B-Alkyl Suzuki−Miyaura Cross-Coupling Reactions with Air-Stable Potassium Alkyltrifluoroborates

The palladium-catalyzed cross-coupling reaction of substituted potassium alkyltrifluoroborates with aryl halides and aryl triflates proceeds readily with moderate to good yields. The potassium alkyltrifluoroborates 1, 2, and 3a-e were easily synthesized and obtained as air-stable crystalline solids that can be stored for long periods of time. All of the cross-couplings proceed under the same reaction conditions using PdCl(2)(dppf).CH(2)Cl(2) as catalyst in THF-H(2)O in the presence of 3 equiv of Cs(2)CO(3) as base.