Starting from a wide range of α-acylamino amide substructures synthesized using tritylamine as an ammonia surrogate in the Ugi reaction, Burgess-type reagents enable cyclodehydration and afford unprecedented oxazole scaffolds with four points of diversity, including a sulfamide moiety in the 5-position. The synthetic procedure employs readily available starting materials and proceeds smoothly under mild reaction conditions with good tolerance for a variety of functional groups, coming to fill a gap in the field of oxazole compounds.