Synthesis of 2,5-difunctionalized pyridines via sequential chemoselective amination and Suzuki–Miyaura reactions

Pyridine derivatives are important building blocks in pharmaceutical and materials chemistry. Synthesis of 2-amino-5-(het)arylpyridine derivatives was explored via sequential chemoselective palladium-catalyzed amination and Suzuki–Miyaura cross-coupling reaction. 5-Bromo-2-tosyloxypyridine as a starting material, a new carbon–nitrogen bond was successfully formed chemoselectively on bromide over OTs group, followed by Suzuki–Miyaura couplings with various boronic acids to provide the desired 2-amino-5-(het)arylpyridines in moderate to excellent yields. Using this protocol, a valuable class of pyridine derivatives to be biologically active can be synthesized.