- Phosphorus halides complexes with 4-dimethylaminopyridine and N-methylimidazole
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Formation of complexes between phosphorus halides and 4- dimethylaminopyridine or N-methylimidazole was studied. The following phosphorus halides: trichloride, oxychloride, and sulfochloride, were found to form equilibrium mixtures of the complexes containing different numbers of the ligand molecules. Among the studied phosphorus halides only pentachloride and tribromide form stable complexes with a constant composition.
- Bezgubenko,Pipko,Sinitsa
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- Silver-Catalyzed Regioselective Phosphorylation of para-Quinone Methides with P(III)-Nucleophiles
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A simple and efficient method for the silver-catalyzed regioselective phosphorylation of para-quinone methides (p-QMs) with P(III)-nucleophiles (P(OR)3, ArP(OR)2, Ar2P-OR) has been established via Michaelis-Arbuzov-type reaction. A broad range of P(III)-nucleophiles and para-quinone methides are well tolerated under the mild conditions, giving the expected diarylmethyl-substituted organophosphorus compounds with good to excellent yields. Moreover, a series of corresponding enantiomers can be obtained by employing dialkyl arylphosphonite (ArP(OR)2) as substrates. The control experiments and 31P NMR tracking experiments were also performed to gain insights for the plausible reaction mechanism. This protocol may have significant implications for the formation of C(sp3)-P bonds in Michaelis-Arbuzov-type reactions.
- Liu, Yu,Tang, Ke-Wen,Wong, Wai-Yeung,Xie, Jun,Xiong, Biquan,Xu, Shipan,Xu, Weifeng
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p. 14983 - 15003
(2021/11/12)
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- Synthesis of tervalent phosphorus esters in biphasic system using potassium phosphate as unique solid base
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The synthesis of tervalent phosphorus esters continues to be a significant area of interest, much of it again directed toward the synthesis of phosphite ligands for metal-catalyzed reactions. Typically, they were obtained through esterification of the corresponding phosphorus chlorides with the appropriate alcohols in the presence of an amine. In this paper, we present a new method for the synthesis of tervalent phosphorus esters, not yet mentioned in the literature, when potassium phosphate, as a unique base, is used in liquid-solid system. Symmetrical and unsymmetrical phosphites were obtained with good yields (65%-80%) using this method. The compounds were characterized by 31P NMR spectroscopy.
- Ilia, Gheorghe,Iliescu, Smaranda,Macarie, Lavinia,Popa, Adriana
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p. 360 - 364
(2008/09/20)
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- 11,12-cyclic phosphite or phosphate derivatives of erythromycin and related macrolides
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Disclosed are the antibacterial compounds having the formulas: STR1 or pharmaceutically acceptable salts and esters thereof. Also disclosed are the processes for preparing compounds of formulas (I), and II) of the invention, pharmaceutical compositions comprising a therapeutically effective amount of a compound of the invention in combination with a pharmaceutically acceptable carrier, as well as a method for treating bacterial infections by administering to a mammal a pharmaceutical composition containing a therapeutically-effective amount of a compound of the invention.
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- 2,4-diphosphoranediyl-l,3-diphosphetanes
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The 1,3-dichloro- and 1,3-dibromo-substituted title compounds 5b, c result from the condensation of triphenylphosphonium-bis(trimethylsilyl)methylide 1 with PC13 and PBr3. The chloro derivative 5b undergoes a variety of single and double substitution reactions, of which some have merely been tested and others have been made preparative use of. The substitution of one chloride by an ylidyl, amino, phosphino, or metal carbonyl group is accompanied by the spontaneous dissociation of the other P-C1 bond to yield the 1,3-diphosphetenium chlorides 14/15, 19, 31 and 36, respectively. In other cases (9, 27, 32) dissociation can be achieved by means of a Lewis acid. Protonation of 5b occurs at the carbon ring members; methylation and formation of transition metal complexes occurs at a phosphorus ring member. PC13 degrades the four-membered ring of 5b or enlarges the ring to yield 3,5-diphosphoranediyl-l,2,4-triphospholane derivatives 39, 40, 42. Keywords: Phosphorus / Heterocycles / Phosphorus ylides / Phosphoranediyl and phosphonio substituants / P-C1 bond dissociation WILEY-VCH Verlag GmbH.
