Consecutive cross-coupling reactions of 2,2-difluoro-1-iodoethenyl tosylate with boronic acids: efficient synthesis of 1,1-diaryl-2,2-difluoroethenes

摘要

The cross-coupling reactions of 2,2-difluoro-1-iodoethenyl tosylate ( 2 ) with 2 equiv of boronic acids in the presence of catalytic amounts of Pd(OAc)₂ and Na₂CO₃ afforded the mono-coupled products 3 and 5 in high yields. The use of 4 equiv of boronic acids in the presence of catalytic amount of Pd(PPh₃)₂Cl₂ and Na₂CO₃ in this reaction resulted in the formation of symmetrical di-coupled products 4 in high yields. Unsymmetrical di-coupled products 4 were obtained in high yields from the reactions of 3 with 2 equiv of boronic acids in the presence of catalytic amounts of Pd(OAc)₂ and Na₂CO_3.