- Catalytic Cleavage of Unactivated C(aryl)-P Bonds by Chromium
-
We describe here the coupling to transform aryl phosphine derivatives by the cleavage of unactivated C(aryl)-P bonds with chromium catalysis, allowing us to achieve the reaction with alkyl bromides and arylmagnesium reagents under mild conditions. Mechani
- Ling, Liang,Luo, Meiming,Tang, Jinghua,Yuan, Shuqing,Zeng, Xiaoming
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p. 1581 - 1586
(2022/03/14)
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- Reductive conversion of phosphoryl P(O) compounds to trivalent organophosphines R3P
-
By introducing trimethylsilyl chloride (TMSCl), the pentavalent phosphoryl P(V) compounds such as triphenylphosphine oxides, secondary phosphine oxides etc., were readily converted to the corresponding R2P(OTMS) intermediates, that can further react efficiently with an electrophile R'X or with a nucleophile R'Li to produce the corresponding trivalent phosphines R2PR’. Chiral phosphines could also be obtained stereospecifically by this strategy.
- Zhang, Jian-Qiu,Han, Li-Biao
-
-
- Ready Approach to Organophosphines from ArCl via Selective Cleavage of C-P Bonds by Sodium
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The preparation, application, and reaction mechanism of sodium phosphide R2PNa and other alkali metal phosphides R2PM (M = Li and K) have been studied. R2PNa could be prepared, accurately and selectively, via the reactions of SD (sodium finely dispersed in mineral oil) with phosphinites R2POR′ and chlorophosphines R2PCl. R2PNa could also be prepared from triarylphosphines and diarylphosphines via the selective cleavage of C-P bonds. Na was superior to Li and K for these reactions. R2PNa reacted with a variety of ArCl to efficiently produce R2PAr. ArCl is superior to ArBr and ArI since they only gave low yields of the products. In addition, Ph2PNa is superior to Ph2PLi and Ph2PK since Ph2PLi did not produce the coupling product with PhCl, while Ph2PK only gave a low yield of the product. An electron-withdrawing group on the benzene ring of ArCl greatly accelerated the reactions with R2PNa, while an alkyl group reduced the reactivity. Vinyl chloride and alkyl chlorides RCl also reacted efficiently. While t-BuCl did not produce the corresponding product, admantyl halides could give the corresponding phosphine in high yields. A wide range of phosphines were prepared by this method from the corresponding chlorides. Unsymmetric phosphines could also be conveniently generated in one pot starting from Ph3P. Chiral phosphines were also obtained in good yields from the reactions of menthyl chlorides with R2PNa. Possible mechanistic pathways were given for the reductive cleavage of R3P by sodium generating R2PNa and the substitution reactions of R2PNa with ArCl generating R2PAr.
- Ye, Jingjing,Zhang, Jian-Qiu,Saga, Yuta,Onozawa, Shunya,Kobayashi, Shu,Sato, Kazuhiko,Fukaya, Norihisa,Han, Li-Biao
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p. 2682 - 2694
(2020/07/30)
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- Palladium-catalyzed C(sp3)–P(III) bond formation reaction with acylphosphines as phosphorus source
-
Palladium-catalyzed C(sp3)–P(III) bond formation reaction for alkyl substituted phosphines preparation was developed. In this reaction, various alkyl bromides and limited alkyl chlorides reacted with acylphosphine under relative mild and easily accessible condition, and differential phosphines were afforded in good yields. This reaction made up the application of palladium catalysis in C(sp3)–P(III) bond formation, and indicated a practical application of acylphosphine as a phosphination reagent.
- Zhang, Mengyue,Ma, Zhichao,Du, Hongguang,Wang, Zhiqian
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-
- Direct and Scalable Electroreduction of Triphenylphosphine Oxide to Triphenylphosphine
-
The direct and scalable electroreduction of triphenylphosphine oxide (TPPO)-the stoichiometric byproduct of some of the most common synthetic organic reactions-to triphenylphosphine (TPP) remains an unmet challenge that would dramatically reduce the cost and waste associated with performing desirable reactions that are mediated by TPP on a large scale. This report details an electrochemical methodology for the single-step reduction of TPPO to TPP using an aluminum anode in combination with a supporting electrolyte that continuously regenerates a Lewis acid from the products of anodic oxidation. The resulting Lewis acid activates TPPO for reduction at mild potentials and promotes P-O over P-C bond cleavage to selectively form TPP over other byproducts. Finally, this robust methodology is applied to (i) the reduction of synthetically useful classes of phosphine oxides, (ii) the one-pot recycling of TPPO generated from a Wittig reaction, and (iii) the gram-scale reduction of TPPO at high concentration (1 M) with continuous product extraction and in flow at high current density.
