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Tris(hydroxymethyl)phosphine oxide, (HOCH2)3PO (THPO), is recognized as an efficient flame-retardant polyol and a derivative of PH3 – an environment-friendly, halogen-free source for phosphorus compounds and polymers. Synthesis and industrial production of THPO are based on straightforward oxidation of tris(hydroxymethyl)phosphine, (HOCH2)3P (THP), or neutralized tetrakis(hydroxymethyl)phosphonium chloride (THPC), or sulfate (THPS), by air/O2 or H2O2. In alkaline aqueous media, THP is oxidized by water with liberation of H2. As an alcohol, THPO readily reacts with isocyanates, epoxides, aziridines, and carboxylic acid derivatives, and is widely used as crosslinker or chain-extender to produce flame-retardant polyurethanes, polyethers, polyesters, and composite materials. Similarly, with compounds containing E–Cl bonds (E = P, Si, and S), THPO forms a variety of flame-retardant P/E-compounds or polymers. Condensation of THPO with phenols proceeds via cleavage of a P–C bond of THPO and liberation of CH2O that leads to flame-retardant THPO-phenol resins. With functionalized alkyl halides, THPO forms tris(alkoxymethyl)phosphine oxide monomers containing, for example, pendant allyl, propargyl, or silane groups. Halogenation of THPO leads to tris(chloromethyl)phosphine oxide, (ClCH2)3PO, or tris(bromomethyl)phosphine oxide, (BrCH2)3PO, useful for syntheses of multifunctional organophosphorus compounds, for example, tris(aminomethyl)phosphine oxide, (NH2CH2)3PO, and phosphorus-containing podands. Similar to THPO, tris(hydroxymethyl)phosphine sulfide, (HOCH2)3PS, is used in preparation of flame-retardant components for polymers, and, in synthesis of asymmetric phosphorus compounds. [ABSTRACT FROM AUTHOR]

Visible light-mediated photocatalytic phosphorylation of α-bromostyrenes is described. The β-ketophosphine oxide derivatives were conveniently synthesized from α-bromostyrene derivatives, which are useful synthetic intermediates, using an inexpensive organic photocatalyst, Eosin Y. [ABSTRACT FROM AUTHOR]

Secondary phosphine oxides R2P(O)H are a relatively stable tautomeric form of secondary phosphinous acids R2P–OH that with imine/iminium species, or their donors, form compounds with a P(O)–Csp3–N linkage (the phospha-Mannich reaction). These can be referred to as (α-aminoalkyl)phosphine oxides, (α-phosphinoylalkyl)amines, or P(O),N-acetals. Compared to P–Csp3–N linkages of P,N-acetals, products of phospha-Mannich reactions involving secondary phosphines R2PH, the P(O)–Csp3–N linkage is significantly more stable that allows for many examples of α-functionalized P(O),N-acetals and α-phosphinoylated N-heterocycles, whereas such examples for P,N-acetals are rare. Trivalent derivatives of phosphinous acids such as halides R2P–Hal, esters R2P–OR' (phosphinites), amides R2P–NR'2 (aminophosphines), and phosphides R2P–PR'2 (biphosphines) also participate in Mannich-type reactions with mechanisms depending on the reactants. The phosphinous halides and esters react with (α-alkoxyalkyl)amines (N,O-acetals) and (α-haloalkyl)amines (N,Hal-acetals), respectively, via Arbuzov-type intermediates that are rearranged into P(O),N-acetals and alkyl halides (Arbuzov rearrangement). Furthermore, unlike phospha-Mannich reactions involving phosphines, secondary phosphine oxides and P(O),N-acetals are less sensitive to oxidation, and imines/iminium species can be generated not only under conventional Mannich conditions, i.e., from N,E-acetals (E = OH, O, N, halogen, etc.), but also, for example, by oxidation of α-C-atom of amines, or by oxidation of alcohols to aldehydes that than form imines/iminium species with amines. [ABSTRACT FROM AUTHOR]

