Construction of 1,3,4-oxadiazolines bearing CF 3 -quaternary centers via amino-assisted [3 + 2] cycloadditions.

An amino-assisted [3 + 2] cycloaddition strategy of nitrile imines with o -aminotrifluoroacetophenones has been explored, thus providing functionalized 1,3,4-oxadiazolines bearing CF 3 -quaternary centers in good to excellent yields in the presence of K 2 CO 3 under mild conditions. The amino groups located at the ortho -position of trifluoroacetophenone might play a crucial role in the present cyclization. The MTT assay shows that the 1,3,4-oxadiazoline derivatives could be potential candidates for the treatment of head and neck cancers.