- Manabe, Shuhei,Sevov, Christo S.,Wong, Curt M.
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p. 3024 - 3031
(2020/03/10)
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- Versatile Visible-Light-Driven Synthesis of Asymmetrical Phosphines and Phosphonium Salts
-
Asymmetrically substituted tertiary phosphines and quaternary phosphonium salts are used extensively in applications throughout industry and academia. Despite their significance, classical methods to synthesize such compounds often demand either harsh reaction conditions, prefunctionalization of starting materials, highly sensitive organometallic reagents, or expensive transition-metal catalysts. Mild, practical methods thus remain elusive, despite being of great current interest. Herein, we describe a visible-light-driven method to form these products from secondary and primary phosphines. Using an inexpensive organic photocatalyst and blue-light irradiation, arylphosphines can be both alkylated and arylated using commercially available organohalides. In addition, the same organocatalyst can be used to transform white phosphorus (P4) directly into symmetrical aryl phosphines and phosphonium salts in a single reaction step, which has previously only been possible using precious metal catalysis.
- Arockiam, Percia Beatrice,Lennert, Ulrich,Graf, Christina,Rothfelder, Robin,Scott, Daniel J.,Fischer, Tillmann G.,Zeitler, Kirsten,Wolf, Robert
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supporting information
p. 16374 - 16382
(2020/11/03)
-
- Selective C-P(O) Bond Cleavage of Organophosphine Oxides by Sodium
-
Sodium exhibits better efficacy and selectivity than Li and K for converting Ph3P(O) to Ph2P(OM). The destiny of PhNa co-generated is disclosed. A series of alkyl halides R4X and aryl halides ArX all react with Ph2P(ONa) to produce the corresponding phosphine oxides in good to excellent yields.
- Zhang, Jian-Qiu,Ikawa, Eiichi,Fujino, Hiroyoshi,Naganawa, Yuki,Nakajima, Yumiko,Han, Li-Biao
-
supporting information
p. 14166 - 14173
(2020/11/13)
-
- Mitsunobu Reaction Using Basic Amines as Pronucleophiles
-
A novel protocol for extending the scope of the Mitsunobu reaction to include amine nucleophiles to form C-N bonds through the utilization of N-heterocyclic phosphine-butane (NHP-butane) has been developed. Both aliphatic alcohols and benzyl alcohols are suitable substrates for C-N bond construction. Various acidic nucleophiles such as benzoic acids, phenols, thiophenol, and secondary sulfonamide also provide the desired products of esters, ethers, thioether, and tertiary sulfonamide with 43-93% yields. Importantly, C-N bond-containing pharmaceuticals, Piribedil and Cinnarizine, have been synthesized in one step from the commercial amines under this Mitsunobu reaction system.
- Huang, Hai,Kang, Jun Yong
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p. 6604 - 6614
(2017/07/15)
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- Alkyl diphenyl phosphine and preparing alkyl diphenyl phosphine payment proportional to production alkyl benzene
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The invention discloses alkyl diphenylphosphine and a method for preparing alkyl diphenylphosphine with co-production of alkylbenzene. The structural formula of alkyl diphenylphosphine is shown in a formula I. The method comprises: adding triphenylphosphine and metal lithium into an organic solvent for reaction for 3-6 hours at room temperature; and cooling the reaction system to 0-10 DEG C, adding halogenated straight-chain alkane for insulating reaction, then raising the temperature of the system to 30-80 DEG C, keeping the temperature to react for 1-3 hours, removing the organic solvent and reducing the pressure and distilling to separately obtain alkyl diphenylphosphine and alkylbenzene. According to the alkyl diphenylphosphine disclosed by the invention, alkyl is directly bonded with P, so that the alkyl diphenylphosphine can be dissolved in most solvents and can be used as a ligand for homogeneous catalysts. By virtue of the method disclosed by the invention, high value straight-chain alkylbenzene is co-produced while straight-chain alkyl diphenylphosphine is prepared by way of a one-pot process. Use of chloro-tert-butane which is relatively high in price and waste of the metal lithium are avoided. The method is simple to operate, efficient, low in energy consumption, low in cost and suitable for large-scaled industrial production.