- Schroedel, Hans-Peter,Schmidpeter, Alfred
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p. 1519 - 1527
(2007/10/03)
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- The kinetics and mechanism of the reaction of trimethyl phosphite with benzylideneacetophenones
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The kinetics and mechanism of the equilibrium reaction of benzylideneacetophenones 4 with trimethyl phosphite (TMP) to yield, 2,2,2-trimethoxy-2,3-dihydro-1,2λ5-oxaphospholes 5 are reported. The second-order rate constants for the formation of 5 were determined using a polarographic method and the rate constants for the decomposition reaction were calculated from the equilibrium constants. The linear Hammett plots in some cases and the curved ones in others indicate that the rate-determining step depends on the character of the ring substituants in 4 and 5. A thermodynamic study of the forward reaction showed a relatively small enthalpy and a large negative entropy of activation in agreement with the existence of a strongly polarised and/or crowded structure in the transition state. The proposed mechanism, in cases where electron-donating substituents (Y) or hydrogen are on the aromatic ring next to the carbonyl carbon or where electron-donating substituents (X) are on the aromatic ring next to the double bond, involves nucleophilic attack of phosphite on the carbonyl carbon atom in the rate-limiting step to form intermediate I2 followed by a ring closure to an oxaphosphirane I2 and ring enlargement to the oxaphospholene 5. The use of electron-withdrawing substituents (both for X and Y) results in a change in the reaction pathway in which phosphite attacks the carbon atom β to the carbonyl group in the rate-limiting step followed by a fast ring closure of I3 to oxaphospholene 5.
- Petnehazy, Imre,Clementis, Gyoergy,Jaszay, Zsuzsa M.,Toeke, Laszlo,Hall, C. Dennis
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p. 2279 - 2284
(2007/10/03)
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- Phosphitylation via the Mitsunobu reaction
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Treatment of a dialkyl phosphite with triphenylphosphine and diisopropyl azodicarboxylate in toluene, followed by addition of an alcohol, results in the formation of the corresponding trialkyl phosphite. Similarly, dialkyl phosphonites can be synthesised from monoalkyl phosphites (alkyl phosphinates).
- Grice, I. Darren,Harvey, Peta J.,Jenkins, Ian D.,Gallagher, Michael J.,Ranasinghe, Millagahamada G.
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p. 1087 - 1090
(2007/10/03)
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- Route to glycals in the allal and gulal series
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Axial anomeric sulfoxides generated via thiophenol Ferrier rearrangement of glucal and galactal derivatives are used to synthesize glycals of the gulal and allal series. An application of the method led to the synthesis of the esperamicin thiosugar.
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- PROTONATED AMINOPHOSPHINES
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The possibility to obtain pure salts of tetrafluoroboric acid with aminophosphines is proved.It is shown by means of NMR spectroscopy and X-ray analysis that the protonation occurs at the phosphorus atom only.All aminophosphonium salts prepared appear not to phosphorylate nucleophiles, whereas phosphorylation occurs when some bases turning the phosphonium salts into H-complexes are added. Key words: Phosphorylation; nucleophiles; protonation; catalysis; aminophosphines; spectroscopy.
- Nifantyev, E. E.,Gratchev, M. K.,Burmistrov, S. Yu.,Antipin, M. Yu.,Struchkov, Yu. T.
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p. 159 - 174
(2007/10/02)
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- OXIDATIVE ALKOXYLATION OF PHOSPHINE IN ALCOHOLIC SOLUTIONS OF PLATINUM(IV) HALIDE COMPLEXES
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Platinum(IV) halide complexes are shown for the first time to undergo fast reduction in alcohols (MeOH, EtOH, PrOH, BuOH, and i-AmOH) at 298-323 K under the action of PH3 to Pt(II)halide complexes with the highly selective formation of the corresponding trialkyl phosphites.The products of O-phosphorylation of the alcohols are studied by GLC and 31P NMR and IR spectroscopy.The intermediate compounds were studied by x-ray microanalyses and x-ray photoelectron and UV spectroscopy.The reaction is promoted by Pt(II) compounds and retarded by H2O and acids.The complex Pt(IV) chlorides are reduced more slowly than the mixed chloride bromide and especially chloride complexes.The kinetics and mechanism of this new reaction are discussed.
- Dorfman, Ya. A.,Levina, L. V.,Aibasov, E. Zh.
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p. 1847 - 1859
(2007/10/02)
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- PHOSPHORYLATED ALKOXYACETYLENES. VIII. SYNTHESIS AND PROPERTIES OF (ALKOXYETHYNYL)PHOSPHONITES
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(Alkoxyethynyl)phosphonites, which have not been known previously, are stable only in solution, are capable of undergoing isomerization into (carbonylmethylene)phosphoranes, readily disproportionate with the formation of trialkyl phosphites, and take up nucleophilic reagents at the triple bond.
