Selenium‐Containing Heterocycles from Isoselenocyanates: Synthesis of 1,3‐Selenazinane and 1,3‐Selenazinanone Derivatives

The reaction of the intermediate ketene N,Se‐hemiacetal 3 , prepared from cyanomethylene derivatives 1 by treatment with Et 3 N and aryl isoselenocyanates 2 , with bis‐electrophiles 6, 7, 9 , and 11 in DMF affords tetrahydro‐1 H ‐1,3‐selenazine (=1,3‐selenazinane) derivatives 8, 10 , and 12 in good yield ( Scheme 2 and Tables 1–3 ). Chemical and spectroscopic evidence for the structures of the new compounds are described. The structures of 8d and 12e are established by X‐ray crystallography ( Figs. 1 and 2 ).