Cobalt-Catalyzed Electrophilic Amination of Aryl- and Heteroarylzinc Pivalates with N-Hydroxylamine Benzoates.

Aryl- and heteroarylzinc pivalates can be aminated with O-benzoylhydroxylamines at 25 °C within 2-4 h in the presence of 2.5-5.0 % CoCl2 ⋅2 LiCl to furnish the corresponding tertiary arylated or heteroarylated amines in good yields. This electrophilic amination also provides access to diarylamines and aryl(heteroaryl)amines. A new tuberculosis drug candidate (Q203) was prepared in six steps and 56 % overall yield by using this cobalt-catalyzed amination as the key step.