An electrochemical method for the green and practical synthesis of a broad range of substituted isoxazoline cores is presented. Both aryl and more challenging alkyl aldoximes are converted to the desired isoxazoline in an electrochemically enabled regio- and diastereoselective reaction with electron-deficient alkenes. Additionally, in-situ reaction monitoring methods compatible with electrochemistry equipment have been developed in order to probe the reaction pathway. Supporting analyses from kinetic (time-course) modelling and density functional theory support a stepwise, radical-mediated mechanism, and discounts hypothesised involvement of closed shell [3+2] cycloaddition pathways. 相似文献
The challenge of defining a length on the nanoscale is non‐trivial. For a well‐defined inorganic nanoscale species, a size measurement can describe a number of different dimensions (core, shell, solvation sphere). Often size is reported out of context or even inadvertently misrepresented. Since many of the techniques used to measure size depend on significant and sometimes destructive sample preparation, an additional challenge is defining “what size means” for a nanoscale species in solution. In this Concept, the distinction is made between complementary techniques that can be used together to unveil more information about the material in question, and corroborative techniques, which are used to make multiple measurements of the same property. Additionally, corroborative techniques can be used to measure the same property in and out‐of solution so as to reveal details about solution behaviour. We highlight various approaches to this characterization challenge in the context of three case studies that demonstrate the use of both complementary and corroborative techniques to elucidate the various functional dimensions of different types of inorganic nanoscale species in solution. 相似文献
Finding the few : Cell‐surface proteins are useful disease biomarkers, but current high‐throughput methods are limited to detecting cells expressing more than several hundred proteins. Enzymatic amplification in microfluidic droplets (see picture) is a high‐throughput method for detection and analysis of cell‐surface biomarkers expressed at very low levels on individual human cells. Droplet optical labels allow concurrent analysis of several samples.
Sensors and sensitivity : A highly luminescent microporous metal–organic framework, [Zn2(bpdc)2(bpee)] (bpdc=4,4′‐biphenyldicarboxylate; bpee=1,2‐bipyridylethene), is capable of very fast and reversible detection of the vapors of the nitroaromatic explosive 2,4‐dinitrotoluene and the plastic explosive taggant 2,3‐dimethyl‐2,3‐dinitrobutane, through redox fluorescence quenching with unprecedented sensitivity (see spectra).
