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51.
Dr. Luke D. Elliott Dr. Jonathan P. Knowles Dr. Paul J. Koovits Katie G. Maskill Michael J. Ralph Dr. Guillaume Lejeune Lee J. Edwards Richard I. Robinson Ian R. Clemens Brian Cox David D. Pascoe Guido Koch Martin Eberle Malcolm B. Berry Prof. Kevin I. Booker‐Milburn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(46):15226-15232
The use of flow photochemistry and its apparent superiority over batch has been reported by a number of groups in recent years. To rigorously determine whether flow does indeed have an advantage over batch, a broad range of synthetic photochemical transformations were optimized in both reactor modes and their yields and productivities compared. Surprisingly, yields were essentially identical in all comparative cases. Even more revealing was the observation that the productivity of flow reactors varied very little to that of their batch counterparts when the key reaction parameters were matched. Those with a single layer of fluorinated ethylene propylene (FEP) had an average productivity 20 % lower than that of batch, whereas three‐layer reactors were 20 % more productive. Finally, the utility of flow chemistry was demonstrated in the scale‐up of the ring‐opening reaction of a potentially explosive [1.1.1] propellane with butane‐2,3‐dione. 相似文献
52.
Dr. Elena Riva Dr. Ina Wilkening Silvia Gazzola W. M. Ariel Li Dr. Luke Smith Prof. Peter F. Leadlay Dr. Manuela Tosin 《Angewandte Chemie (International ed. in English)》2014,53(44):11944-11949
A library of functionalized chemical probes capable of reacting with ketosynthase‐bound biosynthetic intermediates was prepared and utilized to explore in vivo polyketide diversification. Fermentation of ACP mutants of S. lasaliensis in the presence of the probes generated a range of unnatural polyketide derivatives, including novel putative lasalocid A derivatives characterized by variable aryl ketone moieties and linear polyketide chains (bearing alkyne/azide handles and fluorine) flanking the polyether scaffold. By providing direct information on microorganism tolerance and enzyme processing of unnatural malonyl‐ACP analogues, as well as on the amenability of unnatural polyketides to further structural modifications, the chemical probes constitute invaluable tools for the development of novel mutasynthesis and synthetic biology. 相似文献
53.
This work reports the ambient temperature synthesis and structural characterization of six new first row transition metal acetylenedicarboxylate coordination polymers. The Co and two Ni compounds adopt structures in which the octahedral metals are connected into 1D chains via the acetylenedicarboxylate ligand. In contrast the Mn and two Zn compounds adopt 3D metal-organic frameworks; while the Mn compound is non-porous the two Zn structures contain dimeric or trimeric clusters connected into frameworks that are potentially porous. These two anionic metal-organic frameworks are, however, charged balanced by cations siting in their pores which greatly reduces the ability to access their porosity. 相似文献
54.
Dr. Zhen Jiang Ming Li Tan Mahdiar Taheri Dr. Qiao Yan Prof. Takuya Tsuzuki Dr. Michael G. Gardiner Broden Diggle Prof. Luke A. Connal 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7115-7122
The most pressing challenges for light-driven hydrogel actuators include reliance on UV light, slow response, poor mechanical properties, and limited functionalities. Now, a supramolecular design strategy is used to address these issues. Key is the use of a benzylimine-functionalized anthracene group, which red-shifts the absorption into the visible region and also stabilizes the supramolecular network through π–π interactions. Acid–ether hydrogen bonds are incorporated for energy dissipation under mechanical deformation and maintaining hydrophilicity of the network. This double-crosslinked supramolecular hydrogel developed via a simple synthesis exhibits a unique combination of high strength, rapid self-healing, and fast visible-light-driven shape morphing both in the wet and dry state. As all of the interactions are dynamic, the design enables the structures to be recycled and reprogrammed into different 3D objects. 相似文献
55.
Luke Green Keith Livingstone Dr. Sophie Bertrand Dr. Simon Peace Dr. Craig Jamieson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(65):14866-14870
A range of 1,3,4-oxadiazoles have been synthesized using a UV-B activated flow approach starting from carboxylic acids and 5-substituted tetrazoles. The application of UV light represents an attractive alternative to the traditional thermolytic approach and has demonstrated comparable efficiency and versatility, with a diverse substrate scope, including the incorporation of highly substituted amino acids. 相似文献
56.
Samuel W. Foster Xiaofeng Xie Michelle Pham Paul A. Peaden Leena M. Patil Luke T. Tolley Paul B. Farnsworth H. Dennis Tolley Milton L. Lee James P. Grinias 《Journal of separation science》2020,43(9-10):1623-1627
A newly developed portable capillary liquid chromatograph was investigated for the separation of various pharmaceutical and illicit drug compounds. The system consists of two high‐pressure syringe pumps capable of delivering capillary‐scale flow rates at pressures up to 10 000 psi. Capillary liquid chromatography columns packed with sub‐2 μm particles are housed in cartridges that can be inserted into the system and easily connected through high‐pressure fluidic contact points by simply applying a specific, predetermined torque rather than using standard fittings and less precise sealing protocols. Several over‐the‐counter analgesic drug separations are demonstrated, along with a simple online measurement of tablet dissolution. Twenty illicit drug compounds were also separated across six targeted drug panels. The results described in this study demonstrate the capability of this compact liquid chromatography instrument to address several important drug‐related applications while simplifying system operation, and greatly reducing solvent usage and waste generation essential for onsite analysis. 相似文献
57.
Welch Nathan J. Carey J. William Frash Luke P. Hyman Jeffrey D. Hicks Wes Meng Meng Li Wenfeng Menefee Anne H. 《Transport in Porous Media》2022,141(1):17-47
Transport in Porous Media - Fluid flow in fractures has the potential to drastically change the economic, environmental, and safety risks associated with a subsurface operation. This work focuses... 相似文献
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Ronald R. Martin Steven J. Naftel Stéphanie M. Doucet Daniel Hanley Christopher G. Weisner 《X射线光谱测定》2013,42(6):437-441
Synchrotron radiation analysis is a powerful tool for identifying pollutants. Here, we explore the distribution of elements in the flight feathers of ring‐billed gulls, Larus delawarensis, to identify potential pollutants and their distribution throughout the feather. Our analysis using Synchrotron Radiation Analysis and Environmental Scanning Electron Microscopy has identified a variety of metals that are integral parts of the feather structure including: calcium (Ca), strontium (Sr), zinc (Zn) and iron (Fe). The darker portions of the flight feather were enriched with Zn and Fe, which supports the suggestion that feather melanins are efficient ligands of some metals found in the environment, sequestering potentially harmful particles away from the body. However, trace lead (Pb) acquired from the regional pollution was detected only in females, and it was distributed across both the melanized and non‐melanized portions of the feather suggesting that only some metals are efficiently sequestered by melanins. Overall this study highlights a potential method for identifying pollutants using bird feathers, which has broader implications on environmental sensing as well as avian and human health. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献