tert-Butyl Nitrite Mediated Synthesis of 1,2,4-Oxadiazol-5(4 H)-ones from Terminal Aryl Alkenes.

tert-Butyl nitrite (TBN) mediated synthesis of 3-aryl-1,2,4-oxadiazol-5(4 H)-ones has been accomplished using terminal aryl alkenes via a biradical reaction intermediate. Three consecutive sp2 C-H bond functionalizations of styrenes afforded 3-phenyl-1,2,4-oxadiazol-5(4 H)-ones via the formation of new C═N, C═O, C-O, and two C-N bonds. Both of the N atoms originate from TBN, while the carbonyl oxygen is from the water (moisture) the other oxygen from the N═O part of the TBN.