[5+1] Cycloaddition of C,N-Cyclic N′-Acyl Azomethine Imines with Isocyanides

A catalyst-free [5 + 1] cycloaddition reaction between isocyanides and C,N-cyclic ff-acyl azomethine imines as the isocyanophile leading to novel heterocycles has been developed. These reactions proceeded quickly and cleanly to afford the corresponding imin-1,3,4-oxadiazin-6-one derivatives in high to excellent yields. A wide range of C,N-cyclic N-acyl azomethine imines and isocyanides were applicable to this reaction.