Ni-Catalyzed Alkylative Dimerization of Vinyl Grignard Reagents Using Alkyl Fluorides

Alkyl halides underwent unique cross-coupling reaction with vinylmagnesium chloride in the presence of Ni catalyst to give 2-alkyl-3-butenyl Grignard reagent (1) in high yields. This reaction proceeded efficiently at 25 degrees C in THF using primary and secondary alkyl fluorides. On the other hand, PhCH=CHMgBr gave double alkylative vinyl coupling product 4 in good yield as the sole coupling product. Alkyl fluorides react as the most suitable alkylating reagent in comparison to the corresponding chlorides, bromides, and iodides.