- SYN TO ANTI ISOMERIZATION AND DEGRADATION OF PHOSPHINES OF THE 7-PHOSPHANORBORNENE SYSTEM BY ACTION OF METHANOL
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Syn-Substituted phosphines of the 7-phosphanorbornene system form unstable phosphorane adducts with methanol that either fragment by retro-McCormick cycloaddition or undergo polytopal rearrangement and loss of methanol to give the first example of anti phosphines.
- Mesch, Keith A.,Quin, Louis D.
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- Reactions of Ferrocenium Hexafluorophosphate with P?OR Nucleophiles Give Ring C?H Functionalization or Ring Replacement Products Depending on the Phosphorus Reagent
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Ferrocenium hexafluorophosphate reacts with different P?OR nucleophiles (PR3) in CH2Cl2 at room temperature to give either half-sandwich complexes [CpFe(PR3)3](PF6) (PR3=P(OMe)3, P(OEt)3, PhP(OMe)2) or ferrocenylphosphonium salts [CpFe(C5H4PR3)](PF6) (PR3=iPr2P(OMe), iPr2P(OEt)). Mixtures of both products are formed for some other nucleophiles (PR3=Ph2P(OMe), Ph2P(OEt), PhP(OiPr)2). The mechanism of the former reaction was established using DFT calculations. This reaction pathway is especially characteristic of π-acceptor nucleophiles, which is presumably explained by their ability to stabilize the 19e intermediates. The result of the reaction with tertiary phosphines, aminophosphines, and P?OR nucleophiles can be reliably predicted based on the values of the Tolman electronic parameter (below 2070 cm?1 – only ferrocenylphosphonium salt, in between 2073 cm?1 and 2080 cm?1 – only half-sandwich complex, and in the range from 2070 cm?1 to 2073 cm?1 – mixtures of both products).
- Chamkin, Aleksandr A.,Krivykh, Vasily V.,Kreindlin, Arkady Z.,Dolgushin, Fedor M.,Ustynyuk, Nikolai A.
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p. 1601 - 1610
(2021/04/16)
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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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- Efficient Synthesis of Phosphonamidates through One-Pot Sequential Reactions of Phosphonites with Iodine and Amines
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A one-pot sequential strategy to construct phosphonamidates has been developed by generating phosphonites in situ from arylmagnesium bromides and triethyl phosphite followed by treatment with iodine and amines. A variety of phosphonamidates were obtained with good to excellent yields at room temperature from easily available materials.
- Chen, Xunwei,Luo, Wenjun,Wang, Yanlin,Li, Zikang,Ma, Xiaorui,Peng, Ai-Yun
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p. 14474 - 14480
(2020/10/06)
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- Scalable Enantiomeric Separation of Dialkyl-Arylphosphine Oxides Based on Host–Guest Complexation with TADDOL-Derivatives, and their Recovery
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Several dialkyl-arylphosphine oxides were prepared, and the enantioseparation of the corresponding racemates was elaborated with host–guest complexation using TADDOL-derivatives. The crystallization conditions were optimized and two separate crystallization methods, one in organic solvent, and the other in water, were found to yield five examples of phosphine oxides with enantiomeric excess values higher than 94 %. A gram scale resolution was performed, and both enantiomers of the methyl-phenyl-propyl-phosphine oxide were separated with (R,R)- or (S,S)-spiro-TADDOL. The intermolecular interactions responsible for the enantiomeric recognition between the chiral host and guest molecules were investigated by single-crystal X-ray diffractional structural determinations. The similarities in the structural patterns of a few diastereomeric crystals were checked by powder X-ray diffraction, as well. Organic solvent nanofiltration (OSN) was used as a scalable technique for the decomposition of the corresponding phosphine oxide–spiro-TADDOL molecular complexes, and for the recovery of the phosphine oxide enantiomers and resolving agents.
