- Photooxidation of triarylphosphines under aerobic conditions in the presence of a gold(iii) complex on cellulose extracted from Carthamus tinctorius immobilized on nanofibrous phosphosilicate
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Triarylphosphines were converted to the corresponding oxides via photooxidation as a novel method. In this study, cellulose was extracted from the Carthamus tinctorius plant and then oxidized by sodium metaperiodate. A gold complex was supported on this natural cellulose. Then, a gold complex on natural cellulose supported on FPS (FPS/Au(iii)) was synthesized for the reduction of phosphine oxides to corresponding phosphines with remarkable chemoselectivity. The morphology of FPS led to higher catalytic activity. FPS/Au(iii) NPs were thoroughly characterized using TEM, FESEM, FTIR, TGA, and BET.
- Sadeghzadeh, Seyed Mohsen,Zhiani, Rahele
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p. 1509 - 1516
(2019/01/24)
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- Visible light-induced 4-phenylthioxanthone-catalyzed aerobic oxidation of triarylphosphines
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We report herein a visible light-induced oxidation of triarylphosphines under aerobic condition with excellent functional group tolerance. In this transformation, the photo catalyst 4-phenylthioxanthone acted as a photosensitizer for the in situ generation of singlet oxygen. This new approach provided a cheaper and greener method for the preparation of phosphine oxide, showing great advantages in environmental protocols.
- Ding, Aishun,Li, Shijie,Chen, Yang,Jin, Ruiwen,Ye, Cong,Hu, Jianhua,Guo, Hao
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supporting information
p. 3880 - 3883
(2018/09/27)
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- Eosin Y-catalyzed photooxidation of triarylphosphines under visible light irradiation and aerobic conditions
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We report herein a novel method for Eosin Y-catalyzed photooxidation of triarylphosphines under visible light irradiation and aerobic conditions. This new approach employed visible light as the energy source and air as the oxidant, showing great advantages in environmental benignness and operational easiness with a wide functional group tolerance.
- Zhang, Yanbin,Ye, Cong,Li, Shijie,Ding, Aishun,Gu, Guangxin,Guo, Hao
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p. 13240 - 13243
(2017/03/09)
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- Palladium-catalyzed coupling reactions of bromo-substituted phenylphosphine oxides: A facile route to functionalized arylphosphine ligands
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The Heck reaction of OPPh3-n(4-C6H4Br) n (n=1-3) with electron deficient and neutral olefins led to linear olefin-substituted phenylphosphine oxides, whilst the reaction with an electron rich olefin in an ionic liquid solvent resulted in the formation of acetyl variants. The same bromophenylphosphine oxides also reacted with arylboronic acids under normal Suzuki coupling conditions, affording arylated phenylphosphine oxides in excellent yields. Amination and methoxycarbonylation of the bromophenylphosphine oxides by palladium catalysis were also shown to be feasible. Given that free phosphines can be readily derived from phosphine oxides, palladium-catalyzed coupling of OPR3-n(C6H4Br)n (R=alkyl, aryl) should provide a simple, yet versatile, route to functionalized phosphine ligands.
- Xu, Lijin,Mo, Jun,Baillie, Colin,Xiao, Jianliang
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p. 301 - 312
(2007/10/03)
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- Derivatized gold clusters and antibody-gold cluster conjugates
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Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be as small as 5.0 nm. Methods and reagents are disclosed in which antibodies, Fab' or F(ab')2 fragments thereof are covalently bound to a stable cl
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- N-Phenyl-P,P,P-triarylphospha-λ5-azenes, Triarylphosphines, and Triarylphosphine Oxides. Substituent Effects on 15N, 31P, and 13C NMR Spectra
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The syntheses and 15N, 31P, and 13C NMR spectra of a series of N-phenyl-P,P,P-triarylphospha-λ5-azenes 4 and the 31P and 13C NMR spectra of the corresponding series of triarylphosphines 5 and triarylphosphine oxides 6 are reported.The substituent effects on the chemical shifts can be best accommodated and rationalized by use of a model for system 4 whereby the dipole of the aryl group and its pendant R group polarizes the rest of the molecule.This includes the P and N atoms and phenyl ring, where an electron-withdrawing R group increases the electron density of the P, N, and ipso C-1 while decreasing the electron density on C-3 and C-4 of the N-phenyl ring (Figure 3).A similar polarization pattern for the phosphine oxide series 6 is suggested.In the phosphine series 5, the chemical shift data is consistent with the lone electron pair on the phosphorus atom delocalizing into the aryl rings.The coupling constant data, in particular 1JPN for series 4 and 1JPC for series 4-6, were examined with use of the Hammett monosubstituent parameter (MSP) and the Taft dual-substituent parameter (DSP) approaches.For systems 4 and 6, without a lone electron pair on the phosphorus atom, a better electron-donating substituent increases the one-bond P-C(Ar) coupling constant.On the contrary, in the phosphine series 5, where there is a lone electron pair on the phosphorus, a better electron-withdrawing substituent increases the one-bond P-C(Ar) coupling constant.DSP treatment of 1JPC, and comparing to the few related systems in the literature,shows three types of systems.One, which includes 4 and 6, has an atom, phosphorus in these cases, that does not have a lone pair of electrons attached to the ring to which is attached an atom with a lone pair of electrons.Here, the resonance effect on 1JPC predominates.A second series, which includes phosphines 5, has a lone pair on the atom attached to the aryl ring.In these cases, the resonance effect is ca. 50percent greater than the inductive effect.Finally, the third series, exemplified by two examples from the literature, has a tetrahedral atom (without a lone pair) attached to the aryl ring and this in turn is attached to tetrahedral atoms without lone electron pairs.In these case, the resonance and inductive effects are fairly comparable.
- Chou, Whe-Narn,Pomerantz, Martin
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p. 2762 - 2769
(2007/10/02)
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- The Mechanisms of the Conversion of Thiophosphoryl Compounds into their Phosphoryl Analogues by Photochemically Excited 3-Methylpyridazine 2-Oxide and by 2-Methyl-3-p-nitrophenyloxaziridine; a Comparison
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Reactions of tri-p-substituted triarylphosphine sulphides with 3-methylpyridazine 2-oxide, under photolysis, and with 2-methyl-3-p-nitrophenyloxaziridine both give the corresponding phosphine oxides.A detailed study and comparison of the two reactions shows that they are mechanistically quite distinct and that it is unlikely that the active oxygenating species generated by photolysis of the N-oxide, which attacks the phosphine sulphides, is an oxaziridine.The evidence presented suggests that this species may in fact be 'oxene'.
- Rowley, Alan G.,Steedman, John R. F.
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p. 1113 - 1120
(2007/10/02)
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