Bis-phosphonium Salts Research Articles

Kumulierte Ylide, 22. Umsetzungen von (Triphenylphosphoranyliden)ethenon mit Halogenverbindungen und ihre präparative Anwendung

Cumulated Ylides, 22. — Reactions of (Triphenylphosphoranylidene)ethenone with Halogen Compounds and their Preparative Application(Triphenylphosphoranylidene)ethenone (6) reacts with halogen compounds 7 to yield four‐membered ylide phosphonium salts 9. Ring opening of 9 under different conditions gives rise to the formation of bis‐ylides 13, ylide salts 14, or bis‐phosphonium salts 15. Compounds 13/14 are hydrolysed to mono‐ylides 16, and the Wittig reaction with aldehydes yields unsaturated acylphosphoranes 17, which on thermolysis afford enyne carboxylic esters 18. From the bis‐salts 15 α‐branched divinyl ketones 22 are available by bis‐Wittig reaction.

ChemInform Abstract: Synthesis of Bis(phosphinomethyl)amines via Bis(hydroxymethyl) phosphonium Salts. Isolation of 9,9‐Bis(hydroxymethyl)‐9‐ phosphoniabicyclo(3.3.1)nonane Hydrogensulfate and Chloride Salts, and the Crystal Structures of (PPh2(CH2OH)2)+Cl‐ and ((C6H11)2PCH2) 2NCHMePh.

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Phosphenium Complexes of the Chromium and Iron Group: Novel Cycloaddition Reactions and the Chemistry of PH-Functional and Chiral Derivatives1

Abstract Synthesis of the highly reactive phosphenium complexes C5R5(CO)2M-P(H)R′ (R [dbnd] H, Me; R′ [dbnd] t-Bu, Mes, s-Mes) (2a-d) is described. The mesityl derivative shows spontaneous dimerization to give the dinuclear species C5R5(CO)2W[dbnd]P(Mes)-W(CO)(PH2Mes)C5R5 (6a, b), a new type of phosphinidene complex. An alternative access to these species involves deprotonation and decarbonylation of the bis (metallo) phosphonium salts {[Cp(CO)2W]2P(Mes)H}BF4 (9a, b). Cycloaddition reaction of the phosphenium complexes Cp(CO)(HPh2P)M[dbnd]PPh2 (Mo, W) (16a, b) and Cp(CO)Fe[dbnd]PMes2 (18a, b) respectively with isothiocyanates yields novel fourmembered phosphametallacycles LnM-PR2-C(NR′)-S (R′ [dbnd] Et, t-Bu) (17a, b, 18a, b).

Structural characterization of mono‐ and bisphosphonium salts by fast atom bombardment mass spectrometry and tandem mass spectrometry

AbstractPositive‐ion fast atom bombardment (FAB) mass spectra are reported for a representative series of mono‐ and bisphosphonium halides derived from triphenylphosphine. The mass spectra of the monoalkyltriphenylphosphonium salts typically contain abundant intact cations that can be used to establish the cationic relative molecular mass and diagnostic fragment ions that allow the characterization of structural subgroups. Depending on the functional group substitution on the alkyl group, additional fragment ions are observed which are formed by loss of small neutral molecules from the intact cation and that can be used for the differentiation of isomeric phosphonium salts. Molecular dication are typically observed in the FAB mass spectra of the bisphosphonium salts when they are analysed in 3‐nitrobenzyl alcohol. In addition, production of singly charged ions by clustering with a counter ion, decomposition involving removal of one of the charge centres and one‐electron reduction are generally observed. Structurally diagnostic fragments are also obtained. The fragmentation pathways of the ions derived from the phosphonium salts were elucidated by precursor ion and product ion tandem mass spectrometric experiments. For the phosphonium salts containing a long‐chain hydrocarbon alkyl group, high‐energy collision‐induced decomposition of the intact cation is needed to obtain unambiguous structural information.

