Cross-coupling reactions of sterically hindered 2,2-difluoro-1-(aryl or silyl)ethenyl tosylates with (E)-arylethenylboronic acids

•Cross-coupling reactions between sterically hindered 2,2-difluoroethenyl tosylates with (E)-alkenylboronic acids•This alkenylation reactions are useful to prepare (E)-1,1-difluorobuta-1,3-diene derivatives•Straightforward preparation of (E)-2-(t-butyl)dimethylsilyl-4-aryl-1,1-difluorobuta-1,3-dienes and (E)-•2,4-diaryl-1,1-difluorobuta-1,3-dienes•This strategy has more advantages than the reactions between 2,2-difluoroethenyl halides and•alkenylboronic acids Cross-coupling reactions of sterically hindered 1-(t-butyldimethylsilyl)-2,2-difluoroethenyl tosylate 1 with (E)-arylethenylboronic acids in the presence of Pd(C6H5CN)2Cl2 (20 mol%), PCy3 (60 mol%) and K3PO4 (1.7 equiv) in dioxane/H2O (20/1) at 100 °C for 4-24 hours provided the corresponding (E)-4-aryl-2-(t-butyldimethylsilyl)-1,1-difluorobuta-1,3-dienes 2 in 43-90% yields. (E)-2,4-Diaryl-1,1-difluorobuta-1,3-dienes 4 were also prepared in 38-85% yields from the reaction of 1-aryl-2,2-difluoroethenyl tosylates 3a-c with (E)-arylethenylboronic acids in the presence of Pd(PPh3)2Cl2 (10 mol%) and PCy3 (20 mol%) under the similar reaction condition. [Display omitted]