A facile and convenient sequential homobimetallic catalytic approach towards β-methylstyrenes. A one-pot Stille cross-coupling/isomerization strategy

An efficient one-pot synthetic approach towards beta-methylstyrenes is reported. The transformation, based on sequential homobimetallic catalysis, involves a Stille cross-coupling reaction between aryl halides and allyltributylstannane, followed by an in situ palladium-catalyzed conjugative isomerization. The reaction was optimized, and the best results were obtained with 10 mol% Pd(PPh3)(2)Cl-2, 8.0 equiv. LiCl, and 0.5 equiv. PPh3 in diglyme at 130 degrees C for 12 h. It was demonstrated that the reaction tolerates a wide variety of functional groups.