- -
-
Paragraph 0046; 0048-0052
(2017/08/25)
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- Aryl group - A leaving group in arylphosphine oxides
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The treatment of triphenylphosphine oxide with organometallic reagents leads to the substitution of up to three phenyl substituents with the incoming carbon nucleophile. The replacement of the phenyl/aryl group in tertiary diarylalkylphosphine oxides or even aryldialkylphosphine oxides was also observed. Naphthyl-substituted phosphine oxides undergo Michael-type addition at the naphthyl group when treated with organolithium reagent.
- Stankevi?, Marek,Pisklak, Jolanta,W?odarczyk, Katarzyna
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p. 810 - 824
(2016/01/20)
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- Electroreduction of triphenylphosphine oxide to triphenylphosphine in the presence of chlorotrimethylsilane
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Electroreduction of triphenylphosphine oxide to triphenylphosphine in an acetonitrile solution of tetrabutylammonium bromide in the presence of chlorotrimethylsilane was performed successfully in an undivided cell fitted with a zinc anode and a platinum cathode under constant current. A plausible mechanism involving, (1) one-electron reduction of triphenylphosphine oxide generating the corresponding anion radical [Ph3P-O-], (2) subsequent reaction with chlorotrimethylsilane affording the (trimethylsiloxy)triphenylphosphorus radical [Ph3P-OSiMe 3], and (3) further one-electron reduction followed by P-O bond fission leading to triphenylphosphine is proposed. In a similar manner, electroreduction of some triarylphosphine oxides and alkyldiarylphosphine oxides was executed to give the corresponding phosphine derivatives in good to moderate yields. Georg Thieme Verlag Stuttgart · New York.
- Kawakubo, Hiromu,Kuroboshi, Manabu,Yano, Tomotake,Kobayashi, Kazuma,Kamenoue, Syogo,Akagi, Tomomi,Tanaka, Hideo
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scheme or table
p. 4091 - 4098
(2012/01/12)
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- Precursor conversion kinetics and the nucleation of cadmium selenide nanocrystals
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The kinetics of cadmium selenide (CdSe) nanocrystal formation was studied using UV-visible absorption spectroscopy integrated with an automated, high-throughput synthesis platform. Reaction of anhydrous cadmium octadecylphosphonate (Cd-ODPA) with alkylphosphine selenides (1, tri-n-octylphosphine selenide; 2, di-n-butylphenylphosphine selenide; 3, n-butyldiphenylphosphine selenide) in recrystallized tri-n-octylphosphine oxide was monitored by following the absorbance of CdSe at λ = 350 nm, where the extinction coefficient is independent of size, and the disappearance of the selenium precursor using {1H}31P NMR spectroscopy. Our results indicate that precursor conversion limits the rate of nanocrystal nucleation and growth. The initial precursor conversion rate (Qo) depends linearly on [1] (Qo(1) = 3.0-36 μM/s) and decreases as the number of aryl groups bound to phosphorus increases (1 > 2 > 3). Changes to Qo influence the final number of nanocrystals and thus control particle size. Using similar methods, we show that changing [ODPA] has a negligible influence on precursor reactivity while increasing the growth rate of nuclei, thereby decreasing the final number of nanocrystals. These results are interpreted in light of a mechanism where the precursors react in an irreversible step that supplies the reaction medium with a solute form of the semiconductor.