- Lukashev, N. V.,Fil'chikov, A. A.,Kozlov, A. I.,Luzikow, Yu. N.,Kazankova, M. A.
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p. 1600 - 1603
(2007/10/02)
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- Unsaturated amino acids
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The invention relates to unsaturated amino acids of the formula I STR1 in which R1 represents hydroxy or etherified hydroxy, R2 represents hydrogen, alkyl, hydroxy or etherified hydroxy, R3 represents hydrogen, alkyl, haloalkyl, hydroxyalkyl, lower alkoxyalkyl, arylalkyl, lower alkenyl, halogen or aryl, R4 represents hydrogen, alkyl or aryl, R5 represents hydrogen or alkyl, R6 represents carboxy or esterified or amidated carboxy, R7 represents amino or amino substituted by alkyl or acyl, A represents unsubstituted or alkyl-substituted α,ω-alkylene having from 1 to 3 carbon atoms or represents a bond, and B represents methylene or a bond, with the proviso that A is other than a bond when B represents a bond, and salts thereof. They can be manufactured, for example, in accordance with the Michaelis-Arbuzov reaction and can be used as pharmacologically active substances.
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- DISPLACEMENT RATE OF ARYLOXY SUBSTITUENTS IN CYCLIC AND ACYCLIC TRIPHOSPHITES BY METHOXIDE IONS, AND WATER
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The displacement rate of aryloxy substituents by methoxide ions in the following triphosphites: 2-phenoxy-1,3,2-dioxaphospholane (I), 2-methoxy-benz-1,3,2-dioxaphospholene (II), and dimethyl phenylphosphite (III), is for each phosphite higher in methanol than in dichloromethane.On the other hand, dichloromethane discriminates much more strongly between five-membered cyclic and acyclic phosphites than methanol, as shown by the following rate ratios cyclic/acyclic in CH3OH: I/III = 13, II/III = 2; and in CH2Cl2: I/III = 1.8 x 103, II/III = 1.1 x 103. Water, as nucleophile towards the same phosphites in deuteroacetone, appears to exhibit somewhat similar magnitude of discrimination as methoxide in methanol. Key Words: Cyclic and acyclic triphosphites; displacement rate of aryloxy substituents.
- Aksnes, Gunnar,Froeyen, Paul
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- Novel ylide-type rhodium complexes containing a six-membered RhCH2PR2CH2CH2PR2 ring
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The chelate rhodium(I) complexes C5H3Rh[1,2-C2H4(PR2) 2] (2, R = Ph; 3, R = Me) have been prepared from [L2RhCl]2 (L = C2H4, C8H14), the diphosphine (dppe or dmpe), and MC5H5 (M = Na, Tl). Compounds 2 and 3 react with CH2I2 by oxidative addition to give the (iodomethyl)rhodium(III) compounds [C5H5RhCH2I(1,2-C2H 4(PR2)2)]I (4a, 5a) which have been converted by reaction with NH4PF6 to the more stable PF6 salts 4b and 5b. Whereas 4b is completely inert in nitromethane solution, 5b on addition of NEt3 isomerizes quantitatively to give the metallaheterocycle [C5H5(I)RhCH2PMe2CH 2CH2PMe2]PF6 (7). The corresponding dicationic derivative [C5H5(PMe3)RhCH2PMe 2CH2CH2PMe2](PF6) 2 (8) is obtained by ligand exchange. The molecular structure of 7 has been determined by X-ray analysis. Compound 7 crystallizes in the space group P21/n with a = 848.2 (2) pm, b = 1489.5 (4) pm, c = 1594.6 (4) pm, and β = 103.17 (2)°. The six-membered ring in the cation of 7 adopts a chair conformation. Complex 7 has also been prepared from C5H5RhCH2I[P(OMe)3]I and dmpe in the presence of NH4PF6. In contrast, the analogous (iodomethyl)rhodium compound C5H5RhCH2I(PMe3)I reacts with dmpe (and NH4PF6) to produce a dinuclear-bridged species which presumably has the composition {[C5H5(PMe3)(I)Rh]2(μ-CH 2PMe2CH2CH2PMe2CH 2)}(PF6)2 (9). The cobalt complexes C5H5Co(dmpe) (12), [C5H5(CO)Co]2(μ-dmpe) (13), C5H5Co(CO)(η1-dppm) (14), and [C5H5CoCOCH3(η2-dppm)]I (15) also have been prepared by using either C5H5Co(PMe3)2 or C5H5Co(CO)2 as starting material.
