Isoselenocyanates as building blocks for selenium-containing heterocycles

Isoselenocyanates are conveniently accessible from elemental selenium in safe and efficient reactions. They can be used either as reactive intermediates or as relatively stable and storable starting materials for the preparation of selenaheterocycles or heterocyclic selones. In most cases, the reactions are initiated by a nucleophilic attack onto the isoselenocyanate, followed by a cyclization via the Se-or the N-atom. Alternatively, the intermediate adduct of the nucleophile and the isoselenocyanate can undergo a second nucleophilic addition with a third compound and subsequent cyclization.