STILLE CROSS-COUPLING REACTIONS OF ARYL MESYLATES AND TOSYLATES USING A BIARYLPHOSPHINE BASED CATALYST SYSTEM

A catalyst system for the Stille cross-coupling reactions of aryl mesylates and tosylates is reported. Using the combination of Pd(OAc)(2), XPhos, and CsF in t-BuOH an array of aryl and heteroaryl sulfonates were successfully employed in these reactions. Morever, heteroarylstannanes, such as furyl, thienyl, and N-methylpyrrolyl, which are often prone to decomposition, were efficiently coupled under these conditions. Ortho-substitution on the stannane coupling partner was well tolerated; however, the presence of ortho substituents on the aryl sulfonates greatly reduced the efficiency of these reactions.