Reaction Of Tertiary Phosphines Research Articles

Non-Classical Molecular Activation by Phosphines and N-Heterocyclic Carbenes and Its Application to Catalytic Reactions

Abstract This Award Account reports our recent studies concerning the catalytic transformations that involve a non-classical mode of molecular activation by tertiary phosphines and N-heterocyclic carbenes (NHCs). Regarding organophosphine catalysis, we successfully designed reactions based on a P(III)/P(V) redox couple. A catalytic protocol for generating pentacoordinate P(V) species was devised by the reaction of tertiary phosphines, acyl fluorides and alkynoates. The ability of the thus generated fluorophosphoranes to participate in ligand coupling and ligand metathesis with organosilicon nucleophiles enables synthetic transformations that are otherwise unattainable, including the intermolecular carbofluorination of alkynes and the hydroalkenylation of enol ethers. Regarding nucleophilic NHC catalysis, the use of imidazolium-based NHCs can generate deoxy-Breslow intermediates that are sufficiently nucleophilic to promote the aromatic substitution of aryl halides, aryl ethers and anilides. The protocol can also be used for the nucleophilic activation of styrene derivatives, allowing for the generation of a series of ylide intermediates that can serve as non-stabilized vinyl anion equivalents. These results demonstrate that synthetic transformations involving non-stabilized carbanions can be conducted under catalytic conditions without the use of strong organometallic nucleophiles.

Reactions of Tertiary Phosphines with 3-Halogen-1,2-naphthoquinones as a New Synthetic Approach to 3,3′,4,4′-Tetrahydroxy-1,1′-binaphthyls

A mild and efficient method for the synthesis of new tetrahydroxy-1,1′-binaphthyls containing a halogen atom in the position 3 of the naphthalene moiety was developed. The structure of the tetrahydroxy-1,1′-binaphthyls complexes with the corresponding phosphine oxides was established by NMR spectroscopy.

Solvent Effect on Kinetics and Mechanism of the Phospha‐Michael Reaction of Tertiary Phosphines with Unsaturated Carboxylic Acids

ABSTRACTIn aprotic solvents, kinetics of the reaction of triphenylphosphine with acrylic acid is second order in the acid and first order in the phosphine. To find the most suitable model to describe the solvent effect on this reaction, the third‐order rate constants in a series of 16 aprotic solvents were analyzed using one‐ and multiparameter regressions within the framework of the Kamlet–Taft, the Catalán, the Gutmann–Mayer, and the Koppel–Palm equations. The best result gives a two‐parameter model constructed on the basis of the Reichardt polarity ET and the basicity B from the Koppel–Palm equation, with the weak positive effect of the ET parameter on the reaction rate and very strong negative effect of the B parameter. The results obtained give further evidence to the previously suggested a stepwise mechanism, which involves the initial formation of a zwitterionic intermediate, followed by the proton transfer from the second molecule of acrylic acid to the generated carbanionic center in the rate‐determining step.

Quantum chemical investigation on the reaction mechanism of tertiary phosphines with unsaturated carboxylic acids: An insight into kinetic data

AbstractThe structures of intermediates and transition states in the reaction of tertiary phosphines with unsaturated carboxylic acids have been calculated at the B3LYP level of theory using the 6‐31+G(d,p) basis set. Analysis of the results shows that [1,3]‐intramolecular migration of carboxylic proton to carbanionic center of generated zwitterionic intermediate is strongly kinetically unfavorable, and external proton‐donor source is essential to complete quaternization. A molecular cluster of the intermediate with one molecule of water has been modeled for intermolecular reaction pathway, but even in this case, the proton transfer remains to be the rate‐determining step that is in a good agreement with previous kinetic investigations on this reaction. The data obtained for this reaction have much in common with recent studies on the mechanisms of the Morita–Baylis–Hillman reaction and phosphine‐catalyzed [3+2] cycloaddition, which revealed paramount importance of proton‐transfer steps. © 2013 Wiley Periodicals, Inc.

Kinetics and Mechanism of Triphenylphosphine Quarternization with Unsaturated Carboxylic Acids in Various Media

Reactions of tertiary phosphines with unsaturated electrophilic reagents are widely used in synthetic organic chemistry. Typical satellites of these transformations are proton migration processes, which can play decisive role in such reactions. To learn more about proton transfer mechanism, kinetics of reaction of triphenylphosphine with a series of unsaturated carboxylic acids in alcohols, carboxylic acids, and aprotic solvents was studied by spectrophotometry. The form of kinetic equation depends on proton–donor properties of solvent and has a general third order. Proton transfer occurs from the solvent in carboxylic acids; the second molecule of substrate is required in aprotic solvents, and both canals of proton migration take place in alcohols. Existent proton transfer canals are isokinetic, attesting to the invariability of general features of the reaction mechanism independent of proton–donor nature at the last step of the interaction. A stepwise mechanism including initial generation of 1,3-dipole followed by proton transfer to the carbanionic centre from the medium is suggested.

ChemInform Abstract: Reaction of Tertiary Phosphines with Phenylacetylene in the Presence of Proton Donating Reagents.

ChemInform Abstract: Reaction of Tertiary Phosphines with Phenylacetylene in the Presence of Proton Donating Reagents.

New phosphorus ylides in reactions of tertiary phosphines with phosphorylated quinone methide

A series of new phosphonium ylides have been synthesized by the reaction of dimethyl-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadienylidene)methylphosphonate with tertiary phosphines, the structure of dimethoxyphosphoryl-3,5-di-tert-butyl-4-hydroxyphenylmethylidene triphenylphosphorane has been confirmed by X-ray single crystal diffraction.