One pot sequential reactions of silica gel with tetrachlorosilane/triethylamine mixture and after with the conical upper rim tetraphosphorylated tetrahydroxy(thia)calixarenes yielded porous organo-inorganic sorbents modified by spatially ordered phosphonate, phosphinate or phosphine oxide groups capable of co-operative binding of metal cations. The grafting improves efficacy of europium(III) sorption by the silica gels. DFT calculations of the calixarene-Eu3+ complexes predict a calixarene flattened cone conformation with the coordination of Eu3+ cation to three of four P = O oxygen atoms and one of the aromatic systems. Adding three water molecules excludes completely cation–π interactions. [ABSTRACT FROM AUTHOR]

The reaction of diphenylphosphine oxide successively with two aryne precursors was investigated in order to access valuable functionalizable nonsymmetrical dibenzophospholes. The reactions proved sensitive to substituents of aryne precursors able to coordinate the incoming lithiated nucleophile. [ABSTRACT FROM AUTHOR]

Sequential treatment of silica gel with tetrachlorosilane and cone-shaped tetraphosphorylated tetrahydroxy(thia)calixarenes yielded porous organo-inorganic sorbents, the surface of which is covered by spatially ordered phosphonate, phosphinate and phosphine oxide groups capable of co-operative binding of metal cations. Sorption of europium(III) by the modified silica gels was studied. [ABSTRACT FROM AUTHOR]

The phosphorus–oxygen bond formation reactions often observed for the sterically crowded triarylphosphines and their radical cations were studied by DFT calculation. The oxidations of the trimethyl-, triphenyl-, and trimesityl-phosphines to the corresponding phosphine oxides with peroxides are shown to proceed through the SN2 like transition states and the overall influence of the steric hindrance on the activation energy is limited. The reaction of the radical cation of tris(2,4,6-triisopropylphenyl)phosphine with oxygen to give the heterocyclic phosphonium cation is modeled by employing (2,6-diisopropylphenyl)diphenylphosphine and the comparison of the intermediates suggests highly exergonic nature of the reaction. [ABSTRACT FROM AUTHOR]

A tetraalkylhydrophosphorane having three methylene groups instead of three equatorial oxygen atoms of a 1-hydro-5-carbaphosphatrane was synthesized by the reaction of the corresponding phosphonium salt with LiAlH4. A tetraalkylchloro- phosphorane was obtained from the phosphonium salt. Their X-ray crystallographic analyses showed that they have nearly ideal trigonal bipyramidal structures. Their bond lengths and angles as well as apical coupling constants showed that they have usual apicophilic arrangement. The tetraalkylhydrophosphorane gave two phosphine oxides, one of which was formed via homolytic bond cleavage of P-methine carbon bonds under daylight. Another phosphine oxide was estimated to be its isomer formed via the P-benzyl bond cleavage. The reaction of the chlorophosphorane with Me3Al afforded the corresponding pentaalkylphosphorane with the methyl group. [ABSTRACT FROM AUTHOR]

In this conference proceeding, our newest results on the two-step esterification of phenylphosphonic acid (1/A1 and A2), on the hydrolysis of arylphosphonates (1/B) and other related compounds, on the Ni-catalyzed Hirao P–C coupling reaction (2/A), on the Kabachnik–Fields reaction of carboxylic amides (2/B), and on the reactions of α-hydroxyphosphonates, such as their phosphorylation (3/A) and rearrangement reactions (3/B) were summarized. [ABSTRACT FROM AUTHOR]

A facile method for the synthesis of β-functionalized ethyldiphenylphosphine oxides is developed based on readily available 2-phenoxyethyldiphenylphosphine oxide used as an equivalent of diphenylvinylphosphine oxide in the reactions of addition of different PH- and NH-nucleophiles in DMSO in the presence of KOH. The transformations of labile phosphine oxides of a general formula Ph2P(O)CH2CH2OR, where R = Ph, H, or Ph2P(O)CH = CH2, in aq.KOH/DMSO and solid KOH/DMSO systems are explored in the absence of nucleophilic reagents. [ABSTRACT FROM AUTHOR]

