Perfluoropropenyl-containing phosphines from HFC replacements

Abstract

A series of new perfluoropropenyl-containing phosphines of the type R_3−nP(E-CFCFCF₃)_n (R = Ph, iPr, n = 1, 2; R = tBu, n = 2) have been prepared from the reaction of the hydrofluoroolefin Z-CF₃CFCFH (HFO-1225ye) with base and the appropriate chlorophosphine, while reaction with Cl₂PCH₂CH₂PCl₂ gave (CF₃CFCF)₂PCH₂CH₂P(CFCFCF₃)₂, the first example of a bidentate perfluoroalkenyl-containing phosphine. An alternative route to these phosphines based on the room- or low-temperature deprotonation of CF₃CF₂CH₂F (HFC-236ea) gives mainly the E-isomer, but also a small amount of the Z-isomer, the ratio of which depends on the reaction temperature. All of the phosphines could be readily oxidised with either H₂O₂ or urea·H₂O₂, and the phosphine selenides R_3−nP(Se)(E-CFCFCF₃)_n (R = Ph, n = 1,2; R = iPr, n = 1; R = tBu, n = 2) were also prepared. The steric and electronic properties of these ligands were determined based on their platinum(II), palladium(II) and molybdenum carbonyl complexes. The crystal structures of (CF₃CFCF)₂PCH₂CH₂P(CFCFCF₃)₂, (CF₃CFCF)₂P(O)CH₂CH₂P(O)(CFCFCF₃)₂, iPr₂P(Se)(CFCFCF₃)₂, trans-[PtCl₂{Ph_(3−n)P(E-CFCFCF₃)_n}₂] (n = 1 or 2), trans-[PdCl₂{R₂P(E-CFCFCF₃)}₂] (R = Ph, iPr) and [Mo(CO)₄{(CF₃CFCF)₂PCH₂CH₂P(CFCFCF₃)₂}] are reported.