- Bagi, Péter,Fogassy, Elemér,Herbay, Réka,Holczbauer, Tamás,Keglevich, Gy?rgy,Mátrav?lgyi, Béla,Madarász, János,Székely, Gy?rgy,Varga, Bence
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supporting information
(2020/03/23)
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- Preparation method for catalytically compounding benzyl phosphonate by using basic ionic liquid
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The invention belongs to the technical field of organic synthesis and relates to a preparation method for benzyl phosphonate as a key intermediate of an acyl phosphine oxide type photoinitiator. According to the method, benzene, phosphorus trichloride and alkyl alcohol are taken as main raw materials and are compounded into benzyl phosphonate through two-step reaction. The preparation method is characterized in that a target product is generated through the low-temperature reaction of the dichlorophenyl phosphine and alcohol under the condition of a gemini basic ionic liquid catalyst in the second step reaction, the reaction temperature is controlled within -10 DEG C to 10 DEG C, the dichlorophenyl phosphine is dropwise added and then the mixture reacts for 0.5-7 hours under a stirring condition after the temperature is increased to 30-50 DEG C. The preparation method has the advantages of low cost, simple and convenient after-treatment, high yield, and the like, and is suitable for industrial production.
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- Direct conversion of phosphonates to phosphine oxides: An improved synthetic route to phosphines including the first synthesis of methyl JohnPhos
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The synthesis of tertiary phosphine oxides from phosphonates was achieved reliably and in good to excellent yields using stoichiometric amounts of alkyl or aryl Grignard reagents and sodium trifluoromethanesulfonate (NaOTf). In the absence of the NaOTf additive, covalent coordination oligomers of magnesium and phosphorus species dominate the reaction, producing very low yields of phosphine oxide, but high conversions of the phosphonate starting material. Mechanistic studies revealed that a five-coordinate phosphorus species - not a phosphinate - is the reaction intermediate. A diverse array of phosphonates was converted to phosphine oxides using a variety of Grignard reagents for direct carbon-phosphorus functionalization. This new methodology especially simplifies the synthesis of dimethylphosphino (RPMe2)-type phosphines by using air-, water-, and silica-stable intermediates. To highlight this reaction, a new Buchwald-type ligand ([1,1′-biphenyl]-2-yldimethylphosphine, or methyl JohnPhos) and a classic bidentate phosphine, bis(diphenylphosphino)propane (dppp), were synthesized in excellent yields.
- Kendall, Alexander J.,Salazar, Chase A.,Martino, Patrick F.,Tyler, David R.
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supporting information
p. 6171 - 6178
(2015/02/19)
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- Simple unprecedented conversion of phosphine oxides and sulfides to phosphine boranes using sodium borohydride
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A variety of phosphine oxides and sulfides can be efficiently converted directly to the corresponding phosphine boranes using oxalyl chloride followed by sodium borohydride. Optically active P-stereogenic phosphine oxides can be converted stereospecifically to phosphine boranes with inversion of configuration by treatment with Meerwein's salt followed by sodium borohydride.
- Rajendran, Kamalraj V.,Gilheany, Declan G.
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supporting information; experimental part
p. 817 - 819
(2012/02/03)
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- Enantioselective preparation of P-chiral phosphine oxides
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A highly efficient chiral auxiliary-based strategy for the asymmetric synthesis of P-chiral phosphine oxides in >98:2 er has been developed. The methodology involves the highly stereoselective formation of P-chiral oxazolidinones that then undergo displacement with a variety of Grignard reagents to prepare the desired phosphine oxides.
- Adams, Harry,Collins, Rebecca C.,Jones, Simon,Warner, Christopher J. A.
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supporting information; experimental part
p. 6576 - 6579
(2012/01/15)
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- Synthesis of P-stereogenic phosphorus compounds. Asymmetric oxidation of phosphines under appel conditions
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Racemic phosphines are converted into enantioenriched phosphine oxides via a synthetically simple, but theoretically interesting, oxidation procedure in good enantiomeric excess (up to 80%) and excellent yields (>95%). These phosphine oxides can be oxidatively coupled to provide easy access to enantiopure DiPAMPO analogues. Particularly attractive aspects of this procedure are the operational simplicity and the low cost required to synthesize these high value compounds. Copyright
- Bergin, Enda,O'Connor, Cormac T.,Robinson, Shane B.,McGarrigle, Eoghan M.,O'Mahony, Colm P.,Gilheany, Declan G.