A simple one-pot method for the synthesis of 2-aminoethyldiphenylphosphine oxides is developed based on readily available diphenyl(2-phenoxyethyl)phosphine oxide and amines of different types under phase transfer catalysis conditions using anhydrous cesium carbonate as a base in acetonitrile or DMSO. [ABSTRACT FROM AUTHOR]

This study details the oxidation of α-hydroxy(2,4,6-trimethylbenzyl)diphenylphosphine oxide (α-HDPO) to diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) by choosing the proper MnO2 as oxidant. In addition, the equilibrium of α-HDPO and 2,4,6-trimethylbenzaldehyde (MesCHO) was discussed. [ABSTRACT FROM AUTHOR]

A novel tertiary phosphine oxide containing two quinaldinyl substituents has been synthesized according to adapted literature procedures. Its coordination properties toward Cu(I) and Ag(I) were investigated and the resulting complexes were analyzed by single crystal X-ray diffraction. Multinuclear complexes are formed, wherein the ligand is bridging across two metal centers. Though for the silver complex, no argentophilic interactions are present. The copper complex was characterized further by multinuclear NMR spectroscopy at variable temperatures. [ABSTRACT FROM AUTHOR]

This chapter discusses the reactions of 4-phosphorylated 5-hydroxypenta-2,3-dienoates with protected or unprotected hydroxy group involving 5-endo-trig cyclizations. Reactions with electrophiles produce mixtures of the 2,5-dihydro-1,2-oxaphosphole-5-carboxylates and the 5-phosphoryl-furan-2(5H)-ones by competitive electrophilic cyclization due to the neighboring phosphonate (phosphine oxide) and the carboxylate groups participation. 4-Phosphorylated 5-hydroxypenta-2,3-dienoates were smoothly converted into the corresponding 4-phosphoryl-2,5-dihydrofuran-2-carboxylates by using 5 mol% of a silver salt as a catalyst in the 5-endo-trig cycloisomerization reaction. [ABSTRACT FROM AUTHOR]

Racemic acyclic phosphine oxides were separated into their enantiomers applying classical resolution methods based on complexation with chiral host molecules. The preparation of chloro-3-phospholenium chlorides was elaborated by the reaction of 3-phospholene oxides with oxalyl chloride. The cyclic chlorophosphonium salts were key intermediates, as they could be converted to the corresponding 3-phospholene boranes. Moreover, these reactive intermediates could be reacted with chiral alcohols, which enabled us to develop a dynamic resolution of 3-phospholene oxides based on the formation of covalent diastereomeric intermediates. P-Stereogenic phosphine oxide pre-catalysts showed promising enantioselectivity values in a catalytic Wittig-reaction. [ABSTRACT FROM AUTHOR]

Phosphinic- and phosphonic esters, as well as phosphine oxides can be easily obtained by P–C coupling reactions of aryl- and vinyl halides with dialkyl phosphites, H-phosphinates and secondary phosphine oxides in the presence of mostly Pd catalysts. The use of the microwave (MW) technique allows the realization of the Hirao reaction more efficiently, economically and environmentally-friendly. [ABSTRACT FROM AUTHOR]

We propose a new, potentially widely-applicable, Umpolung approach for the synthesis of quaternary phosphonium salts R3PR1 X (X = Cl, Br) from phosphine oxides R3PO. The new organic group R1 is introduced via nucleophilic attack on an intermediate halophosphonium salt using a Grignard reagent R1MgX and replaces the traditional phosphine quaternization approach. Consequently, the new method does not suffer from the limited availability of many parent phosphines and is much faster than standard quaternization. [ABSTRACT FROM AUTHOR]

Aminophosphine oxides and bis(phosphinoylmethyl)amines were synthesized by the microwave (MW)-assisted Kabachnik-Fields reaction of primary amines, paraformaldehyde and secondary phosphine oxides. The bisphosphines obtained after deoxygenation of the bis(phosphinoymethyl)amine derivatives were utilized in the synthesis of cyclic transition metal complexes. [ABSTRACT FROM AUTHOR]

