N-Substituted 2-Aminobiphenylpalladium Methanesulfonate Precatalysts and Their Use in C-C and C-N Cross-Couplings

A series of phosphine-ligated palladium precatalysts based on N-methyl- and N-phenyl-2-aminobiphenyl have been developed. Substitution at the nitrogen center prevents the presence of traces of aminobiphenyls that contain a free -NH2 group from contaminating cross-coupling products. These precatalysts produce N-substituted carbazoles upon activation, which cannot consume starting materials. These precatalysts were efficiently generated from 2-aminobiphenyl with minimal purification and found to be highly effective in Suzuki-Miyaura and C-N cross-coupling reactions.