Prototropy in HPCC triad of alkyl(α-ethoxyethenyl)phosphines

Intramolecular Dehydrofluorinative Coupling of the Asymmetric Diphosphine Ph2PCH2CH2PPh(C5F4N-4) and Pentamethylcyclopentadienyl Ligands in a Rhodium Complex

“…15 The resonance of the PPh(C 5 F 4 N-4) phosphorus atom occurs at δ -20.3 and shows a coupling to two fluorine atoms of 19 Hz. The value of δ is similar to those of 2 (δ -18.9), 10 18 Despite contamination by dppe, 1 was found to be amenable to further reaction. The tetrafluoropyridyl group is more electron-withdrawing than pentafluorophenyl, 12 and so phosphines bearing the former might be expected to be less basic than those bearing the latter.…”

“…2%), from which it could not be separated. The phosphine Ph 2 P(C 5 F 4 N-4), 2, 10 terization of 1 was based on NMR spectroscopy and mass spectrometry. The resonance of the PPh 2 phosphorus atom occurs at δ -11.3, which is similar to that of δ -12.5 for dppe.…”

“…During this study we found that on exposure to air for several weeks phosphine 2, a pale yellow oil, deposited colorless crystals of OPPh 2 (C 5 F 4 N-4), 4. 10 Phosphine oxide 4 was characterized by mass spectrom-etry and NMR spectrometry. (Although 4 has been prepared previously, only the 31 P NMR data were reported.…”

“…(Although 4 has been prepared previously, only the 31 P NMR data were reported. 10 ) In addition the structure of 4 was determined by single-crystal X-ray diffraction. There are two molecules in the asymmetric unit; the structure of one is shown in Figure 1.…”

“…Phosphine 2 was prepared as described. 10 1 H (CDCl3): δ 7.43 (m, 10H, C6H5). 19 F (CDCl3): δ -91.46 (m, 2F, Fmeta-P), -131.40 (m, 2F, Fortho-P).…”