Efficient Synthesis of 2,2-Diaryl-1,1-difluoroethenes via Consecutive Cross-Coupling Reactions of 2,2-Difluoro-1-tributylstannylethenyl p-Toluenesulfonate

2,2-Difluoro-1-tributylstannylethenyl p-toluenesulfonate (2) was reacted with aryl iodides in the presence of 10 mol % of Pd(PPh3)(4) and 10 mol % of Cul in DMF at 80 degrees C for 10-20 h to give the cross-coupled products 3 in 35-97% yields. Further coupling reaction of 3 with arylstannanes in the presence of 5 mol % of Pd(PFh(3))(4) and 3 equiv of LiBr in DMF at 100 degrees C for 2-24 h afforded the desired products 5 in 25-78% yields.