Cyanation of Aryl Chlorides Using a Microwave-Assisted, Copper-Catalyzed Concurrent Tandem Catalysis Methodology

A microwave-assisted, copper-catalyzed concurrent tandem catalytic (CTC) methodology has been developed for the cyanation of aryl chlorides, where the aryl chloride is first converted to an aryl iodide via halogen exchange and the aryl iodide is subsequently transformed to the aryl nitrile. A variety of aryl chlorides were converted to aryl nitriles in 44–97% yield using 20 mol % of CuI, 40 mol % of N,N’-cyclohexane-1,2-diamine, and 1.2 equiv of KCN in acetonitrile at 200 °C after 1–2 h. The same copper/ligand system served as a multifunctional catalyst for both steps of the concurrent catalytic process. Unlike our previously reported CTC hydrodehalogenation of aryl chlorides, CTC cyanation was catalytic in iodide. Kinetic simulations of the proposed CTC mechanism were consistent with experimental results and stipulate the relative reaction rates of the two catalytic cycles necessary to achieve reasonable yields of product.