- Owen, Jonathan S.,Chan, Emory M.,Liu, Haitao,Alivisatos, A. Paul
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experimental part
p. 18206 - 18213
(2011/03/21)
-
- Imidazoliophosphines are true N-heterocyclic carbene (NHC)-phosphenium adducts
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Whereas the external nucleophilic reactivity of α-amidiniophosphines has been previously illustrated by their complexation to transition-metal centers, their internal electrophilic reactivity is herein investigated by using BIMIONAP (BIMIONAP=N-methylated BIMINAP cation, BIMINAP=formal contraction of the acronyms BIMIP=2,2′-bis(diphenylphosphino)-1,1′-bibenzimidazole and BINAP=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl). Reaction of tetraethylammonium chloride with free BIMIONAP is found to induce heterolytic cleavage of the N2C-P bond to give chlorodiphenylphosphine and a transient phosphine-N-heterocyclic carbene (NHC) species that is trapped in situ by protonation to the corresponding phosphine-benzimidazolium cation. When the chloride anion reacts with the cationic [Pd(η2-BIMIONAP)Cl 2] complex, the same cleavage occurs and the phosphine-NHC moiety is trapped in the corresponding [PdCl2(η2-phosphine-NHC)] complex. When the chloride anion reacts with the dicationic [Pd(π-allyl)(η2-BIMIONAP)]+ complex, allyldiphenylphosphine is produced, and the [PdCl(η2-phosphine- NHC)(PPh2CH2CH=CH2)]+ complex is obtained. Reaction of free BIMIONAP with the harder n-butyllithium nucleophile also induces heterolytic cleavage of the N2C-P bond, from which the phosphine-NHC moiety is trapped by hydrolysis of the benzimidazole ring or by P,C-sulfurization. Cleavage of a C-P bond with the weak Cl- nucleophile to release the reactive NHC moiety (according to the unusual scheme C-P+Cl-→C:+Cl-P) is a definite experimental indication of the dative nature of the N2C-P bond of amidiniophosphines, which are, therefore, better described as NHC→phosphenium adducts. This interpretation is supported by the calculation, at the DFT level, of a heterolytic dissociation mode of the N2C-P bond lower in energy than the homolytic one. A mesomeric description of the NHC→phosphenium entity is also proposed on the basis of electron localization function (ELF) and atoms in molecules (AIM) analyses. Finally ELF and AIM-based Fukui indices, molecular orbitals, and MESP analyses show that the initial attack of Cl- takes place at the carbenic atom of BIMIONAP. Addition of anionic nucleophiles (Cl-, nBu-) to free BIMIONAP and BIMIONAP-containing palladium complexes results in selective cleavage of the N2C-P bond, from which the released N-heterocyclic carbene (NHC) fragment can be trapped by protonation, hydrolysis, sulfurization, or coordination to PdII centers (see scheme).
- Abdellah, Ibrahim,Lepetit, Christine,Canac, Yves,Duhayon, Carine,Chauvin, Remi
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experimental part
p. 13095 - 13108
(2011/02/24)
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- Preparation of diphenyl phosphide and substituted phosphines using alkali metal in silica gel (M-SG)
-
Alkali metals absorbed in silica gel (the M-SG reagents) efficiently cleave C-P bonds in triaryl- and diarylphosphines. The resulting alkali metal phosphides can serve as useful building blocks for a variety of phosphines. Alkyldiarylphosphines undergo exclusive aryl group cleavage.
- Nandi, Partha,Dye, James L.,Bentley, Philip,Jackson, James E.
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supporting information; experimental part
p. 1688 - 1692
(2009/09/06)
-
- Effect of base on alkyltriphenylphosphonium salts in polar aprotic solvents
-
When arylmethyl phosphonium salts are treated with a base (e.g., t-BuOK or NaH) they homocouple to form symmetric 1,2-diarylethenes. In some cases, dilution and (or) use of excess base lead to very high yields of the product. This reaction is solvent sensitive: the reaction occurs only when polar aprotic solvents such as acetonitrile or DMSO are used. Other alkyl phosphonium salts (e.g., ethoxycarbonylmethyltriphenylphosphonium bromide and n- butyltriphenylphosphonium bromide) form a ylid (when an α-carbonyl group is present) or lose a phenyl group to form alkyldiphenylphosphine oxides when treated with the base. Mechanistic investigation of the homocoupling reaction indicates that the reaction proceeds through a ylid that acts as a nucleophile on an unreacted phosphonium salt. The resulting adduct undergoes elimination to form the observed product. The EIZ ratio seems to depend on the amount of the base used and the phosphonium salt involved.