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p. 9566 - 9567
(2008/02/13)
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- Practical synthesis of chiral vinylphosphine oxides by direct nucleophilic substitution. Stereodivergent synthesis of aminophosphine ligands
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A practical synthesis of optically pure alkylphenylvinylphosphine oxides is described, utilizing a nucleophilic displacement at phosphorus to install the vinyl moiety. The products were used to prepare classes of P-stereogenic aminophosphine (PN) and aminohydroxyphosphine (PNO) ligands. Stereocontrol can be exerted at various stages of the synthesis, to provide specific combinations of chirality in the final product. The effect of the stereogenic phosphorus and match-mismatch of chiralities of PNO ligands were examined in the asymmetric ruthenium-catalyzed hydrogen transfer reduction of three aryl ketones.
- Oliana, Marco,King, Frank,Horton, Peter N.,Hursthouse,Hii, King Kuok
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p. 2472 - 2479
(2007/10/03)
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- Catalysis of the ethanolysis of aryl methyl phenyl phosphinate esters by alkali metal ions: Transition state structures for uncatalyzed and metal ion-catalyzed reactions
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This paper reports on a spectrophotometric kinetic study of the effects of the alkali metal ions Li+ and K+ on the ethanolysis of the aryl methyl phenyl phosphinate esters 3a-f in anhydrous ethanol at 25°C. Rate data obtained in the absence and presence of complexing agents afford the second-order rate constants for the reaction of free ethoxide (kEtO-) and metal ion-ethoxide ion pairs (kMOEt). The sequence k EtO- MOEt is established for all the substrates, contrary to the generally observed reactivity order in nucleophilic substitution processes. The quantities δGip, δGts and ΔGcat, which quantify the observed alkali metal ion effect in terms of transition state stabilization through chelation of the metal ion, give the order δGts > δGip for Li+ and K+. Hammett plots show significantly better correlation of rates with σ and σo substituent constants than with σ-, yielding moderately large Ρ(Ρo) values that are consistent with a stepwise mechanism in which formation of a pentacoordinate (phosphorane) intermediate is the rate-limiting step. The range of the values of the selectivity parameter, Ρn (= Ρ/Ρeq), 1.3 1.6, obtained for the uncatalyzed and alkali metal ion catalyzed reactions indicates that there is no significant perturbation of the transition state (TS) structure upon chelation of the metal ions. This finding is relevant to the mechanism of enzymatic phosphoryl transfer involving metal ion co-factors. The present results enable one to compare structural effects for nucleophilic reactions of several series of organophosphorus substrates. It is shown that the order of reactivity of the substrates: 4-nitrophenyl dimethyl phosphinate (2) > 3a > 4-nitrophenyl diphenyl phosphinate (1) is determined mainly by the steric effects of the alkyl/aryl substituents around the central P atom in the TS of the reaction. The Royal Society of Chemistry 2005.
- Onyido, Ikenna,Albright, Kendall,Buncel, Erwin
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p. 1468 - 1475
(2007/10/03)
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- Phosphinamides catalysts containing a stereogenic phosphorus atom for the asymmetric reduction of ketones by borane
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The effect of the configuration of the phosphorus atom in phosphinamide reduction catalysts has been studied through the preparation and use of a series of catalysts containing stereogenic phosphorus atoms of known configuration. The conclusion of this work is that a stereogenic centre at phosphorus can improve the selectivity of reductions using this catalyst, but is not sufficient in itself to generate the higher levels of selectivity which have been achieved with related catalysts. The X-ray crystallographic Structure of a key compound is also featured.
- Burns, Barry,Gamble, Mark P.,Simm, Athene R. C.,Studley, John R.,Alcock, Nathaniel W.,Wills, Martin
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- Phenylfluorophosphoranes: axial-equatorial fluorine exchange in RC6H4PF3H and intermolecular exchange in the PhPF2(H)OMe-MeOH-base system
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Activation parameters for axial-equatorial fluorine exchange in arylfluorophophoranes PC6H4PF3H, where R = o-CF3, m-CF3, m-CH3, were studied by the dynamic nmr technique. Δ G298(excit.) varied between 53 and 56 kJ mol-1.The synthesis of difluoromethoxyphenylphosphorane, PhPF2(H)OMe, from PhPF2 and MeOH is catalyzed by small amounts of Et3N, pyridine, PhPF3H, or HF.Rapid intermolecular ligand exchange occurs in PhPF2(H)OMe after addition of methanol and a base such as triethylamine or pyridine.Under these conditions, exchange of fluorine, hydrogen, and methoxy ligands occurs, as shown by 1H, 19F, and 31P nmr.From a line shape analysis of the 31P nmr spectrum, the rate of P-F cleavage was found to be first order (1.17 +/- 0.2) in Et3N concentration, with Δ G(excit.)298 = 50 kJ mol-1 and Δ S (excit.) = -67 J mol-1 deg-1.An equilibrium constant of 1.8 at 25 deg C was found for the reaction of PhPF2(H)OMe with PhPF2.
