Copper-catalyzed three-component formal [3 + 1 + 2] annulations for the synthesis of 2-aminopyrimidines from O-acyl ketoximes.

A copper-based catalytic system has been developed to enable formal [3+1+2] annulations of ketoxime acetates, aldehydes, and cyanamide. This protocol offers a new strategy for the synthesis of highly substituted 2-aminopyrimidine compounds, and more importantly, pyrimidines have now been included into the N-heterocycle family constructed using O-acyl ketoximes as N-C-C synthon.