Procedures for the carbodiazenylation of nonactivated olefins with a wide range of aryldiazonium salts have been developed. The azo compounds obtained can serve as valuable precursors for β-arylamines (carboamination products), β-amino acids, ketones, and various heterocyclic structures.

Oxidative and reductive carbodiazenylation of nonactivated olefins.

Neuere Methoden der präparativen organischen Chemie. 11. Oxydationen mit Selendioxyd

Selenium dioxide has developed considerable stature since it was first reviewed in this series. Search for examples of oxidation by selenium dioxide or selenious acid is difficult because the terms are seldom indexed. Frequently it is difficult to decide whether selenium dioxide or selenious acid was the oxidizing agent employed in a reaction because it is impossible to determine if water was present. The determination is complex because the free acid or anhydride may react reversibly or irreversibly with various solvents such as alcohols or acids. To give selenium-containing compounds of unknown structure which might be the real oxidizing gents. In this chapter, the practical aspects of oxidation with selenium dioxide are summarized. Mechanisms are treated in detail.


Keywords:

selenium dioxide;
oxidation;
organoselenium compounds;
allylic oxidations;
aliphatic carbonyl compounds;
experimental considerations

Selenium Dioxide Oxidation

Analytical uses of phenylhydrazines and phenylhydrazones. I

Oxygenated and reduced selenium and tellurium compounds, particularly thoese of practical importance have been extensively investigated especially during the last few decades. Selenium(IV) oxide, selenoxides, selenones, seleninic and peroxyseleninic acids, selenenamides and seleninamides are involved in oxyfunctionalization of unsaturated hydrocarbons, their derivatives, alkylarenes, sulfides and amines, carbon-oxygen and carbon-carbon bond cleavage, ring closure and ring transformations, syn-elimination, sigmatropic [2,3]-rearrangement and other, chemo- regio- and stereocontrolled reactions. The chemistry of oxygenated tellurium compounds has been less extensively explored than their selenium counterparts;, nevertheless some of them have been successfully used for oxyfunctionalization of different groups of organic compounds while telluroxide elimination has gained more attention in the last years becoming a well-established method for the synthesis of olefins. Hydrogen selenide and telluride, alkali selenides and tellurides, selenoles and telluroles are the most common reduced derivative of these elements. Their properties are expressed in many reactions such as reduction and deoxygenation of different groups of organic compounds alkenes, alkynes, ethers, carbonyl compounds, esters, lactones, oxiranes, nitrogen, sulfur and halogen compounds, as well as dealkylation of tertiary amines. The method for preparation of the different oxygenated and reduced selenium and tellurium compounds are described, their reactions are reviewed, their usefulness in synthesis is indicated and more representative mechanisms are discussed.


Keywords:

organoselenium compounds;
organotellurium compounds;
oxidation;
reduction;
selenides;
selenium dioxide;
tellurides;
tellurium dioxide

G. Th. Mandryk

Papers

Über die Reaktion des Selendioxyds mit einigen Aryl‐Hydrazinen