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361.
René R. E. Steendam Maxime C. T. Brouwer Evelien M. E. Huijs Michaël W. Kulka Dr. Hugo Meekes Dr. Willem J. P. van Enckevort Dr. Jan Raap Prof. Dr. Floris P. J. T. Rutjes Prof. Dr. Elias Vlieg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13527-13530
Here we demonstrate that deracemization of isoindolinones using Viedma ripening is possible starting from a racemic mixture of conglomerate crystals. Crystals of the enantiopure isoindolinones lose their chiral identity upon dissolution even without the need for a catalyst. This enabled complete deracemization of the reported isoindolinones without a catalyst. 相似文献
362.
Daniel Kamzol Maxime Neuville Chloé Cocaud Killian Tiger Baptiste Taffoureau Prof. Dr. Krzysztof Lewiński Justyna Jaszczyk Prof. Dr. Olivier R. Martin Dr. Sebastian Baś Prof. Dr. Sylvain Routier Prof. Dr. Isabelle Gillaizeau Dr. Frédéric Buron Dr. Cyril Nicolas 《European journal of organic chemistry》2023,26(39):e202300762
A comprehensive study of the preparation and reactivity of N-tert-butanesulfinyl glycosylamines with simple Grignard and organo lithium reagents in batch vs. continuous flow chemistry is reported. As they readily react as latent imine equivalents with a variety of carbon nucleophiles, these carbohydrate derivatives constitute very useful precursors for the diastereoselective synthesis of bioactive compounds such as iminosugar-C-glycosides. A hybrid protocol, involving the addition of benzylmagnesium chloride to a (SR)-arabinofuranosylamine substrate in flow, at room temperature, combined with a cyclization protocol in batch is also described for the first time. Of note, this semi-continuous flow process shortens the synthesis of imino-C-glycoside scaffolds to a single workday. 相似文献
363.
Marta Delgado Gómez Dr. Marco Marazzi Prof. José Elguero Maxime Ferrer Prof. Ibon Alkorta 《Chemphyschem》2023,24(17):e202300214
Theoretical chemistry (DLPNO-CCSD(T)/def2-TZVP//M06-2x/aug-cc-pVDZ) was used to design a system based on ammonia boranes catalyzed by pyrazoles with the aim of producing dihydrogen, nowadays of high interest as clean fuel. The reactivity of ammonia borane and cyclotriborazane were investigated, including catalytic activation through 1H-pyrazole, 4-methoxy-1H-pyrazole, and 4-nitro-1H-pyrazole. The results point toward a catalytic cycle by which, at the same time, ammonia borane can initially store and then, through catalysis, produce dihydrogen and amino borane. Subsequently, amino borane can trimerize to form cyclotriborazane that, in presence of the same catalyst, can also produce dihydrogen. This study proposes therefore a consistent progress in using environmentally sustainable (metal free) catalysts to efficiently extract dihydrogen from small B−N bonded molecules. 相似文献
364.
Clément M Ménard H Rowntree PA 《Langmuir : the ACS journal of surfaces and colloids》2008,24(15):8045-8049
A new sensitive and specific method to measure gold and palladium surface areas using alkanethiol adsorption coupled with analysis by gas chromatography with mass spectrometry detection has been developed. The effectiveness of the method was tested with metallic samples having a known surface area. The results have also been compared with BET specific surface area measurements. The results obtained with both methods show a good correlation. 相似文献
365.
Bonnet S Siegler MA Costa JS Molnár G Bousseksou A Spek AL Gamez P Reedijk J 《Chemical communications (Cambridge, England)》2008,(43):5619-5621
The two-step spin crossover of a new mononuclear iron(ii) complex is studied by magnetic, crystallographic and calorimetric methods revealing two successive first-order phase transitions and an ordered intermediate phase built by the repetition of the unprecedented [HS-LS-LS] motif. 相似文献
366.
Steinhaus graphs on vertices are certain simple graphs in bijective correspondence with binary -sequences of length . A conjecture of Dymacek in 1979 states that the only nontrivial regular Steinhaus graphs are those corresponding to the periodic binary sequences of any length . By an exhaustive search the conjecture was known to hold up to 25 vertices. We report here that it remains true up to 117 vertices. This is achieved by considering the weaker notion of parity-regular Steinhaus graphs, where all vertex degrees have the same parity. We show that these graphs can be parametrized by an -vector space of dimension approximately and thus constitute an efficiently describable domain where true regular Steinhaus graphs can be searched by computer.
367.
Levine DR Caruso A Siegler MA Tovar JD 《Chemical communications (Cambridge, England)》2012,48(50):6256-6258
The synthesis of new boron-containing acenes (meta-B-entacenes) is reported. These compounds exhibit slightly non-planar core geometries with blue-shifted spectral properties and more negative electrochemical reduction potentials relative to known para isomers. Polarizable π-extended architectures were realized via cross-coupling procedures with chloro-functionalized precursors. 相似文献
368.
Sanguinet L Pozzo JL Guillaume M Champagne B Castet F Ducasse L Maury E Soulié J Mançois F Adamietz F Rodriguez V 《The journal of physical chemistry. B》2006,110(22):10672-10682
This paper presents a series of acidoswitchable NLO-phores combining the 9-methylbenzimidazolo[2,3-b]oxazolidine core with various pi systems such as phenylethenyl, phenylethynyl, and naphthylethenyl. All the prepared derivatives are shown to display acidochromic behavior at ambient temperature. The remarkable contrast in the NLO response along the reversible transformations observed in HRS experiments is rationalized by high level theoretical calculations. 相似文献
369.
Maxime Robin Stephane Mialhe Valerie Pique Robert Faure Jean‐Pierre Galy 《ChemInform》2002,33(38):153-153
370.