- Ngwendson, Julius N.,Schultze, Cassandra M.,Bollinger, Jordan W.,Banerjee, Anamitro
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p. 668 - 675
(2008/09/21)
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- SHOP-type nickel complexes with alkyl substituents on phosphorus, synthesis and catalytic ethylene oligomerization
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The β-keto phosphorus ylides (n-Bu)3P=CHC(O)Ph 6, (t-Bu)2PhP=CHC(O)Ph 7, (t-Bu)Ph2P=CHC(O)Ph 8, (n-Bu) 2PhP=CHC(O)Ph 9, (n-Bu)Ph2P=CHC(O)Ph 10, Me 2PhP=CHC(O)Ph 11 and Ph3P=CHC(O)(o-OMe-C6H 4) 12 have been synthesized in 80-96% yields. The Ni(ii) complexes [N=iPh{Ph2PCHC(O=)(o-OMeC6H4)}(PPh 3)] 13, [N=iPh{Ph(t-Bu)PCHC(O=)Ph}(PPh3)] 15, [N=iPh{(n-Bu)2PCHC(O=)Ph}(PPh3)] 16 and [N=iPh{Ph(n-Bu)PCHC(O=)Ph}(PPh3)] 17 have been prepared by reaction of equimolar amounts of [Ni(COD)2] and PPh3 with the β-keto phosphorus ylides 12 or 8-10, respectively, and characterized by 1H and 31P{1H} NMR spectroscopy. NMR studies and the crystal structure determination of 13 indicated an interaction between the hydrogen atom of the C-H group α to phosphorus and the ether function. The complexes [N=iPh{Ph2PCHC(O=)Ph}(Py)] 18, [N=iPh{Ph(t-Bu)PCHC(O=) Ph}(Py)] 19, [N=iPh{(n-Bu)2PCHC(O=)Ph}(Py)] 20, [N=iPh{Ph(n-Bu) PCHC(O=)Ph}(Py)] 21 and [N=iPh{Me2PCHC(O=)Ph}(Py)] 22 have been isolated from the reactions of [Ni(COD)2] and an excess of pyridine with the β-keto phosphorus ylides Ph3PCH=C(O)Ph 3 or 8-11, respectively, and characterized by 1H and 31P{ 1H} NMR spectroscopy. Ligands 3, 8, 10 and 12 have been used to prepare in situ oligomerization catalysts by reaction with one equiv. of [Ni(COD)2] and PPh3 under an ethylene pressure of 30 or 60 bar. The catalyst prepared in situ from 12, [Ni(COD)2] and PPh 3 was the most active of the series with a TON of 12 700 mol C 2H4 (mol Ni)-1 under 30 bar ethylene. When the β-keto phosphorus ylide 8 was reacted in situ with three equiv. of [Ni(COD)2] and one equiv. of PPh3 under 30 bar of ethylene, ethylene polymerization was observed with a TON of 5500 mol C 2H4 (mol Ni)-1. The Royal Society of Chemistry.
- Kermagoret, Anthony,Braunstein, Pierre
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p. 822 - 831
(2008/09/20)
-
- METHOD FOR GENERATING ALKALI METAL PHOSPHIDES THROUGH REDUCTION OF TRI-SUBSTITUTED PHOSPHINES WITH ALKALI METAL POROUS OXIDE COMPOSITIONS
-
Alkali metal phosphides are useful intermediates for the synthesis of a variety of phosphine derivatives. Many of these phosphine derivatives are important industrial compounds with applications as synthetic intermediates or as ligands in a variety of homogeneous and heterogeneous synthetic processes. Alkali metal diarylphosphides in particular have been used in the synthesis of many phosphine ligands of importance. The invention relates to methods for generating and using alkali metal phosphides by reduction of the phosphorus sigma bonds of tri-substituted phosphorus derivatives with Group I metal/porous oxide compositions. Formula (I).
- -
-
Page/Page column 16-18
(2008/12/08)
-
- Expanding the range of "Daniphos"-type P∩P- and P∩N-ligands: Synthesis and structural characterisation of new [(η6-arene)Cr(CO)3] complexes
-
New P∩P- and P∩N-ligands have been synthesised whose core structure is an [(η6-arene)Cr(CO)3] unit. These new ligands, which extend the range of "Daniphos" ligands, are endowed with central and planar chirality and have been prepared through a stereoselective synthetic strategy from optically pure benzylamines bearing a second substituent on the arene other than the benzyldimethylamino group. Because the two faces of unsymmetrically 1,2- and 1,3-disubstituted benzylamine are diastereotopic, which means that diastereomeric complexes arise upon coordination of the Cr(CO) 3 fragment to either of these two faces, the synthetic plan has been adjusted by exploiting the trimethylsilyl group as a temporary steric modulator in order to access both complexes with high diastereoselectivity. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Alberico, Elisabetta,Braun, Wolfgang,Calmuschi-Cula, Beatrice,Englert, Ulli,Salzer, Albrecht,Totev, Daniel
-
p. 4923 - 4945
(2008/09/17)
-
- Phosphorus-carbon bond formation catalysed by electrophilic N-heterocyclic phosphines
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A P-chloro-diazaphospholene catalyses the phosphorus-carbon bond formation reaction between diphenylsilylphosphine and various alkyl chlorides. The Royal Society of Chemistry 2006.
