Shell Beads with Dense Metal–Organic Framework Coatings for the Enhanced Extraction of Organic Pollutants
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Mateo del Rio Dr. Carlos Palomino Cabello Veronica Gonzalez Dr. Fernando Maya Dr. Jose B. Parra Dr. Victor Cerdà Dr. Gemma Turnes Palomino 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(33):11770-11777
Dense and homogeneous metal–organic framework (MOF) coatings on functional bead surfaces are easily prepared by using intermediate sacrificial metal oxide coatings containing the metal precursor of the MOF. Polystyrene (PS) beads are coated with a ZnO layer to give ZnO@PS core–shell beads. The ZnO@PS beads are reactive in the presence of 2‐methylimidazole to transform part of the ZnO coating into a porous zeolitic imidazolate framework‐8 (ZIF‐8) external shell positioned above the internal ZnO precursor shell. The obtained ZIF‐8@ZnO@PS beads can be easily packed in column format for flow‐through applications, such as the solid‐phase extraction of trace priority‐listed environmental pollutants. The prepared material shows an excellent permeance to flow when packed as a column to give high enrichment factors, facile regeneration, and excellent reusability for the extraction of the pollutant bisphenol A. It also shows an outstanding performance for the simultaneous enrichment of mixtures of endocrine disrupting chemicals (bisphenol A, 4‐tert‐octylphenol and 4‐n‐nonylphenol), facilitating their analysis when present at very low levels (<1 μg L?1) in drinking waters. For the extraction of the pollutant bisphenol A, the prepared ZIF‐8@ZnO@PS beads also show a superior extraction and preconcentration capacity to that of the PS beads used as precursors and the composite materials obtained by the direct growth of ZIF‐8 on the surface of the PS beads in the absence of metal oxide intermediate coatings. 相似文献
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The addition of lithium benzylthiolates to Nα,-formyl-α,β-dehydro-α-amino acid esters gave protected Nα-formyl-β-S-benzyl-β,β-dialkylcysteine esters. Hydrolysis and Nα-protection produced β,β-dialkyl-cysteines which can be used for peptide synthesis. 相似文献
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Dr. Yoichi Hoshimoto Keita Ashida Yukari Sasaoka Dr. Ravindra Kumar Prof. Dr. Ken Kamikawa Prof. Dr. Xavier Verdaguer Prof. Dr. Antoni Riera Prof. Dr. Masato Ohashi Prof. Dr. Sensuke Ogoshi 《Angewandte Chemie (International ed. in English)》2017,56(28):8206-8210
The nickel(0)-catalyzed carbonylative cycloaddition of 1,5- and 1,6-ene-imines with carbon monoxide (CO) is reported. Key to this reaction is the efficient regeneration of the catalytically active nickel(0) species from nickel carbonyl complexes such as [Ni(CO)3L]. A variety of tri- and tetracyclic γ-lactams were thus prepared in excellent yields with 100 % atom efficiency. Preliminary results on asymmetric derivatives promise potential in the synthesis of enantioenriched polycyclic γ-lactams. 相似文献