Radical carbodiazenylation - A convenient and effective method to achieve carboamination of non-activated olefins

Abstract

The regioselective addition of aryl and aryldiazenyl substituents to olefinic substrates can be described as carbodiazenylation. In this report we present our final results relating to this unique type of radical functionalization reaction, which has now been developed into a convenient, versatile and highly effective synthetic method. Starting from an investigation into rate constants for the addition of aryl radicals to monosubstituted, non-activated olefins, this key step is shown to be both fast and selective in mixtures of dimethyl sulfoxide and water. The by-products obtained in earlier reactions reveal that the main complication of carbodiazenylation is the formation of biaryl azo compounds. A careful adjustment of the carbodiazenylation procedure led to significantly improved results and now permits the synthesis of previously inaccessible products. New applications of carbodiazenylation such as the synthesis of 1,2-diazabutadienes, tetrahydropyridazines and substituted tricyclanes were investigated. Apart from this, we describe a convenient twostep sequence for intermolecular carboamination. © Wiley-VCH Verlag GmbH & Co. KGaA, 2008.