Copper-Catalyzed Chemoselective Ring-Opening Hydroselenation and C–H Selenylation of Isoxazol-5-amines

Copper-catalyzed highly chemoselective transformations of isoxazol-5-amines have been developed. The first ring-opening hydroselenation of isoxazol-5-amines with selenols or RSeSeR/H₂O readily delivers 3-amino-2-selenoacrylamides in high yields, while the C-H selenylation of the substrates with diselenides at a low temperature produces 4-selenoisoxazoles with high efficiency. Both protocols demonstrate good functional group compatibility and mild reaction conditions under inexpensive copper catalysis. Mechanistic studies reveal that the presence of an amino group is indispensable for the successful implementation of the reactions.