A polystyrene-supported phosphine oxide-catalysed Beckmann rearrangement of ketoximes in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) has been developed. Good substrate compatibility, mild reaction conditions, good yields as well as the reusability of the catalyst/solvent made this procedure more environmentally benign. [ABSTRACT FROM AUTHOR]

The present paper discusses the coinage metal-catalyzed cycloisomerization reaction of phosphorylated 3-(α- or β-hydroxyalkyl)allenes. 3-(α- or β-Hydroxyalkyl)-allenylphosphonates and -allenyl phosphine oxides were smoothly converted into the 2-phosphoryl-2,5-dihydrofurans or 2-phosphoryl-5,6-dihydro-2Н-pyrans by using 5 mol % of coinage metal salts as catalyst in 5-endo-trig or 6-endo-trig cycloisomerization, respectively. Experimental conditions such as the type of the solvent, the reaction temperature, the mol % and the type of the catalyst and its influence on the yields and the reaction time of the cycloisomerization reaction of the phosphorylated 3-(α- or β-hydroxyalkyl)allenes were optimized. [ABSTRACT FROM AUTHOR]

The present paper discusses the electrophilic cyclization and addition reactions of 3-(α- or β-hydroxyalkyl)-allenylphosphonates and phosphine oxides. Treatment of 3-(α- or β-hydroxy-alkyl)-allenylphosphonates with electrophiles takes place with 5-endo-trig cyclization and gives 2-methoxy-2,5-dihydro-1,2-oxaphosphole 2-oxides as a result of the neighboring phosphonate group participation in the electrophilic cyclization. On the other hand, 3-(α- or β-hydroxyalkyl)-alk-(1E)-en-1-yl phosphine oxides were prepared by chemo-, regio-, and stereoselective electrophilic addition to the C2-C3-double bond in the 3-(α- or β-hydroxyalkyl)-alka-1,2-dienyl phosphine oxides and subsequent attack of the external nucleophile (halide anion). The paper proposes a possible mechanism that involves electrophilic cyclization and addition reactions of the phosphorylated (α- or β-hydroxyalkyl)allenes. [ABSTRACT FROM AUTHOR]

In this paper, we describe convenient methods for functionally active phenol addition reaction of allenylphosphonates/allenyl phosphine oxides. These reactions lead to either vinyl or allylphosphonates. In the reaction α-aryl allenylphosphonates with 2-iodophenol in the presence of Pd nanoparticles [Pd-PVP] isomeric vinylphosphonates are preferentially obtained. A novel cyclization reaction of 2-iodo-t-butylbenzaldimine with and allenylphosphine oxide that leads to an isoquinoline is also discovered; the product is characterized by single crystal X-ray structure determination. [ABSTRACT FROM PUBLISHER]

An efficient catalyst-free microwave (MW)-assisted method was elaborated for the batch and continuous flow synthesis of N-alkyl-isoindolinone phosphonates by the three-component reaction of 2-formylbenzoic acid, primary amines and various dialkyl phosphites. The reaction was also extended to various secondary phosphine oxides and primary amines, as well. In order to obtain more information about the condensation, the reaction mechanism was also studied by in situ FT-IR spectroscopy. [ABSTRACT FROM AUTHOR]

In this article, we describe some of our results on the reactions of allenylphosphonates/allenyl phosphine oxides and allenyl diazaphosphole oxides, primarily cycloaddition and cyclization reactions. Depending on the substituents, both the α,β and β,γ -cycloaddition products have been observed. A novel cyclization reaction of a functionalized allenylphosphine oxide with diethylamine leading to 3-diethylamino-4-diphenylphosphinoyl-1-naphthol is reported. Representative compounds have been characterized by X-ray crystallography. [ABSTRACT FROM PUBLISHER]

