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Journal of Flow Chemistry
Authors: Natan Straathof, Dannie Osch, Arian Schouten, Xiao Wang, Jaap Schouten, Volker Hessel, and Timothy Noël

A visible light photocatalytic metal-free perfluoroalkylation method for the functionalization of heteroarenes in continuous flow was developed. Eosin Y was the most efficient photocatalyst with regard to substrate scope, reaction time and cost prize. Faster reaction times were observed in continuous flow compared to batch due to an improved irradiation of the reaction mixture on a microscale. Several pyrroles and indoles were perfluoroalkylated within 30 min residence time (six examples). The trifluoromethylation of pyrroles and indoles was achieved by using a gas–liquid flow with CF3I as a cheap CF3 source (three examples).

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Journal of Flow Chemistry
Authors: Zine Eddine Hamami, Laurent Vanoye, Pascal Fongarland, Claude de Bellefon, and Alain Favre-Reguillon

An efficient and metal-free method for the oxidation of aldehydes to the corresponding carboxylic acids has been developed. In a simple continuous-flow photochemical reactor, the use of camphorquinone (CQ) irradiated with a white light-emitting diode (LED) source enhanced the autoxidation of aldehydes. Under 5 bar of oxygen, visible light, and 0.3 mol% of CQ, the rate of oxidation was increased from 6 times with 2-ethylhexanal to 30 times for n-nonanal. The large interfacial area generated by a segmented flow apparatus associated with radicals formed by photooxidation of CQ ensures metal-free high throughput of carboxylic acids under safe conditions.

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Abstract  

In our previous work we characterized the Ca binding properties of BLA by analysis of Ca-induced renaturation in the presence of urea. In this study we focused on the renaturing capacity of CaCl2 in the absence of urea and analysed the apparent thermodynamic and kinetic properties of renatured BLA by DSC, CD and dynamic light scattering (DLS) measurements. Ca-free protein did not return fully to the native state even after extensive dialysis against high concentrations of calcium. Thus Ca removal provokes changes in protein structure that can not be reversed completely even by addition of an excess of calcium. However, activity studies performed simultaneously with the DSC experiments showed a significant return of enzymatic activity despite the failure of complete return of native stability. This conclusion is in excellent agreement with findings of Machius et al. who suggested on the basis of their X-ray studies that it is not possible to remove CaI and CaII without introducing significant structural changes. It is important to note that all unfolding reactions of metal-free, partially renatured and native protein were found to be irreversible. Therefore the DSC transition curves were fitted using irreversible transition models. It turned out that the apparent heat capacity profiles of partially renatured BLA could be well represented by superposition of two irreversible processes each following the two-state irreversible model.

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Abstract  

The chemical effect of7Be recoils formed through a12C/, n/7Be process from ligand carbon atoms was investigated in a several phthalocyanines. It was found that7Be-phthalocyanine was synthesized by7Be recoil. Net radiochemical yields of7Be-phthalocyanine were estimated to be 10–20% for copper and zinc phthalocyanines, while for metal-free phthalocyanines, yields above 90% were obtained.

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Metal-free stereoselective additions of activated nucleophiles to β-nitrostyrenes were investigated under continuous-flow conditions in microreactors, in the presence of a chiral bifunctional catalyst. Optimization of the experimental setup gave excellent enantioselectivities (up to 85% e.e.) and higher productivities if compared to the flask syntheses. The potential of this flow chemistry approach was demonstrated by the successful synthesis of an advanced intermediate for the preparation of the GABAB receptor agonist Baclofen.

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Nanopages
Authors: S. Talapatra, T. Kim, B. Q. Wei, S. Kar, R. Vajtai, G. V. S. Sastry, M. Shima, D. Srivastava, and P. M. Ajayan

We report on the room temperature ferromagnetism observed in heat treated nanocrystalline diamonds. By systematic annealing of nanocrystalline diamond, graphitic nanoclusters having finite magnetization with well-defined hysteresis and coercivity, and a Curie temperature (TC) well above 400 K (estimated TC ~ 590 K), were synthesized. Using detailed analysis of the structural modification at various annealing stages, with Raman Spectroscopy and High Resolution Transmission Electron Microscopy, we show that the carbon bonding configuration has important consequence to the observed magnetism in these samples. These findings could lead to controlled fabrication of metal free magnetic carbon system.

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Journal of Flow Chemistry
Authors: Olav Bleie, Michael F. Roberto, Thomas I. Dearing, Charles W. Branham, Olav M. Kvalheim, and Brian J. Marquardt

The Moffatt-Swern oxidation (MSO) is a multistep, versatile, metal-free reaction by which alcohols are transformed into aldehydes and ketones. Batch MSO requires low temperatures (−70 °C) due to a highly exothermic reaction step that generates intermediates. This work shows that a rigorous investigation of the MSO in batch can be used as a stepping-stone to its implementation in a continuous-flow reactor (CFR). This work has two parts: the first part details the investigation of MSO in batch; the second covers the translation of the knowledge derived from batch to a CFR. The MSO batch reaction was performed under cryogenic conditions with real-time process monitoring. The reaction was monitored with Raman spectroscopy and could be tracked throughout the reaction. All concentrations were validated using offline high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Two configurations of the CFR were produced. Configuration 1 used the traditional batch methodology in terms of reagent addition and reaction conditions. Configuration 2 used the information derived from the batch reaction, changing the order of the reagent addition and increasing the temperature of the reactor. Real-time quantitative monitoring of chemical yield in the CFR was demonstrated via Raman spectroscopy and partial least squares (PLS) regression modeling. Reaction yield was accurately predicted every 15 s, reducing the need for chromatographic validation once the model was built. Configuration 2 was shown to perform comparably to configuration 1 at low temperature and far outperforming it at higher temperatures. Both CFR configurations performed significantly better than the batch setup in terms of temperature and yield, as was expected.

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of the Salix rhizosphere soil near a lead and zinc mine. Cereal Research Communications. 34. 311–314. Malcová, R., Rydlová, J. & Vosátka, M., 2003. Metal-free cultivation of Glomus sp. BEG140

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Resolution and Discovery
Authors: Martial Duchamp, Vadim Migunov, Amir H. Tavabi, Adnan Mehonic, Mark Buckwell, Manveer Munde, Anthony J. Kenyon, and Rafal E. Dunin-Borkowski

A , Buckwell M , Montesi L , Garnett L , Hudziak S , Fearn S , Chater R , McPhail D , Kenyon AJ : Structural changes and conductance thresholds in metal-free intrinsic SiOx resistive random access memory . J Appl Phys 117

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Further Flow Chemistry Publications “ Metal-free oxidative fluorination of phenols with [18 F]fluoride ” Z. Gao , Y. H. Lim , M. Tredwell , L. Li , S. Verhoog , M. Hopkinson , W. Kaluza , T. L. Collier , J

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