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Nikolaus Nestle Zi Jian Lim Tobias Böhringer Sarah Abtmeyer Sven Arenz Felix C. Leinweber Thomas Weiß Erik von Harbou 《Magnetic resonance in chemistry : MRC》2020,58(12):1213-1221
The considerations for use of compact nuclear magnetic resonance in a large-scale industrial environment clearly differ from those in academic and educational settings and even from those in smaller companies. In the first part of this article, these differences will be discussed along with the additional requirements that need to be fulfilled for successful applicability in different use cases. In the second part of the article, outcomes from different research activities aiming to fulfill these requirements will be presented with a focus on an online reaction-monitoring study on a lab-scale nucleophilic chlorination reaction. 相似文献
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Dr. İlhan Sevim Dr. Wolf Matthias Pankau Prof. Dr. Günter von Kiedrowski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(41):9032-9035
We re-evaluate our claim of a high diastereoselectivity in the self-relicating Diels–Alder reaction between maleimide 1 and fulvene 3 . It was shown that the system has a diastereoselectivity of 1.8:1 for NN-4 : NX-4 , which is contrary to the 16:1 ratio claimed by Dieckmann et al. The analysis of 1H NMR monitoring of the reaction revealed that both replicators show sigmoidal growth which is typical for auto-catalytic systems. 相似文献
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Dr. Boris Schade Dr. Abhishek Kumar Singh Dr. Virginia Wycisk Dr. Jose Luis Cuellar-Camacho Dr. Hans von Berlepsch Prof. Rainer Haag Dr. Christoph Böttcher 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(30):6919-6934
The syntheses of novel amphiphilic 5,5′,6,6′-tetrachlorobenzimidacarbocyanine (TBC) dye derivatives with aminopropanediol head groups, which only differ in stereochemistry (chiral enantiomers, meso form and conformer), are reported. For the achiral meso form, a new synthetic route towards asymmetric cyanine dyes was established. All compounds form J aggregates in water, the optical properties of which were characterised by means of spectroscopic methods. The supramolecular structure of the aggregates is investigated by means of cryo-transmission electron microscopy, cryo-electron tomography and AFM, revealing extended sheet-like aggregates for chiral enantiomers and nanotubes for the mesomer, respectively, whereas the conformer forms predominately needle-like crystals. The experiments demonstrate that the aggregation behaviour of compounds can be controlled solely by head group stereochemistry, which in the case of enantiomers enables the formation of extended hydrogen-bond chains by the hydroxyl functionalities. In case of the achiral meso form, however, such chains turned out to be sterically excluded. 相似文献
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Niklas Jänsch Wisely Oki Sugiarto Marius Muth Aleksandra Kopranovic Charlotte Desczyk Matthias Ballweg Frank Kirschhöfer Dr. Gerald Brenner-Weiss Prof. Dr. Franz-Josef Meyer-Almes 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(58):13249-13255
Human histone deacetylase 8 is a well-recognized target for T-cell lymphoma and particularly childhood neuroblastoma. PD-404,182 was shown to be a selective covalent inhibitor of HDAC8 that forms mixed disulfides with several cysteine residues and is also able to transform thiol groups to thiocyanates. Moreover, HDAC8 was shown to be regulated by a redox switch based on the reversible formation of a disulfide bond between cysteines Cys102 and Cys153. This study on the distinct effects of PD-404,182 on HDAC8 reveals that this compound induces the dose-dependent formation of intramolecular disulfide bridges. Therefore, the inhibition mechanism of HDAC8 by PD-404,182 involves both, covalent modification of thiols as well as ligand mediated disulfide formation. Moreover, this study provides a deep molecular insight into the regulation mechanism of HDAC8 involving several cysteines with graduated capability to form reversible disulfide bridges. 相似文献
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Juan A. Allegretto Agustín Iborra Dr. Juan M. Giussi Dr. Catalina von Bilderling Dr. Marcelo Ceolín Dr. Sergio Moya Dr. Omar Azzaroni Dr. Matias Rafti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(54):12388-12396
This work reports on a novel and versatile approach to control the structure of metal–organic framework (MOFs) films by using polymeric brushes as 3D primers, suitable for triggering heterogeneous MOF nucleation. As a proof-of-concept, this work explores the use of poly(1-vinylimidazole) brushes primer obtained via surface-initiated atom transfer radical polymerization (SI-ATRP) for the synthesis of Zn-based ZIF-8 MOF films. By modifying the grafting density of the brushes, smooth porous films were obtained featuring inherently hydrophobic microporosity arising from ZIF-8 structure, and an additional constructional interparticle mesoporosity, which can be employed for differential adsorption of targeted adsorbates. It was found that the grafting density modulates the constructional porosity of the films obtained; higher grafting densities result in more compact structures, while lower grafting density generates increasingly inhomogeneous films with a higher proportion of interparticle constructional porosity. 相似文献
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Amit Kumar Trevor Janes Subrata Chakraborty Prosenjit Daw Niklas vonWolff Raanan Carmieli Yael Diskin‐Posner David Milstein 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(11):3411-3415
We report a C?C bond‐forming reaction between benzyl alcohols and alkynes in the presence of a catalytic amount of KOtBu to form α‐alkylated ketones in which the C=O group is located on the side derived from the alcohol. The reaction proceeds under thermal conditions (125 °C) and produces no waste, making the reaction highly atom efficient, environmentally benign, and sustainable. Based on our mechanistic investigations, we propose that the reaction proceeds through radical pathways. 相似文献