Synthesis of bis(phosphinomethyl)amines via bis(hydroxymethyl)phosphonium salts. Isolation of 9,9-bis(hydroxymethyl)-9-phosphoniabicyclo[3.3.1]nonane hydrogensulfate and chloride salts, and the crystal structures of [PPh2(CH2OH)2]+ Cl? and [(C6H11)2PCH2]2NCHMePh

Phosphines of the type PR2H reacted readily with formaldehyde in the presence of acid to afford high yields of bis(hydroxymethyl)phosphonium salts [PPh2(CH2OH)2]+X–, [P(C6H11)2(CH2OH)2]+X–, [[graphic omitted]H2]+X–, and [[graphic omitted]H2]+X–(X = Cl or HSO4). Treatment of the mixed isomers of the bicyclononane phosphonium cation [P(C8H14)(CH2OH)2]+ in boiling H2SO4 gave a [3.3.1] isomer, the [4.2.1] isomer undergoing decomposition. A single-crystal X-ray diffraction study has been carried out on the phosphonium salt [PPh2(CH2OH)2]+Cl–. The geometry around phosphorus is essentially tetrahedral, and there is hydrogen bonding between the hydroxyl groups and the chloride anion. Treatment of these phosphonium salts with triethylamine and a primary or secondary amine afforded aminomethylphosphines (R2PCH2)2NR′(R = Ph, R′= CHMePh, CHMeCO2Me, CHMeCO2Et, [graphic omitted]CMe2, CH2CH2OH or CH2CHCH2; R = C6H11, R′= CHMePh or CHMeCO2H; R2= C8H14, R′= CHMePh) or C8H14PCH2NEt2 in good yields. A single-crystal X-ray diffraction study has been carried out on [(C6H11)2PCH2]2NCHMePh.

Neue methode zur regiospezifischen substitution einiger reaktionsträcer N-heteroaromatischer ringsysteme

N-Trifluoromethanesulfonyl-heteroarylium salts 1 react with phosphanes 2 to give the C4- or C2-substituted products 4 or 5 . By means of a similar procedure, bisphosphonium salts 6 and 7 are formed. The reaction of sodium azide ( 8 ), and 6 yields the iminophosphorane 10 via the intermediate 9 .

Reactions of o-quinones with some bis-phosphonium salts in the presence of lithium ethoxide

Reactions of the 1,3-bis-phosphonium salts (2a–d) with phenanthrene-9,10-quinone (1) in the presence of lithium ethoxide gave the phenanthro derivatives (3), (4), (5), and (7) respectively, instead of the expected bis-Wittig reaction products. However, from the reaction of the salt (2c) the bis-Wittig product (6) was also obtained, but in very low yield. On the other hand, reactions of 1,6- and 1,5-bis-phosphonium salts (18) and (26) with o-quinones (1), (20), and (21) resulted in the formation of 9-(o-hydroxyaryl)phenanthrenes (22)–(24) and 1-(o-hydroxyaryl)acenaphthylenes (28) and (29). Reaction mechanisms involving initial Wittig reaction of one carbonyl group with one ylide group are proposed. Bromination of (22) and (28) and dehydrobromination of the bromo derivatives (33) and (35) produced gave the annelated furan derivatives (34) and (36) respectively.

Nouvelle synthese stereoselective de disels de botadiene-1,3 ylene-1,4 bisphosphoniums

A new way to 1,4 butadienylene bisphosphonium salts 2 is given, using a base-catalyzed double isomerization process on acetylenic precursors 3 . The precursor can be synthetized by nucleophilic substitution of 1,4-diiodo 2-butyne with triphenylphosphine. The selection of the 1,4-dihalo 2-butyne has a strong influence on the course of the reaction which, besides that, can lead to exclusive formation of a new stabilized ylid-disalt 5 . The stereoselectivity of the t.butylamine induced double isomerization allows the isolation of the kinetic product, the (Z, E) 1,4-butadienylene bisphosphoniun salt, which is then readily converted into the more stable (E, E) isomer.

