Palladium-catalyzed cross-coupling reactions of substituted aryl(dimethyl)silanols

Cesium carbonate and cesium hydroxide monohydrate are effective activators for the palladium-catalyzed cross-coupling of aryl(dimethyl)silanols with substituted aryl halides. Extensive optimization studies led to the identification of key variables (solvent, catalyst, additive, and hydration level) that influence the rate and selectivity of the process. Manipulation of these factors provides an effective coupling method of wide scope and generality. Electron-rich aryl(dimethyl)silanols undergo cross-coupling with aryl iodides and aryl bromides in high yields and high selectivity for the desired cross-coupling products. Alternatively, high yields of cross-coupling products could be obtained with electron-poor or ortho-substituted aryl(dimethyl)silanols when activated with cesium hydroxide monohydrate.