“…Actually, transition metal‐catalyzed diamidation of alkenes and ureas using phenyliodine(III) diacetate (PIDA) as oxidant was previously reported to synthesize imidazolidin‐2‐ones [16] . During the course of our studies on the reactions of various functionalized β‐oxoamides in the presence of different hypervalent iodine reagents, we developed efficient synthesis of a series of five‐ and six‐membered heterocycles, including pyrrolidin‐4‐ones, [17] pyrrolidin‐2,4‐diones, [18] dihydrooxazolo[4,5‐ c ]pyridine‐2,4,6(5 H )‐triones, [19] pyrazolin‐5‐ones, [20] isoxazoles, [21] isoxazol‐3(2 H )‐ones, [22] dihydrofuran‐3(2 H )‐ones, [23] oxazol‐2(3 H )‐ones, [24] and respectively. In our ongoing research on the reaction behaviour of β‐oxoamides towards different hypervalent iodine reagents in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU), we found that DBU played a role of reactant rather than an additive.…”