DELTA(3)-1,3,4-TELLURADIAZOLINES, A NOVEL TELLURIUM CONTAINING HETEROCYCLE - ONE-POT SYNTHESIS, STRUCTURE, AND REACTIVITY

The one-pot reaction of sterically hindered hydrazones with tellurium dichloride or tellurium tetrahalide in the presence of triethylamine i n benzene afforded Delta(3)-1,3,4-telluradiazolines 1, a novel heteroc ycle, via 1,3-dipolar cycloaddition of telluroketones and diazo compou nds, both generated in situ, The molecular structure of 1a was establi shed by X-ray crystallographic analysis. The photolysis of 1a led to i nstant and quantitative formation of the corresponding azine 8a, where as the thermolysis of 1a in the solid state afforded the corresponding retrocyclization products. (C) 1997 Elsevier Science Ltd.