Copper Iodide as a Recyclable Catalyst for Buchwald N-Arylation

An experimentally simple, efficient, and inexpensive catalyst system was developed for the N-arylation of indole, substituted indoles, pyrazole, imidazole, benzamide, morpholine, benzimidazole, thiobenzamide, aniline, benzylaniline, octylaniline, heptylaniline, and cyclohexylaniline with aryl iodides and bromides by using CuI as catalyst, trans-1,2-diaminocyclohexane (L1) as ligand, K2CO3 as base, and water as solvent at 80 degrees C. The yields were excellent, and the catalytic system was recyclable up to four times without loss of catalytic activity.