Potassium trifluoro(4-phenoxyphenyl)borate serves as a stable boronate nucleophile in palladium-catalyzed cross-coupling reactions, notably the Suzuki-Miyaura coupling, with aryl or heteroaryl halides to synthesize substituted biaryls. Its trifluoroborate structure provides enhanced air and moisture stability over traditional boronic acids, preventing protodeboronation and enabling use in diverse solvents including water. This reagent is essential for constructing complex aromatic frameworks in pharmaceutical intermediates, agrochemicals, and organic materials for electronics.