Selenobenzophenones and Diazoalkanes: Isolation of Tetraarylethylenes by the Reaction of Benzophenone Hydrazones with Diselenium Dibromide.

Abstract

Selenobenzophenones react with diazomethanes to afford the corresponding diarylethylenes and symmetrical tetraarylethylenes. The reaction proceeds via 1,3,4-selenadiazoline intermediates which undergo retrocyclization. This is confirmed by isolation of three different types of tetraarylethylenes from diaryldiazomethanes and by formation of tetraarylethylenes from the reaction of benzophenone hydrazones with Se 2 Br 2 . -(OKUMA*, K.; KOJIMA, K.; OYAMA, K.; KUBO, K.; SHIOJI, K.; Eur. J. Org.