Practical Application of the Aqueous ‘Sulfonyl-Azide-Free’ (SAFE) Diazo Transfer Protocol to Less α-C–H Acidic Ketones and Esters

Synthesis ◽  
2019 ◽  
Vol 51 (22) ◽  
pp. 4284-4290 ◽  
Author(s):  
Dmitry Dar’in ◽  
Grigory Kantin ◽  
Mikhail Krasavin

The earlier described ‘sulfonyl-azide-free’ (‘SAFE’) protocol for diazo transfer to CH-acidic 1,3-dicarbonyl compounds (and their similarly activated congeners) has been extended to the less reactive monocarbonyl substrates, which previously required a separate activation step. Formylation in situ, followed by the addition of an optimized amount of the ‘SAFE cocktail’ (obtained by mixing sodium azide, potassium carbonate, and m-carboxybenzenesulfonyl chloride in water) led to the formation of the desired diazo compounds, which were isolated by extraction in moderate to excellent yields, and, in most cases, with no need for additional purification.

2016 ◽  
Vol 14 (45) ◽  
pp. 10723-10732 ◽  
Author(s):  
Jijun Chen ◽  
Ying Shao ◽  
Liang Ma ◽  
Meihua Ma ◽  
Xiaobing Wan

A novel in situ generation of nitrilium from nitrile ylide and the subsequent Mumm rearrangement of carboxylic acid, nitrile, and diazo compounds gave various unsymmetrical diacylglycine esters.


Author(s):  
Li-Min Wang ◽  
Xiaokuan Ban ◽  
Zongzi Jin ◽  
Ranran Peng ◽  
Chusheng Chen ◽  
...  

Severe dendrite growth, low Coulombic efficiency and huge volume change have impeded the practical application of Li metal anode, and the construction of porous scaffolds is an effective strategy to...


2020 ◽  
Vol 8 (45) ◽  
pp. 16151-16159
Author(s):  
Shaoxiong Wang ◽  
Jidong Lin ◽  
Xiaoyan Li ◽  
Jiangkun Chen ◽  
Changbin Yang ◽  
...  

Yb/Er:NaLuF4@glass with in situ reversible cubic-to-hexagonal phase transition on cyclic heat-treatment shows practical application in high-level anticounterfeiting.


1993 ◽  
Vol 18 ◽  
pp. 60-64 ◽  
Author(s):  
Takuo Kitahara ◽  
Masataka Shirakashi ◽  
Yasuhiro Kajio

Hydraulic conveying of snow is one of the most promising techniques for snow removal from an urban area. The method for measuring the fraction of snow in a snow-water mixture flowing in a pipe is a key technique for its practical application. A new method based on the conductometric method has been developed in this study. The method was tested using a prototype snow-fraction meter in a testing apparatus and a closed pipeline system. This type of meter has the advantage of in situ measurement of a wide fraction range from zero up to packed value. The meter is capable of quick response, independent of flow velocity or snow properties and nonintrustive in flow. This paper describes the application of techniques for the development of the meter and the test results. This new method is expected to be useful for hydraulic conveying of ice particles or ice cubes, a new technology in the air-conditioning field.


2001 ◽  
Vol 676 ◽  
Author(s):  
Jianjun Wang ◽  
Luke Grocholl ◽  
Edward G. Gillan

ABSTRACTWe report a straightforward, non-aqueous solvothermal method for the production of nanoscale gallium nitride structures. Nanoparticles with spherical and rod-like morphologies are produced via in situ gallium azide precursor synthesis and decomposition in superheated toluene or THF. The solution reaction between gallium chloride and sodium azide produces an insoluble azide precursor that is then solvothermally decomposed to GaN at temperatures below 260 °C. The resulting products are poorly crystalline but thermally stable and crystallize to hexagonal GaN upon annealing at 750 °C. Product morphologies include spherical particles (ca. 50 nm) and nanorods. Upon annealing, the nanoparticles coalesce into larger organized crystalline structures with hexagonal facets.


2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Yu Luo ◽  
Bo Bai ◽  
Honglun Wang ◽  
Yourui Suo ◽  
Yiliang Yao

Alginate has been extensively used as absorbents due to its excellent properties. However, the practical application of pure alginate has been restricted since the saturated adsorbent has weak physical structure and could not be regenerated easily. In this study, a low-cost and renewable composite MnO2@alginate/Mn adsorbent has been prepared facilely for the absorptive removal of antibiotic wastewater. FE-SEM, FTIR, and XRD analyses were used to characterize the samples. The norfloxacin (NOR) was used as an index of antibiotics. More specifically, the batch absorption efficiency of the adsorbents was evaluated by pH, contact time with different NOR concentration, and the temperature. Thus, the performance of absorption kinetic dynamics and isotherm equations were estimated for the adsorptive removal process. Parameters includingΔG0,ΔH0, andΔS0were utilized to describe the feasible adsorption process. To regenerate the saturated absorptive sites of the adsorbent, the heterogeneous Fenton-like reactions were trigged by introduction of H2O2. The results showed that the in situ regenerating has exhibited an excellent recycling stability. The high activity and the simple fabrication of the adsorbents make them attractive for the treatment of wastewater containing refractory organic compound and also provide fundamental basis and technology for further practical application.


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