A facile two-step synthesis of bisphosphine monoxides (BPMOs, with both the phosphine and phosphine oxide moieties within one molecule) from readily available Morita–Baylis–Hillman (MBH) carbonates was realized. Under the catalysis of DABCO, the MBH carbonates undergo allylic phosphorylation reaction with diphenylphosphine oxide or diethyl phosphonate to give monophosphine oxides bearing an activated alkene moiety; subsequent base-catalyzed hydrophosphination of the prepared monophosphine oxide with HPPh2readily affords the BPMOs. [ABSTRACT FROM AUTHOR]

The reactions of carbamoylmethylphosphonates (CMP) and carbamoylmethylphosphine oxides (CMPO) with mercuric nitrate typically result in deprotonation of the methylene carbon atom spanning the phosphoryl and the amide carbonyl groups of the bifunctional ligand with concomitant formation of [Hg(L)](NO3) compounds containing a stable mercury-carbon σ bond. The resulting organometallic compounds form dimers [Hg(L)(NO3)]2via bidentate interactions between the phosphoryl oxygen atom and carbonyl oxygen atom in one [Hg(L)]+unit and the Hg(II) ion in the second [Hg(L)]+unit. Additional examples of this general reactivity/structure pattern are reported herein. In contrast, in Hg(II) complexes of two CMPO derivatives, in which the amide N-atom is functionalized with a 2-methylpyridine group, the trifunctional phosphine oxides are observed to behave as neutral ligands forming complexes (L′)Hg (NO3)2. [ABSTRACT FROM AUTHOR]

The deoxygenation of different phosphine oxides is an important issue. In this minireview, the reduction of mainly cyclic phosphine oxides and triaryl derivatives is surveyed using different silanes, such as trichlorosilane, phenylsilane, tetramethyldisiloxane (TMDS) and polymethylhydrosiloxane (PMHS). The best solution is the catalyst-free microwave (MW)-assisted variation in the absence of any solvent. [ABSTRACT FROM AUTHOR]

3- and 4-Methylstyrenes react with red phosphorus in the superbase system KOH/DMSO (110 °C, 2 h) to afford tertiary phosphine oxides in 20–25% total yield. Under microwave irradiation (600 W) this reaction proceeds for 5 min giving in the case of 2-, 3-, and 4-methylstyrenes mixtures of tris[2-(methylphenyl)ethyl]phosphines and their oxides. Subsequent treatment of these products with H2O2(acetone/H2O, r.t., 5 min) allowed the phosphine oxides to be isolated in 45–68% yields. 2,4,6-Trimethylstyrene reacts with red phosphorus (KOH/DMSO 600 W, 5 min) in a similar manner to furnish tris[2-(2,4,6-trimethylphenyl)ethyl]-phosphine oxide (40% yield) along with 2-(2,4,6-trimethylphenyl)ethylphosphinic acid (21% yield). [ABSTRACT FROM PUBLISHER]

A novel sterically crowded triarylphosphine, [4-methyl-2,6-bis(2-methylphenyl)phenyl]bis(2,4,6-triisopropylphenyl)phosphine (1), was synthesized by the reaction of 4-methyl-2,6-bis(2-methylphenyl)phenylcopper(I) with chlorobis(2,4,6-triisopropylphenyl)phosphine. Triarylphosphine1exhibits a low inversion barrier, a reversible oxidation at low potential, and a UV absorption in long wavelength typical of sterically crowded triarylphosphines. The mCPBA oxidation of1gave the corresponding phosphine oxide of more crowded and rigid structure. [ABSTRACT FROM PUBLISHER]

P-C coupling reactions of a variety of >P(O)H species with aryl bromides were found to take place under P-ligand-free microwave conditions. [ABSTRACT FROM PUBLISHER]

