A convenient method for intermolecular N-arylation of hydrazides with substituted aryl iodides in the presence of a copper catalyst and Cs(2)CO(3) is reported. The C-N coupling of N-Boc hydrazine with para- and meta-substituted aryl iodides afforded the N-arylated products A, regioselectively. A reversal in regioselectivity is observed for the arylation of benzoic hydrazide with ortho-substituted aryl iodides, providing the N'-arylated products B.
“Synthesis of N-Aryl Hydrazides by Copper-Catalyzed Coupling of Hydrazides with Aryl Iodides”, Org. Lett., 2001, 3(23), 3803-3805.