- Werner, Helmut,Hofmann, Lothar,Paul, Wilfried,Schubert, Ulrich
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p. 1106 - 1111
(2008/10/08)
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- Reactive E=C(p-p)?-Systems, VI. Reactions of the Phosphaalkene F3CP=CF2 with H Acidic Compounds
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The reactions of the perfluorophosphaalkene F3CP=CF2 (1) with HX compounds proceed via addition to the PC double bond yielding either secondary phosphanes F3CP(H)CF2X (X = OH, OR, NR2, PMe2) or PX derivatives F3CP(X)CF2H (X = Cl, Br, SMe, SeMe, AsMe2).The rate of reaction with H2O is strongly pH-dependent, but only at pH > 13 the opposite direction of addition is observed.Similar results are obtained for the addition of alcohols, for which the presence of OR(-) results in two effects: (i) Reversion of the addition direction to yield F3CP(OR)CF2H; (ii) HF elimination from F3CP(H)CF2OR to give substituted phosphaalkenes.With strong bases HNR2, the addition is followed immediately by HF elimination producing the surprisingly stable phosphaalkenes F3CP=C(F)NH2 (R = Me, Et).Secondary phosphanes of the type F3CP(H)CF2X (X = OMe, OEt, PMe2) are found to be suitable precursors for the preparation of novel heterosubstituted derivatives of 1 by elimination of HF with NMe3.New compounds were characterized by NMR, MS, GC/MS and GC/IR measurements. - Keywords: HX Addition to F3CP=CF2, New Chiral CF3 Substituted Phosphanes, Phosphaalkenes, Mass Spectra, NMR Spectra
- Grobe, Joseph,Van, Duc Le,Nientiedt, Juergen
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p. 149 - 161
(2007/10/02)
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- Diels-Alder Adducts of the Diphosphene F3CP=PCF3
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The heterocycles 3 to 6 are formed in a one-pot procedure by reacting trifluoromethyl phosphorus diiodide F3CPI2 with tin dichloride SnCl2 in the presence of the corresponding 1,3-dienes.The reactions proceed via cycloaddition of the diphosphene intermediate F3CP=PCF3 (1) as suggested by the high yields obtained (50 to 100percent) and the formation of the cyclic tetraphosphane (F3CP)4 (2) as the only by-product.Cycloreversion occurs at moderate temperatures as demonstrated by the reaction of 6 with 2,3-dimethylbutadiene to give 3 and cyclohexadiene.The products have been characterized by NMR and mass spectra. - Key words: Perfluoromethyl Diphosphene, Preparation (in situ), Cycloaddition, Mass Spectra, NMR Spectra
- Grobe, Joseph,Van, Duc Le,Schulze, Joachim
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p. 1753 - 1755
(2007/10/02)
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- Preparation and Structure of Certain Phosphorus-centred Radical Cations
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Exposure of dilute solutions of various trivalent phosphorus derivatives, PL3, in fluorotrichloromethane to (60)Co γ-rays at 77 K gave the corresponding cations, (1+), characterised by their e.s.r. spectra.The spectra establish that the SOMO for these cations is considerably localised on phosphorus, which contributes extensive atomic 3s and 3p character.The results confirm and extend previous studies using sulphuric acid matrices.The tendency for these cations to react with corresponding neutral molecules to give ?* dimer-cations PL3>(1+) is also confirmed. The structures of these species are discussed and compared with those of related radicals.
- Hasegawa, Akinori,McConnachie, Glen D. G.,Symons, Martyn C. R.