After a brief overview of the current development of carbeniophosphine ligands for applications in catalysis, in particular of imidazoliophosphines, a focus is given on the reference class of moderately flexible benzo-,diimidazolo-2,3,4,5,6,7-tris-annelated 3,6-diazaphosphepine derivatives with various exocyclic P–R substituents. The cases R = NMe2, NiPr2are addressed by comparison to the known cases R = Ph,tBu. After selective N,N′-dimethylation of the imidazole nitrogen atoms with MeOTf, further P-oxidation of the resulting dication withm-CPBA is shown to occur readily for R = NiPr2, as previously reported for R =tBu. In contrast, the same oxidative treatment of a parent neutral P-aminophosphepine is found to afford acis/transstereoisomeric mixture of the P-oxide. On the basis of line shape analyses of1H and31P NMR spectra between 313 and 373 K, the free enthalpy of activation of the stereo-conversion process is shown to be ca 17 kcal/mol. ROESY1H NMR experiments show that the major isomer exhibits acisorientation of the NiPr2group and the phenylene bridge. The corresponding boat conformation of the diazaphosphepine ring is confirmed by X-ray crystallography. As in the R =tBu series, the same boat conformation is observed in the crystal state of the dicationic oxide and neutral and dicationic P(III) parents. [ABSTRACT FROM PUBLISHER]

Novel polydentate neutral organophosphorus ligands containing two diphenyl-(diethylcarbamoyl-methyl)phosphine oxide moieties fixed on the arene platform via methylene-1,2,3-triazole linkers (Ar-CMPO) were synthesized by the method of click chemistry and studied as an extractant for Pd(II), U(VI), Th(IV), and lanthanides(III) ions from HNO3solutions. [ABSTRACT FROM PUBLISHER]

New 1,2-alkadienylphosphonates and diphenyl(1,2-alkadien-1-yl)phosphine oxides were synthesized by a convenient and efficient method. These compounds are useful as intermediates in the preparation of 2-(diethylphosphoryl)-3-(3-phenyl-4,5-dihydroisoxazol-5-yl)-2H-azirines, 2-(diethylphosphoryl)-3-vinyl-2H-azirines and diphenyl(3-isopropenyl-2H-azirin-2-yl)phosphine oxides. [ABSTRACT FROM PUBLISHER]

Resolution methods involving the formation of diastereomeric complexes were developed for the separation of cyclic P-stereogenic phosphine oxides and phosphinates. These resolution methods are of more general value, as they can be applied also for the enantioseparation of acyclic phosphine oxides. 5- and 6-Membered cyclic phosphine oxides were deoxygenated and then converted to platinum complexes which can be applied as catalysts in enantioselective hydroformylation. [ABSTRACT FROM PUBLISHER]

2-Hydroxymethylphenylphosphine oxides undergo partial racemization in the reaction with mesyl anhydride or mesyl chloride. A possible mechanism is discussed. [ABSTRACT FROM PUBLISHER]

The extraction properties of a series of carbamoylmethylphosphine oxides and β-aminophosphine oxides with lanthanide metal ions is presented. Tris[bis(2-diphenyl- phosphorylethyl)-aminoethyl]amine is shown to be highly effective for extraction of Re(VII). [ABSTRACT FROM PUBLISHER]

The Horner-Wittig reaction between diphenyl(2-phenylpropyl)phosphine oxide and 1-naphtaldehyde affords an equal mixture of thecisandtransisomers even though the formation of the initial adduct is selective. [ABSTRACT FROM PUBLISHER]

A simple two-step route to a series of carboxylic acid functionalized ditertiary phosphine oxides is described, including the X-ray crystal structures of three representative examples namely {Ph2P(O)CH2}2N(CH2)nCO2H (n= 3−5). Strong intermolecular O−H···O H-bonding is observed in all cases leading to distinct packing arrangements. [ABSTRACT FROM PUBLISHER]

Phosphine, generated from elemental phosphorus in the system KOH-toluene-H 2 O, reacts with vinyl sulfides under free radical conditions (AIBN, dioxane, 65–70°C, atmospheric pressure) to form regiospecifically tris[2-(organylthio)ethyl]phosphines, which are readily oxidized in air to corresponding tris[2-(organylthio)ethyl]phosphine oxides. [ABSTRACT FROM AUTHOR]

The reaction of iodosylbenzene with >P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O)< type. On the other hand if the reaction is performed in alcohol as a solvent in the presence of sodium alcoholate >P(O)OR ester is the major product. [ABSTRACT FROM AUTHOR]

