Abstract: Hydroformylations of fluoro olefins, trifluoroprop-1-ene (TFP), pentafluorobut-1-ene (PFB), heptafluoropent-1-ene (HPFP), heptadecafluorodec-1-ene (HPDFD), vinyl fluoride (VF), pentafluorostyrene (PFS), and allylpentafluorobenzene (4a), promoted by transition- metal catalysts were studied. Remarkable dependency of the regioselectivity of the reaction on the catalyst metal species (Co, Pt, Ru, and Rh) was found in the reactions of TFP and ...