A combination of Pd 2 (dba) 3 ·CHCl 3 (0.5mol%) and commercially available, air-stable phosphonium salt [(t-Bu) 3 PH]BF 4 (1.4mol%) in a presence of Zn powder and Zn(CN) 2 as the cyanide source comprises an extremely efficient catalyst system for the cyanation of a diverse array of aryl bromides, at room temperature. This result emerged from an experimental strategy that combines the advantages of parallel, automated experimentation with the design of experiments (DOE) for the effective definition of an optimal set of reaction conditions.