Electrochemical reduction of 1,2-vinylene and 1,4-butadienylene bis-phosphonium salts

The electrochemical reduction of 1,2-vinylene and 1,4-butadienylene bis-phosphonium salts has been investigated on a mercury cathode in unbuffured or acidic hydroorganic media. It is controlled by ylid character of the radical obtained after the first electronic transfer. This ylid character induces an heterolytic PC bond breaking with the unsaturated bridge. This result parallels those obtained in the chemical reduction of the same structures and confirms the high fragility of the bridge.

A general synthesis of optically active phosphines, phosphinites and thiophosphinites from alkylthio(alkylseleno)phosphonium salts and tris(dimethylamino)phosphine as a thiophilic agent

Tris(dimethylamino)phosphine was found to be a suitable thiophilic reagent which converts optically active alkylthio(alkylseleno)phosphonium salts into chiral tertiary phosphines and phosphinites with a high stereoselectivity. The first synthesis of optically active thiophosphinites from bis(alkylthio)phosphonium salts and tris(dimethylamino)phosphine is also reported.

Synthesis and Reactivity of Unsaturated Bisphosphonium Salts

Abstract The synthesis of 1, 2 vinylene bisphosphonium salts 1 has now been enlarged to the vinylogous 1, 4-butadienylene bisphosphonium salts 2. The salts 2, a new class of unsaturated disalts, have also been prepared through a two-step isomerisation of acetylenic salts. New aspects of the reactivity of salts 1 and the comparative study of salts 2 (selective cleavage reactions of P-C bonds and reactions with nucleophiles having a mobile hydrogen) are described. This reactivity allows the preparation of new series of phosphonium salts substituted by heteroatomic groups.

Preparation and synthetic utility of fluorinated phosphonium salts, bisphosphonium salts and phosphoranium salts

The synthesis and mechanism of formation of phosphonium salts of the type [R 3 P + CFXY]Z − (where X = F, Cl, Br; Y = Br, Cl; Z = Br, Cl), bis -phosphonium salts of the type [R 3 P + CF 2 P + R 3]2Br −, and phosphoranium salts of the type [R 3 P +  C − F P + R 3]X − (X = Br, Cl) will be presented. The applicability of these substrates in the generation of useful nucleophilic or electrophilic synthetic intermediates will be discussed.

Separation of mono- and bis-phosphonium salts by preparative HPLC

Development and application of a preparative HPLC method for the separation of phosphonium salts is described. Analytical chromatograms obtained by means of ion-pair chromatography as well as adsorption chromatography in the presence or absence of acid are presented. A description of successful preparative separations is also given. The chromatographic fractions were identified by 1H- and 31P-NMR spectroscopy.

Dipyrazolinyl-substituted 1,4-distyrylbenzenes

A number of dipyrazolinyl-substituted 1,4-distyryl- and 1,4-distyryl-2-methylbenzenes — new luminophores that have intense yellow-green luminescence — were obtained by the Wittig reaction by refluxing 1-(4-formylphenyl)-3-aryl-5-phenyl-2-pyrazolines and aromatic bisphosphonium salts in isopropyl alcohol in the presence of sodium isopropoxide. The low reactivities of the aldehydes used and the predominant formation of trans isomers in the Wittig reaction are noted. Data from the IR and electronic absorption spectra and the fluorescence spectra of the synthesized compounds are presented.

Funktionelle Trimethylphosphinderivate, VIII Phosphoniumsalze, Oxide und Sulfide von Tetraorganodiphosphinomethanen, R2PCH2P(CH3)2/ Functional Derivatives of Trimethylphosphine, VIII Phosphonium salts, Oxides and Sulfides of Tetraorganodiphosphinomethanes, R2PCH2P(CH3)2

