ChemInform Abstract: Synthesis and Reactivity of N-Selenoacylamidines - Precursors of Selenoheterocycles

A new synthesis and the reactivity of stable selenaazadienes are discussed. Their dienic, electrophilic and nucleophilic character are used to prepare five and six membered selenoheterocycles. The easy access to selenazine, selenazinone, selenopyran, selenazoline, selenazole and selenophene heterocycles from N-selenoacylamidines is described. An interpretation of the reactivity of the selenaazadiene systems, experimentaly compared to their thia analogues, is based on their physico-chemical parameters and correlated to the theoretical calculations of their frontier molecular orbital energy levels.