High-Throughput Screening Protocol for the Coupling Reactions of Aryl Halides Using a Colorimetric Chemosensor for Halide Ions

Mercury complex of 4-(2-pyridylazo)resorcinol (PAR-2Hg2+), a halide-ion chemosensor, was prepared and its efficiency as a tool for high-throughput screening (HTS) of transition-metal-catalyzed coupling reactions was investigated. It showed a high selectivity for halide ions. When the PAR–2Hg2+ complex was used in the Suzuki coupling reaction and C–H activated coupling reaction with aryl bromides, the quantitative and qualitative conversions of aryl halides were obtained from the reaction mixture color change.