- Burck, Sebastian,Foerster, Daniela,Gudat, Dietrich
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p. 2810 - 2812
(2008/09/19)
-
- The formation of open-chain thioesters in the reaction of 2-lithio-2-methyl- and 2-lithio-2-phenyl-1,3-dithiane with chlorodiphenylphosphane followed by oxidation
-
The unexpected formation of open-chain thioesters (3) and (6) from the reaction of 2-lithio-r-2-t-4-t-6-trimethyl (1-Li) and 2-lithio-r-2-phenyl-t-4-t-6-dimethyl-1,3-dithiane (4-Li), respectively, with chlorodiphenylphosphane followed by oxidation was observed instead of the anticipated gem-derivatives. The X-ray diffraction analysis of (6) and the trapped intermediate (10) confirmed the structure and the proposed mechanism of formation of the open-chain products.
- Gordillo, Barbara,Domínguez, Zaira J.,Sánchez, Noé,González, Ricardo,Salas, Magali,Barragán, Efraín
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p. 5293 - 5297
(2007/10/03)
-
- CsOH-promoted P-alkylation: A convenient and highly efficient synthesis of tertiary phosphines
-
A mild and efficient method for the synthesis of tertiary phosphines and ditertiary phosphines has been developed. In the presence of cesium hydroxide, molecular sieves and DMF at room temperature, various secondary phosphines and alkyl bromides were examined, and the results have demonstrated that this methodology offers a general synthetic procedure to produce tertiary phosphines in moderate to high yields. Optically active tertiary phosphine synthesis is also described.
- Honaker, Matthew T.,Sandefur, Benjamin J.,Hargett, James L.,McDaniel, Alicia L.,Salvatore, Ralph Nicholas
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p. 8373 - 7377
(2007/10/03)
-
- Synthesis of 1,2-dihydro-1,3-diaza-2λ5,4λ5-2,4- diphosphorine 2-oxides
-
The reaction of lithium (N-diphenylphosphoryl)phosphazenes with nitriles afforded 1,2-dihydro-1,3-diaza-2λ5,4λ5-2,4- diphosphorine 2-oxides through a C-regioselective addition to the cyano linkage followed by in situ cyclocondensation. The new heterocycles were designed to mimic thymine and are promising chemotherapeutic anticancer agents. As an exception, for p-nitrobenzonitrile a SNAr reaction was exclusively observed with the nucleophile entering in the ortho position of the nitro substituent in a process directed by the strong electron withdrawing effect of the NO2 group.
- Andújar, Carmen M,álvarez, Isidro Pérez,Ortiz, Fernando López
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p. 2569 - 2575
(2007/10/03)
-
- Reactions of lithiated P-diphenyl(alkyl)(N-methoxycarbonyl)phosphazenes with Michael acceptors and aldehydes. Synthesis of 1H-1,2-azaphosphinin-6-ones, β-hydroxy(N-methoxycarbonyl)phosphazenes and 5,6-dihydro-1,3,4-oxazaphosphinin-2-ones
-
Lithium (N-methoxycarbonyl)phosphazenes add C-regioselectively to DMAD, dimethyl malonate, fumarate, and butylidenmalonate in a [1,4] manner. Only one diastereoisomer is observed with the olefinic electrophiles. With DMAD the initial adduct evolves through cyclocondensation with the CO2Me group of the phosphazene and 1H-1,2-azaphosphinin-6-ones are obtained. Exceptionally, methyl phenylpropiolate reacted exclusively through the carbonyl yielding a mixture of C- and N-acylated compounds. The addition to aldehydes at -80°C affords β-hydroxyphosphazenes diastereoselectively. For lithium α,α-dimethyl(N-methoxycarbonyl)phosphazenes, the intermediate alkoxides cyclocondense at room temperature to 5,6-dihydro-1,3,4-oxazaphosphinin-2-ones.