A new two-step method for obtaining of phosphonium salts from phosphine oxides was developed. The method includes a cyclization of the dialkyl-2-(2-hydroxy-5-chlorophenyl)-2-phenylethenylphosphine oxides caused by sulfinyl chloride followed by the ring opening under the action of Grignard reagent. [ABSTRACT FROM PUBLISHER]

The resolution methods previously developed for the enantioseparation of heterocyclic phosphine oxides were extended to dialkyl-aryl-, diaryl-alkyl- and triarylphosphine oxides. The resolution of the phosphine oxides were elaborated with TADDOL-derivatives or with the acidic Ca2+-salts of the (R,R)-O,O'-dibenzoyl- and (R,R)-O,O'-di-p-toluoyl-tartaric acid. The main parameters influencing the efficiency of the resolution procedures were also optimized. Moreover, a correlation was found between the efficiency of the resolution and molecular structure. In a few instances, the purification and the racemization possibilities of the enantiomeric mixtures were also investigated. [ABSTRACT FROM AUTHOR]

H-phosphonates, H-phosphinates and secondary phosphine oxides (SPO) are essential compounds for the synthesis of pharmaceuticals, herbicides, pesticides, and phosphine ligands. Notably, prototropic tautomerism and substituent effects play an important role in the reactivity of the above compounds.[1] The main goal of our research was to study the tautomerism of symmetrical and asymmetrical phosphinic acids, by the means of computational investigation, applying several DFT and ab initio methods. We have investigated the effect of substituents, implicit solvents and also multiple kinetic pathways were elucidated for the possible tautomerization mechanism, including intramolecular, and various intermolecular routes. [ABSTRACT FROM AUTHOR]

New calix[4]arenes functionalized by Alk2P(O)CH2 and N-methylimidazolium groups at the opposite rims of the macrocyclic skeleton have been synthesized and characterized. Their extraction properties towards of Eu3+ and Am3+ in ionic liquid were investigated. [ABSTRACT FROM AUTHOR]

A 1,3-oxaphosphorinan, the product of a 1:1 reaction between cinnamaldehyde and (HOCH2)3P, interacts with a second mole of cinnamaldehyde to afford in MeOH an unsymmetrical phosphine oxide as the final product. [ABSTRACT FROM PUBLISHER]

The preparation of 3-phospholene boranes and optically active 3-phospholene oxides was elaborated via the corresponding cyclic chloro-phosphonium salt intermediates. The 3-phospholene oxides were reacted with oxalyl chloride to afford the corresponding chloro-phosphonium salts, which were reacted with LiBH4to afford 3-phospholene boranes. This procedure is a practical one-pot method for the deoxygenation and borane complex formation of 3-phospholene oxides without using silanes. It was shown that 3-chlorophospholenium salts can be reacted with chiral alcohols to give diastereomerically enriched cyclic alkoxy-phospholium salt intermediates, which were converted to enantiomerically enriched 3-phospholene oxides by Arbuzov collapse. [ABSTRACT FROM PUBLISHER]

The deoxygenation of phosphine oxides was studied on a series of model reactions using an aralkylsilane, arylsilanes, diarylsilanes, a disiloxane, a polysiloxane, and a disilane under solvent-free, thermal, or microwave-assisted conditions. The deoxygenations were optimized, and the reactivity of the silanes was evaluated. User-friendly accomplishments were elaborated. [ABSTRACT FROM PUBLISHER]

Electrochemical oxidative CH/PH functionalization reaction between diphenylphosphine oxide and diphenylacetylene has been performed. The yield of target cyclisation product was obtained with 76% yield after 4F of electricity was passed through the reaction mixture at 1.0 V (vs. Ag/AgCl). [ABSTRACT FROM PUBLISHER]

One-pot procedures were developed for the synthesis of lipophilic bisphosphorylated amines with high yields from the system dialkylphosphite-formaldehyde-amine on the first step and dihexyl- or di-p-tolylphosphine oxide, formaldehyde, and corresponding amine on the second step. [ABSTRACT FROM PUBLISHER]