Nitrogen selenium

In spite of the hazardous nature of Sc4N4, this binary selenium nitride has been used for the synthesis of other Se-N compounds, all of which have sulfur analogues (Scheme 5.2). " However, safer alternatives to the use of Sc4N4, e.g., selenium-nitrogen halides and silicon-nitrogen-selenium reagents, are available for the development of Se-N chemistry. ... 

Selenium (and sulfur) dichlorides are useful reagents for the synthesis of organoselenium compounds,18 nitrogen selenium heterocycles19-21 and other selenium compounds. The key steps in these reactions usually involve a... 

Selenium and Nitrogen Selenium Nitride—Nitrosylselonie Arid. 

In this chapter, we will review the use of ylides as enantioselective organocata-lysts. Three main types of asymmetric reaction have been achieved using ylides as catalysts, namely epoxidation, aziridination, and cyclopropanation. Each of these will be dealt with in turn. The use of an ylide to achieve these transformations involves the construction of a C-C bond, a three-membered ring, and two new adjacent stereocenters with control of absolute and relative stereochemistry in one step. These are potentially very efficient transformations in the synthetic chemist s arsenal, but they are also challenging ones to control, as we shall see. Sulfur ylides dominate in these types of transformations because they show the best combination of ylide stability [1] with leaving group ability [2] of the onium ion in the intermediate betaine. In addition, the use of nitrogen, selenium and tellurium ylides as catalysts will also be described. 

Two boron-nitrogen-selenium heterocycles of types 248 and 249 were obtained when the triselenodiboronolanes (247) were treated with 1,2-dimethylhydrazine and aniline, respectively. The triselenadiborolanes required were obtained from the reaction of RBI2 and selenium. 

Salts of the sulfur-nitrogen-selenium cation radicals [SnSe3 N2]+ n = 1,2) have dimeric structures similar to that ofSeN42+ (7).i 436... 

Oxidized nitrogen. Selenium and selenides are dissolved as H2Se03 not, like Sg, to oxidation state (Vt), by hot, dilute or concentrated HNO3. 

Unsaturated natural fatty acids occur normally in the cis configuration ( oleic acid, - erucic acid, - linoleic acid, - linolenic acid). The conversion of oleic into elaidic acid is accomplished by treatment with SO2, oxides of nitrogen, selenium and acid-ac-... 

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