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p. 1005 - 1016
(2007/10/02)
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- Element-Organic Amine/Imine Compounds, XXIII. Rotamers of Aminophosphanes and Aminophosphoranes
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The diazaphosphasiletidines 3a - h can be synthesized from R2Si(NCR3Li)2 and Cl2PNR1R2 (1) as well as from (2) and MNR1R2 (R = CH3).At ambient temperature they show hindered rotation about the P - NR1R2 bond. 3g is separated as a pair of E/Z-rotamers, whose structure has been elucidated by NMR and X-ray analyses.The kinetically measured P - N rotation barriers (ΔG* ca. 30 kcal/mol) are until now the highest that have been measured.The isomerization of 3g (E) -> 3g(Z) (P - N rotation, P inversion, or both) is a P - N rotation which has been established by the synthesis and the NMR spectroscopically measured rearra ngement of (3i) (R = CH3, four isomers).The interaction of 3a - h with sulfur, selenium, and methyl iodide gives 4 - 6a - h.Below 0 deg C they all show hindered rotation about the P - NR1R2 bond. 4 and 5 are suitable for the study of the structure dependence of 1H NMR ASIS effects.The oxidation of 3g(E/Z) to the isomers 4g - 6g(E/Z) occurs with retention of configuration.These compounds show significant differences with respect to their thermal stability and their reaction with methanol.The comparison of the ΔG* values of the P - N rotation barriers of 3 - 6 shows that the steric influence of the exo-amino substituents R1 and R2 is most important.The E/Z equilibrium of the unsymmetrically substituted compounds gives evidence that the two ground states of P - N rotation are mostly sterically, possibly also electronically.
- Scherer, Otto J.,Puettmann, Michael,Krueger, Carl,Wolmershaeuser, Gotthelf
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p. 2076 - 2124
(2007/10/02)
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- LIGAND DISSOCIATION FROM MONO-SUBSTITUTED DERIVATIVES OF HEXACARBONYLCHROMIUM (Cr(CO)5L, L = P(C6H5)3, P(C4H9)3, P(OCH3)3, P(OC6H5)3, AND As(C6H5)3)
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The rates of dissociation of the unique ligand from Cr(CO)5L have been determined for L = P(C6H5)3, P(OC6H5)3, P(OCH3)3, and As(C6H5)3 by reaction with CO.The reactions were investigated from 80-140 deg C and activation parameters were determined.The rate
- Wovkulich, Michael J.,Atwood, Jim D.
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- ALKYL ARYL BROMOPHOSPHATES: NOUVEAUX REACTIFS DE PHOSPHORYLATION
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La reaction des bromophosphates (5) avec le 5'-O-monomethoxytritylthymidine dans la pyridine conduit facilement soit au nucleoside-3'-phosphotriester (7), soit au nucleoside 3'-phosphodiester (8) selon l'ordre d'addition des reactifs.
- Thuong, N. T.,Chassignol, M.
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p. 2063 - 2066
(2007/10/02)
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- Properties and Reactions of Trimethyl Phosphite, Trimethyl Phosphate, Triethyl Phosphate, and Trimethyl Phosphorothionate by Ion Cyclotron Resonance Spectroscopy
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The gas-phase ion-molecule reactions occurring in trimethyl phosphite, trimethyl phosphate, triethyl phosphate, and trimethyl phosphorothionate have been investigated by ion cyclotron resonance spectroscopy.Protonated parent ions, tetracoordinated phosphonium ions, and cluster ions are the reaction products observed.The proton affinities of these compounds have been determined to be 222.9, 214.2, 218.7, and 216.6 kcal/mol, respectively (relative to PA(NH3) = 207.0 kcal/mol).Homolytic bond dissociation energies of the protonated species are calculated using adiabatic ionization potentials determined by photoelectron spectroscopy.The trends in these quantities are discussed.A reasonable value for the correlated homolytic bond dissociation energy of trimethyl phosphite indicates that the first ionization potential of this molecule should be assigned to the phosphorus lone pair.The application of chemical ionization mass spectrometry to the analysis of phosphorus esters is briefly discussed.
- Hodges, Ronald V.,McDonnell, T. J.,Beauchamp, J. L.
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p. 1327 - 1332
(2007/10/02)
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- HYDROLYSE ET ALCOOLYSE DE SPIROPHOSPHORANES CONTENANT LE LIGAND α AMINOACIDE
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Water and alcohol react with spirophosphoranes 1-3 to give respectively tetracoordinated phosphorus compounds with a P-H bond and phosphites; in all cases the α aminoacid is removed.Hexacoordinated entities are observed at low temperature during alcoholysis.
- Garrigues, Bernard,Munoz, Aurelio,Mulliez, Michel
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p. 183 - 188
(2007/10/02)
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- Selective formation of ethanol from methanol, hydrogen and carbon monoxide
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A process for the selective formation of ethanol which comprises contacting methanol, hydrogen and carbon monoxide with a catalyst system comprising cobalt acetylacetonate, a tertiary organo Group V A compound of the periodic Table, a first promoter comprising an iodine compound and a second promoter comprising a ruthenium compound.
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