Academic literature on the topic 'Mild oxidizing agent'

Modified polyacrylamide supported chlorochromate was synthesized and used as a versatile and efficient oxidizing agent for the oxidation of various organic compounds such as hydroxyl compounds, silylethers, oximes, thiols, and other compounds. Over oxidation of the products (aldehydes to carboxylic acids) was not observed with this oxidizing agent. The oxidant was insoluble in oxidation media and chromium (VI) ions remained firmly bound to the insoluble polymeric support after the oxidation reaction. The mild reaction condition, easy work-up, short reaction times, regenerability of the reagent and its easy preparation and handling are among the advantages of this new polymeric chlorochromate reagent.

In this paper 18 aryl substituted semicarbazides undergo rapid oxidation to the corresponding aryl azo compounds using NaNO2-acetic anhydride as a novel oxidizing agent under mild conditions for the first time.

A mild and efficient method for theipso-hydroxylation of arylboronic acids to the corresponding phenols was developed using (NH4)2S2O8as an oxidizing agent. The reactions were performed under metal-, ligand-, and base-free conditions.

The reaction of selenium dioxide, a mild oxidizing agent, leads to the initiation of polymerization of pyrrole. The presence of cadmium metal can generate CdSe/PPy nanocomposites however, without it, Se/ PPy composites have been isolated.

Banana lignin was subjected to oxidation, converting alpha hydroxyl to carbonyl. In this process, atmospheric oxygen acted as an oxidizing agent, CO₃O₄ as a catalyst under mild conditions of temperature and pressure.

Substituted benzimidazoles were obtained from o-phenylenediamine and organic halides in solvent-free medium. The procedure involves pyridine N-oxide as mild oxidizing agent. The benzimidazoles were prepared without the separation of the intermediates. The absence of catalysts and good yields are important benefits of the method.

A facile method for the direct conversion of oximes into carbonyl compounds by treatment with manganese triacetate is described. Manganese triacetate can be used for an effective and mild oxidizing agent for the regeneration of carbonyl compounds in good yield. Many functional groups are tolerated under reaction conditions.

Dasheng Leow of the National Tsing Hua University used (Eur. J. Org. Chem. 2014, 7347) photolysis to activate the air oxidation of hydrazine to generate diimide, that then reduced 1 selectively to 2. Kevin M. Peese of Bristol-Myers Squibb effected (Org. Lett. 2014, 16, 4444) ring-closing metathesis of 3 followed by in situ reduction to form 4. Jitendra K. Bera of the Indian Institute of Technology Kanpur effected (J. Am. Chem. Soc. 2014, 136, 13987) gentle oxidative cleavage of cyclooctene 5 to the dialde­hyde 6. Arumugam Sudalai of the National Chemical Laboratory observed (Org. Lett. 2014, 16, 5674) high regioselectivity in the oxidation of the alkene 7 to the ketone 8. Hao Xu of Georgia State University also observed (J. Am. Chem. Soc. 2014, 136, 13186) high regioselectivity in the oxidation of the alkene 9 with 10, leading to the urethane 11. Justin Du Bois of Stanford University developed (J. Am. Chem. Soc. 2014, 136, 13506) mild conditions for the net double amination of the alkene 12 with 13, leading to 14. Jiaxi Xu and Pingfan Li of the Beijing University of Chemical Technology devised (Org. Lett. 2014, 16, 6036) a protocol for the allylic thiomethylation of an alkene with 16, converting 15 to 17. Matthias Beller of the Leibniz-Institüt für Katalyse combined (Chem. Eur. J. 2014, 20, 15692) hydroformylation, aldol condensation, and reduction to convert the alkene 18 to the ketone 19. Phil S. Baran of Scripps/La Jolla added (Angew. Chem. Int. Ed. 2014, 53, 14382) the diazo dienone 21 to the alkene 20 to give, after exposure to HCl, the arylated product 22. Markus R. Heinrich of the Friedrich-Alexander-Universität Erlangen-Nürnberg employed (Chem. Eur. J. 2014, 20, 15344) Selectfluor as both an oxidizing and a fluorinating agent in the related addition of 24 to 23 to give 25. Debabrata Maiti at the Indian Institute of Technology Bombay activated (J. Am. Chem. Soc. 2014, 136, 13602) the ortho position of 27, then added that interme­diate to 26 to give 28.

This chapter presents a review on limited studies that have been conducted using advanced oxidation processes (AOPs) in treating biologically treated palm oil mill effluent. Palm oil mill effluent is the byproducts of palm oil production that is normally treated using a series of biological processes. However, despite being treated for a long period of retention time, the effluent still possesses high concentration of organics, nutrients, and highly colored, and will pollute the environment if not treated further. Advanced oxidation processes that utilized hydroxyl radicals as their oxidizing agents have the potential of further treating the biologically treated POME. Fenton oxidation, photocatalysis, and cavitation are the main AOPs that have been studied in polishing the biologically treated POME. Depending on the experimental conditions, the removal of organics, in terms of COD, TOC, and color, could reach up to more than 90%. Nevertheless, each of this process has its own limitations and further studies are needed to overcome these limitations.

In the last few years, there has been a significant increase in the demand for Uranium as historical inventories have been consumed and new reactor orders are being placed. Numerous mineralized properties around the world are being evaluated for Uranium recovery and new mining / milling projects are being evaluated and developed. Ore bodies which are considered uneconomical to mine by conventional methods such as tunneling or open pits, can be candidates for non-conventional recovery techniques, involving considerably less capital expenditure. Technologies such as Uranium In Situ Leaching / In Situ Recovery (ISL / ISR - also refered to as “solution mining”), have enabled commercial scale mining and milling of relatively small ore pockets of lower grade, and are expected to make a significant contribution to overall world wide uranium supplies over the next ten years. Commercial size solution mining production facilities have operated in the US since the mid 1970’s. However, current designs are expected to result in less radiological wastes and emissions relative to these “first” generation plants (which were designed, constructed and operated through the 1980s). These early designs typically used alkaline leach chemistries in situ including use of ammonium carbonate which resulted in groundwater restoration challenges, open to air recovery vessels and high temperature calcining systems for final product drying vs the “zero emmisions” vaccum dryers as typically used today. Improved containment, automation and instrumentation control and use of vacuum dryers in the design of current generation plants are expected to reduce production of secondary waste byproduct material, reduce Radon emisions and reduce potential for employee exposure to uranium concentrate aerosols at the back end of the milling process. In Situ Recovery in the U.S. typically involves the circulation of groundwater, fortified with oxidizing (gaseous oxygen e.g) and complexing agents (carbon dioxide, e.g) into an ore body, solubilizing the uranium in situ, and then pumping the solutions to the surface where they are fed to a processing plant (mill). Processing involves ion exchange and may also include precipitation, drying or calcining and packaging operations depending on facility specifics. This paper presents an overview of the ISR process and the health physics monitoring programs developed at a number of commercial scale ISL / ISR Uranium recovery and production facillities as a result of the radiological character of these processes. Although many radiological aspects of the process are similar to that of conventional mills, conventional-type tailings as such are not generated. However, liquid and solid byproduct materials may be generated and impounded. The quantity and radiological character of these by products are related to facility specifics. Some special monitoring considerations are presented which are required due to the manner in which radon gas is evolved in the process and the unique aspects of controlling solution flow patterns underground. The radiological character of these procesess are described using empirical data collected from many operating facilities. Additionally, the major aspects of the health physics and radiation protection programs that were developed at these first generation facilities are discussed and contrasted to circumstances of the current generation and state of the art of uranium ISR technologies and facilities.