Selenamide

Moreover, selenamides are more instable than thioamides so P2Se, was replaced by AljSe. In that case the cycle is less broken, but the yield of reaction is not as good. 

The reaction of primary amines with arenesulfenyl halides leads to the formation of sulfonamides (12). ° These compounds are most stable when the aryl group has electron-withdrawing substituents at Ae 2- and 4-positions. Selenamides are formed in an analogous manner but are somewhat less stable aliphatic amines give isolable compounds, but most anilines react with selenyl halides to give products of ring substitution. An example of an isolable selenamide is compound (13), which was prepared (79%) from the amine and 2-nitrobenzeneselenyl chloride. This compound was used as an intermediate in the preparation of 7a-methoxycephalosporins. 

The parent isoselenazolines and isoselenazolidines remain unknown because the selenamide Se-N bond is susceptible to cleavage followed by disproportionation. Only a few representatives of this class, substituted at the nitrogen and carbon atoms, have been reported. 

Zhang Y, Zhang H, Cui W, Chen H. Tandem MS analysis of selenamide-deiivatized peptide ions. J Am Soc Mass Spectrom. 2011 22 1610-21. 

Reference has already been made to recent reviews on selenazoles. Relatively little new work has appeared during the past two years. The Hantzsch synthesis has been adapted to the production of 2-thienyl (and furyl)selenazoles from the appropriate selenamides. - ... 

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