A general method for the N-arylation of indoles using catalysts derived from Cul and trans-1,2-cyclohexanediamine, trans-N,N'-dimethyl-1,2-cyclohexanediamine, or N,N'-dimethyl-ethylenediamine is reported. N-Arylindoles can be produced in high yield from the coupling of an aryl iodide or aryl bromide with a variety of indoles.
“The Copper-Catalyzed N-Arylation of Indoles”, J. Am. Chem. Soc., 2002, 124(39), 11684-11688.