Construction of 5-Amino-1,2-Selenazole Scaffolds through N -Selenocyanation/Cyclization of Enaminones Using KSeCN.

A metal-free and mild approach for constructing 5-amino-1,2-selenazole skeletons by NBS/KSeCN-mediated N -selenocyanation and nucleophilic cyclization of β-enaminones has been developed. Various isoselenazole compounds and the isoselenazolyl derivatives of anti-inflammatory medicines, including isosepac, oxaprozin, and ibuprofen, have been obtained with good yields. This efficient, "one-pot", and atomic economy strategy may represent an alternative route for the construction of a 1,2-selenazole framework via the " + SeCN" pathway and provide new access to heterocycles containing a Se-N bond.