Synthesis of Electron-Deficient N1-(Hetero)aryl 3,3,5,5-Tetramethyl Piperazinones.

An alternative synthesis of N1-(hetero)aryl 3,3,5,5-tetra-substituted piperazin-2-ones is demonstrated using a copper-mediated Goldberg arylation of a common intermediate in good to fair yields. An improved synthesis of 3,3,5,5-tetramethyl piperazin-2-one is also described. This method allows for the synthesis of substituted piperazin-2-ones which are challenging or inaccessible using traditional Bargellini chemistry. [ABSTRACT FROM AUTHOR]