- álvarez-Gutiérrez, Julia M,Peralta-Pérez, Emma,Pérez-álvarez, Isidro,López-Ortiz, Fernando
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p. 3075 - 3086
(2007/10/03)
-
- Stereoselective Synthesis of 1,2,5,6-Tetrahydro 1,3-Oxaza-4-phospha-2-phosphorine 2-Oxides through Reaction of P-Diphenyl(alkyl) (N-diphenylphosphoryl)phosphazenes with Aldehydes and Ketones
-
Novel 1,2,5,6-tetrahydro 1,3-oxaza-4-phospha-2-phosphorine 2-oxides have been synthesised stereoselectively through addition of aldehydes and ketones to lithiated (N-diphenylphosphoryl)phosphazenes.
- Perez, Emma Peralta,Ahrens, Birte,Davidson, Matthew G.,Raithby, Paul R.,Teat, Simon J.,Alvarez, Isidro Perez,Ortiz, Fernando Lopez
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p. 275 - 277
(2007/10/03)
-
- Structural and Solid-State 31P N.M.R. Studies of Tetrameric 1:1 Butyldiphenylphosphine Complexes of Silver(I) Halides
-
Tetrameric 1:1 complexes of butyldiphenylphosphine (PPh2Bu) with silver halides AgX (X = Cl, Br and I) have been synthesized, and characterized in the solid state by single-crystal X-ray diffraction studies and solid-state 31P n.m.r.Crystals of 4 and 4 are isostructural, crystallizing in the tetragonal space group I with a 16.853(4), c 11.697(4) Angstroem and R 0.060 for 999 "observed" reflections for X = Cl, and a 16.944(4), c 11.893(9) Angstroem and R 0.044 for 835 "observed" reflections for X = Br.The structures consist of "cubane" units with core distances of Ag-P 2.365(8), Ag-Cl 2.712(7), 2.682(6) and 2.569(6) Angstroem for the chloride, and Ag-P 2.408(6), Ag-Br 2.819(3), 2.806(3) and 2.670(3) Angstroem for the bromide.Crystals of 4 crystallize in the same space group with similar cell dimensions, a 16.559(4) and c 12.819(3) Angstroem, and R 0.053 for 638 "observed" reflections.However, the tetramers in this complex are rotated by 45 deg around the c axis with apparent relaxation of strain at the Ag-P bond.The ligand conformation is such that the butyl groups are oriented along the c axis rather than lying in the ab plane as found for the chloride and bromide structures.The bond distances for the I3AgP core are Ag-P 2.43(1), Ag-I 2.928(4), 2.882(4) and 2.885(4) Angstroem.The ligand substituents in this complex exhibit very high thermal motion although no disorder is resolved.Solid-state CPMAS 31P n.m.r. spectra of the chloride and bromide complexes each show a simple doublet with line spacing of 640 and 595 Hz respectively assignable to 1J(107,109Ag,31P) scalar coupling.The spectrum of the iodide complex, however, consists of a broad single peak suggestive of a high degree of disorder in the crystal lattice, consistent with the structural results.
- Bowen, Richard J.,Camp, David,Effendy,Healy, Peter C.,Skelton, Brian W.,White, Allan H.
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p. 693 - 702
(2007/10/02)
-
- ELECTROCHEMICAL SYNTHESIS OF TERTIARY PHOSPHINES FROM ORGANIC HALIDES AND CHLOROPHOSPHINES
-
The electrochemical synthesis of a wide range of tertiary mono- and diphosphines has been achieved in very simple and mild conditions, in an undivided electrolytic cell with a sacrificial anode of magnesium.
- Folest, J. C.,Nedelec, J. Y.,Perichon, J.
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p. 1885 - 1886
(2007/10/02)
-
- A Simple Synthesis and Some Synthetic Applications of Substituted Phosphide and Phosphinite Anions
-
Based on data for the acidity relationship of phosphines and phosphinous acids and water in dimethyl sulfoxide and water, a simple method is reported for the generation of phosphide and phosphinite anions by the action of concentrated aqueous alkali on primary and secondary phosphines as well as phosphinous acids in dimethyl sulfoxide or other dipolar aprotic solvents.Alkylation of the anion yields secondary and tertiary phosphines, polyphosphines, functionally substituted phosphines as well as similarly substituted phosphine oxides.Phosphinous acids have beenalkylated in various solvents in two-phase systems containing concentrated aqueous alkali and tetrabutylammonium iodide as phase transfer catalyst.
- Tsvetkov, E. N.,Bondarenko, N. A.,Malakhova, I. G.,Kabachnik, M. I.
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p. 198 - 208
(2007/10/02)
-