- Kruczynski, Leonard J.,Lemire, Alberta E.,Marat, Kirk,Janzen, Alexander F.
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p. 488 - 491
(2007/10/02)
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- LES PHOSPHORANES MONOCYCLIQUES A LIAISON PH DANS LES REACTIONS DE REDISTRIBUTION DE LIGANDS DES COMPOSES DU PHOSPHORE TRICOORDONNE
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The oxidative addition of alcohols and amines with 2-alkyl, 2-aryl, 1,3,2-dioxa, oxaza or diazaphospholanes, leads to a ring opening reaction and ligands exchange around the phosphorus atom by alcoholysis or aminolysis of P-O or P-N bonds.In nearly all cases, monocyclic phosphoranes with P-H bond have been detected in an intermediate step during the exchange of one tricoordinate form to another one.At last we have discussed the phorpholanyl ring stability. - Key words: 1,3,2-Dioxaphospholanes; 1,3,2-oxaza-phospholanes; 1,3,2-diazaphospholanes; Monocyclic phosphoranes with P-M bonds; phosphoranyl ring stability.
- Tangour, B.,Malavaud, C.,Boisdon, M. T.,Barrans, J.
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p. 189 - 196
(2007/10/02)
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- COMPOSES DU PHOSPHORE DICOORDONNE - ACTION DES ORGANOMAGNESIENS SUR LES DERIVES DU TRIAZAPHOSPHOLE-1,2,4,3: SYNTHESE DE DERIVES DE LA H-4 TRIAZAPHOSPHOLINE-1,2,4,3 ET MISE EN EVIDENCE DE L'EQUILIBRE DE SCHLENK
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2,5-disubstituted 1,2,4,3-triazaphospholes - dicoordinated phosphorus compounds - react with organomagnesium halide, in ether, to give the corresponding triazaphospholinyl magnesium halides.Their hydrolysis, alcoholysis or hydrogen abstraction from suitable solvents afford the corresponding triazaphospholines which are easily sulfured.By intervention of the Schlenk equilibrium in benzene, we obtain a mixture of the triazaphosphonyl magnesium halide and a complex of the triazaphosphole reagent with magnesium halide occurring in the solution.Some properties of these new triazaphospholines were investigated.
- Haddad, M.,M'Pondo, Th. N'Gando,Malavaud, C.,Lopez, L.,Barrans, J.
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p. 333 - 346
(2007/10/02)
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- PHOTOCHEMICAL REACTIONS OF PHOSPHAALKENES
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Photolysis of phosphaalkenes leads to an inversion of polarity of the phosphorus carbon double bond and to a cleavage into transient phosphinidene and carbene; unexpected alcoholysis of a PIII-C bond and the cycloaddition of a linear phosphaalkene on a diene are also reported.
- Meriem, Abdelkader,Majoral, Jean-Pierre,Revel, Monique,Navech, Jacques
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p. 1975 - 1978
(2007/10/02)
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- On Organophosphorus Compounds, XXII. 1,2-Diaryl-1,2-dibromodiphosphanes
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1,2-Diaryl-1,2-dibromodiphosphanes R(Br)P-P(Br)R 2 (R = C6H5; 4-XC6H4, X = CH3O, F, Cl) were prepared by dehalogenation of RPBr2 with magnesium in a one-batch procedure.While solid 2 presumably consists of only one diastereomer there exists an equilibrium between meso-2, rac-2 and their disproportionation products RPBr2 and (RP)5 in solutions of 2.The influence of temperature, R and solvent on this equilibrium was investigated. - The reaction products of the dissolved phenyl compound 2a correspond to a reaction of its disproportionation products PhPBr2 and (PhP)5, the former preferably reacting on nucleophilic substitution, the latter with electrophilic agents.Under heterogenous conditions diphosphanes Ph(R)P-P(R)Ph can be obtained from 2a and LiR.
