Stereospecific preparation of symmetrical (1Z,3Z) 2,3-difluoro-1,4-disubstituted-buta-1,3-dienes by the coupling reaction between bis(tributyltin) and high E/Z 1-bromo-1-fluoroalkenes

When the palladium-catalyzed coupling reaction of Bu3SnSnBu3 and high E/Z 1-bromo-1-fluoroalkenes is carried out at room temperature, symmetrical (1Z,3Z) 2,3-difluorinated-1,4-disubstituted-buta-1,3-dienes are successfully prepared in good yields.