Abstract Tetramethyldiphosphinomethane (CH3)2PCH2(CH3)2 (1a) reacts with HCl/ether to form the mono-and bisquaternary salts [(CH3)2PCH2P(H)(CH3)2]Cl (2) and [(CH3)2(H)PCH2P(H)(CH3)2]Cl2 (3), respectively. The system 1a/HCl, incorporating 1 a/2/3, represents a useful tool for studying the appearance of XnAA′X′n-spin type systems. These compounds are also prototypes for a variety of other mono-or bis-phosphonium salts, which are formed in the reactions of the diphosphines (CH3)2PCH2PR2 (R = CH3, t-C4H9, C6H5) (1a-c) with (CH3)2CO + HCl, CH3I, t-C4H9Br, C6H5COCl, (CH3)2PCl and Br(CH2)nBr (n = 1, 2). Heterocycles are not obtained. The dioxide 14 and the disulfide 15 are also described. Some properties and spectroscopic data (IR, 1H, 31P and 13C NMR) of 26 new compounds are reported and briefly discussed.

Phosphonium salts. III. The action of cyanide ion and other nucleophiles on some bis-phosphonium salts

Cyclic and acyclic bis-phosphonium salts with a two-carbon bridge are smoothly cleaved to phosphines in high yield by potassium cyanide in dimethyl sulphoxide. Evidence is presented that the reaction proceeds by an elimination-addition sequence. An elimination reaction also occurs when sodium methoxide, sodium azide, sodium acetate, and triethylamine react with ethane-1,2-bis(tri-phenylphosphonium) dibromide. ��� In a novel reaction, triphenylphosphine is converted into its oxide by a mixture of sodium azide and dimethyl sulphoxide.

Phosphonium salts. II. The reaction of bis-phosphonium salts with metal hydrides

Ethane-1,2-bis-phosphonium salts are cleaved by sodium hydride to phos- phines in 55-80% yields with loss of the two-carbon bridge. The reaction is independent of the substituents at the phosphorus atoms. The same reaction is observed with an ethene-1,2-bis-salt and with but- 2-ene-1,4-bis(triphenylphosphonium) dibromide. It is suggested that a phosphorane is formed which subsequently fragments in a manner analogous to alkaline hydrolysis. ��� Lithium aluminium .hydride behaves similarly but loss of the bridge is competitive with loss of benzyl groups, and yields are generally better (> 70%).

Phosphonium salts. I. The alkaline hydrolysis of some bis-phosphonium salts

Ethane- and ethene-1,2-bisphosphonium salts are cleaved by alkali into a phosphine and a phosphine oxide with loss of the two-carbon bridge. When the phosphorus atom carries benzyl substituents, loss of the benzyl groups is competitive with loss of the bridge. ��� Based on a kinetic study, a synchronous mechanism, analogous to the alkaline hydrolysis of acyclic monophosphonium salts, is proposed to account for the fragmentation. ��� With 6-membered 1,4-diphosphonio heterocyclic salts the nature of the products is dependent on whether alkali or phosphonium salt is present in excess. With an excess of alkali a synchronous mechanism again appears to operate, while with an excess of salt the reaction proceeds stepwise and without loss of the bridge. A partial explanation of these facts is advanced in terms of non-bonded interactions in the intermediate phosphoranes. ��� The synchronous reaction appears to be favoured by coplanarity of the P-C-C-P system.

Protonation, quaternisation, and stereochemistry of 2,2′-biphenylylene-bisdimethylamine. The thermal decomposition of related salts and the mechanism of cyclisation of 2,2′-diaminobiphenyl to carbazole

The reaction of the ditertiary amine, 2,2′-biphenylylenebisdimethylamine, with methyl iodide has been re-examined and shown to give both the monohydriodide and monomethiodide. The H n.m.r. spectra of the above salts have been studied and provide examples of magnetic nonequivalence of methyl groups attached to nitrogen in a dissymmetric system.The thermal decomposition of the above salts, and of 2,2′-diaminobiphenyl dihydrobromide, has been examined; the results suggest that the formation of carbazole from 2,2′-diaminobiphenyl on heating with acid proceeds via an SNi mechanism, as has been suggested for the conversion of related bisphosphonium salts to phosphafluorenes.

The hydrolysis of bisphosphonium salts

The hydrolysis of bisphosphonium salts