- Hinke, Axel,Kuchen, Wilhelm
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p. 3003 - 3010
(2007/10/02)
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- Organphosphorus Compounds. XVIII. Synthesisi of 2-Phenyl-2,3-dihydro-1H-1,2-benzazaphosphole 2-Sulfide by Pyrolysis of (2-Aminobenzyl)phenyldithiophosphonic Acid
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Reaction of 2-phthalimidobenzyl bromide (12b) with the dialkyl phenylphosphonites (13a-c) afforded the corresponding alkyl phosphinates (14a-c) which upon hydrazinolysis yielded the respective (2-aminobenzyl)phenylphosphinates (16a-c).Reduction of the phosphinates (16a) or (16b) with lithium aluminium hydride gave (2-aminobenzyl)phenylphosphine (15), characterized by its conversion into crystalline 2,3-diphenyl-1,2,3,4-tetrahydro-1,3-benzazaphosphorine (18). (2-Aminobenzyl)phenylphosphine (15) was heated with sulfur in benzene under reflux for 30 min to give 80percent of (2-aminobenzyl)phenyldithiophosphinic acid (20) which when heated between 100-200 deg in vacuum underwent elimination of hydrogen sulfide to yield 2-phenyl-2,3-dihydro-1H-1,2-benzazaphosphole 2-sulfide (22a).Several other new phosphorus compounds are described.An attempt to prepare a 1H-1,2-benzazaphosphole derivative by photolysis of methyl benzylphosphonic azide (7) was unsuccessful.
- Collins, David J.,Drygala, Peter F.,Swan, John M.
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p. 2095 - 2110
(2007/10/02)
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- PHOSPHINYLALKANOYL PROLINES
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New phosphinylalkanoyl prolines which have the general formula STR1 wherein R 1 is lower alkyl, phenyl or phenyl-lower alkyl; R 2 is hydrogen, phenyl-lower alkyl or a metal ion; R 3 is hydrogen or lower alkyl;R. sub. 4 is hydrogen, lower alkyl, phenyl-lower alkyl or a metal ion; andN IS 0 OR 1,ARE USEFUL AS HYPOTENSIVE AGENTS.
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- Derivatives of cis-epoxy-1,2-propyl-phosphonic acid and drugs containing in particular as active ingredients derivatives of cis-epoxy-1,2-propylphosphonic acid in dextrorotatory form
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New asymmetrical derivatives of cis-epoxy-1,2-propylphosphonic acid, corresponding to the formula: STR1 in which: M(+) and M'(+), which are identical or different, are chosen from the hydrogen ion and the inorganic or organic cations, A is chosen from: The straight or branched alkyl and alkoxy radicals having 1 to 8 carbon atoms and being able to comprise at least one substitutent constituted by an epoxy bridge or chosen from the alkoxy radicals having 1 to 5 carbon atoms, alkoxycarbonyl whose alkyl radical comprises from 1 to 5 carbon atoms, amino, alkylamino, nitrile, The aryl, aralkyl, arylkoxy radicals which are substituted or not, Said products being useful particularly as drugs.
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- 6-Hydroxy (alkoxy) phenylthiomethylene di(organophosphorus) compounds and process for making same
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The invention relates to o-hydroxy(or alkyloxy)-phenythiomethylenedi(organophosphorus) compounds and to processes for making the same. The compounds have the general formula STR1 where L is H or R', R' is alkyl of 1 to 6 carbon atoms M is H, Cl or Br, X is Br, Cl, F, CF3, NO2, CN, CO2 R', SO2 R', or STR2 and R is phenyl, alkyl of 1 to 3 carbon atoms, or OR'. The compounds of the invention have utility as corrosion inhibitors, oil additives and flame retardants.
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- Hydroxyphenylthiophosphoranylidene organophosphorus compounds
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The present invention relates to a new hydroxyphenylthiophosphoranylidene organophoshorus compounds and to a process involving an unusual phenyl migration for their preparation. The general reaction for the preparation of the products of the present invention is set forth below: STR1 WHERE X is halogen (F, Cl, Br), NO2, CN, CO2 R', SO2 R', CF3 or STR2 R is phenyl, alkyl of 1 to 3 carbon atoms, or OR', and R' is alkyl of 1 to 6 carbon atoms. The compounds of the invention are useful as flame retardants, lubricating oil additives and as corrosion inhibitors.
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