Nickel-mediated amination chemistry. Part 2: Selective N-arylation or N,N′-diarylation of piperazine

The 2,2′-bipyridine liganded Ni catalyst has revealed a good selectivity in the mono arylation of piperazine starting from aryl chlorides allowing a selective and efficient synthesis of N-arylpiperazines using stoichiometric amounts of reagents. The preparation of N,N′-diaryl substituted piperazines is also described.