262425-56-9Relevant academic research and scientific papers
Phosphinodefluorination of polyfluorobenzenes by silylphosphines Ph(R)PSiMe3 (R = Me, Ph): Further experimental and computational evidences for the concerted ANDN mechanism of aromatic nucleophilic substitution
Zhivetyeva,Goryunov,Bagryanskaya,Grobe,Shteingarts,Würthwein
, p. 58 - 69 (2014/07/08)
Trimethylsilylphosphines PhRPSiMe3 (1 R = Me, 2 R = Ph) have been shown to phosphinodefluorinate 1,2,3- (3), 1,3,5- (4) and 1,2,4-trifluorobenzene (5) in benzene solution or without solvent at 150-200 °C to form the respective (difluorophenyl)methylphenyl- and -diphenylphosphines in high NMR yields under harder conditions compared to the previously reported reactions of Me2PSiMe3 with the same substrates. Hexafluorobenzene (6), pentafluorobenzene (7) (at 150 °C), octafluorotoluene (8) and pentafluoropyridine (9) (at 20 °C) react with phosphine 2 without a solvent almost quantitatively under fluorine 1,4-disubstitution (for 6) or monosubstitution (for 7-9) by the Ph2P group to give the corresponding (polyfluoroaryl)diphenylphosphines in 50-60% (for 6-8) and 95% (for 9) isolated yields. The regio and substrate selectivities exhibited by 3-5 in the reactions of the single substrates and in competitive reactions of 3 vs. 4 with 1 or 2 and 4 vs. 5 with 2 indicate relative fluorine substituent rate factors fo-F > fm-F consistent with the concerted ANDN mechanism which is supported by high level quantum chemical DFT-studies for the reactions of the substrates 3 and 4 with 1, 2 and 10 as well as for 6 with 2.
Peri-interactions in naphthalenes, 21. Substituent effects in (8-dimethylamino-naphth-1-yl)-and [2-(dimethylamino-methyl)phenyl]-phosphines on the 31P-NMR signal positions
Schiemenz, Guenter Paulus
, p. 185 - 202 (2007/10/03)
Contrary to claims in the literature, the 31P NMR signal positions of ortho-dimethylaminomethyl-substituted triarylphosphines do not provide evidence for hypercoordination at phosphorus; the observed highfield shifts relative to triphenylphosphine are rather due to the ortho-effect. In (8-dimethylamino-naphth-1-yl)phosphines, the signal positions similar to that of triphenylphosphine are the result of the highfield ortho-effect and a lowfield peri-substituent effect of about the same magnitude whose nature remains to be explored.
Structural and electronic impact of fluorine in the ortho positions of triphenylphosphine and 1,2-bis(diphenylphosphino)ethane; a comparison of 2,6-difluorophenyl- With pentafluorophenylphosphines
Corcoran, Christopher,Fawcctt, John,Friedrichs, Steffi,Holloway, John H.,Hope, Eric G.,Russell, David R.,Saunders, Graham C.,Stuart, Alison M.
, p. 161 - 172 (2007/10/03)
The new fluorine-containing phosphines PPh2(C6H3F2-2,6) I and PPh(C6H3F2-2,6)2 II were synthesized in high yield from C6H3BrF2-2,6 and PPh2Cl or PPhCl2. Phosphines I, II and the previously reported P(C6H3F2-2,6)3 III have been structurally characterized by single-crystal X-ray diffraction. A range of transition metal complexes of I-III and the diphosphine (C6H3F2-2,6)2PCH2CH 2P(C6H3F2-2,6)2 have been prepared and their spectroscopic properties compared with those of the analogous complexes of the pentafluorophenylphosphines PPhx(C6F5)3-x(x = 0-2) and the diphosphine (C6F5)2PCH2CH2P(C 6F5)2. The structures of trans-[PtCl2(PEt3){PPhx(C6H 3F2-2,6)3-x}] (x = 2,1 or 0), trans-[MCl(CO){PPh(C6H3F2-2,6) 2}2] (M = Rh or Ir), trans-[IrCl{(CO){P(C6H3F2-2,6) 3}2] and trans-[PtCl2{PPh-(C6H3F2-2,6) 2}2] have been determined by single-crystal X-ray diffraction. The spectroscopic and structural data indicate that the 2,6-difluorophenylphosphines are more basic than the analogous pentafluorophenylphosphines and exert a similar or slightly smaller steric influence. The Royal Society of Chemistry 2000.