Reactions of Tertiary Phosphines with Alcohols in Aqueous Media

The phosphines R(2)R'P [R = R' = Me, Et, (n)Pr, (i)Pr, (CH(2))(3)OH; Me(2)PhP and MePh(2)P] react with 2- or 4-hydroxybenzyl alcohols, including "lignin-type" vanillyl, syringyl, and alpha-methylvanillyl alcohols, in a 1:1 ratio in aqueous media, to give zwitterionic phosphobetaine products; these on treatment with aq HCl form the corresponding phosphonium chlorides in good to excellent yields. The syringyl derivative [3,5-(OMe)(2)-4-OH-C(6)H(2)CH(2)PEt(3)]Cl was structurally characterized by X-ray analysis. Kinetically, the reactivity of the benzyl alcohols, studied with the water-soluble [HO(CH(2))(3)](3)P, decreases with substituents in the order 2-hydroxy > 4-hydroxy > vanillyl > syringyl > alpha-methylvanillyl, while 3-hydroxybenzyl alcohol is unreactive; the trend is consistent with reactivity requiring the presence of an ortho- or para-OH substituent in the aromatic ring of the alcohol, and that the reactions proceed via a carbocation species stabilized as a quinone methide. Triethylphosphine reacts with coniferyl alcohol at the C=C moiety to give a zwitterionic intermediate that is again converted by aq HCl to a phosphonium chloride; no reaction was observed with cinnamyl alcohol. The effect on a phenolic pK(a) by incorporation of a phosphonium substituent is also measured.

The Synthesis and Reactions of Betaines Formed in Reactions of Tertiary Phosphines with Unsaturated Carboxylic Acids and Their Derivatives

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

The synthesis and reactions of betaines formed in reactions of tertiary phosphines with unsaturated carboxylic acids and their derivatives

AbstractOn the basis of our systematic investigations, the main trends concerning synthesis, structure, and reactivity of carboxylate phosphabetaines—phosphorus analogs of organic aminoacids—are considered and analyzed. A wide series of phosphabetaines has been obtained in reactions of tertiary phosphines with unsaturated mono‐ and dicarboxylic acids, and also with their derivatives—esters and amides. By a plethora of experimental and theoretical methods, it has been shown that the thermodynamic stability of carboxylate phosphabetaines essentially depends on the structure of the initial phosphine and carboxylic acid. In some cases, the reaction between them is equilibrated. On the other hand, for a number of synthesized betaines, it is reliably established that these exist in equilibrium with isomeric phosphoranes. The extremely important condition for stabilization of phosphabetaine structures is the presence of proton‐donating reagents, which are included in their crystal lattice. In the series of symmetrically substituted derivatives, the interesting phenomenon of phosphorotropy of the phosphonium group is established. The reactivity of phosphabetaines in reactions with electrophilic reagents (haloid alkyls and acyls, isocyanates, corbodiimides) has been investigated. The majority of key structures have been confirmed by the direct X‐ray method. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:557–566, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20276

The reaction of tertiary phosphines with (Ph2Se2I2)2—the influence of steric and electronic effects

The reaction of (Ph(2)Se(2)I(2))(2) with a wide variety of tertiary phosphines possessing different steric and electronic properties has been studied, leading in most cases to R(3)PSe(Ph)I adducts; [R(3)P = (p-CH(3)C(6)H(4))(3)P (1), (m-CH(3)C(6)H(4))(3)P (2), (o-OCH(3)C(6)H(4))(3)P (4), Ph(2)MeP (6), Me(2)PhP (7), Me(3)P (8), Cy(3)P (9)]. All of the products formed were characterised by elemental analysis, Raman and multinuclear NMR spectroscopy. Both steric and electronic factors are important in determining the structural motif (CT vs. ionic) observed in the solid-state. In general, highly basic phosphines result in a lengthening of the Se-I interaction, and a preference for an ionic structure. The reaction with (o-CH(3)C(6)H(4))(3)P does not yield a stable R(3)PSe(Ph)I adduct, and instead (o-CH(3)C(6)H(4))(3)PI(2) (3) is formed. The unusually long P-I bond, [2.5523(12) A], and short I-I bond, [3.0724(4) A], exhibited by is a result of the high steric requirements of this phosphine. The similarly bulky (o-SCH(3)C(6)H(4))(3)P yields a mixture of (o-SCH(3)C(6)H(4))(3)PSe(Ph)I (5a) and [(o-SCH(3)C(6)H(4))(3)PSePh]I(3) (5b). The crystal structures of (m-CH(3)C(6)H(4))(3)PSe(Ph)I, 2, (o-CH(3)C(6)H(4))(3)PI(2), 3, [(o-OCH(3)C(6)H(4))(3)PSePh]I.CH(2)Cl(2), 4, [(o-SCH(3)C(6)H(4))(3)PSePh]I(3), 5b, two pseudo-polymorphs of Ph(2)MePSe(Ph)I, 6a/6b, and [Me(3)PSe(Ph)I](2).CH(2)Cl(2), 8, are reported. The R(3)PSe(Ph)I adducts formed exhibit one of four types of behaviour. Type I products, (such as 2) are CT in the solid-state and display fluxionality in solution. Type II products (such as 6a/6b) lie close to the CT/ionic structural borderline, displaying long Se-I bonds, and are more appropriately classified as [R(3)PSePh] (acceptor)/I(-) (donor) CT complexes. Type II complexes ionise in solution to [R(3)PSePh]I. Type III products, such as 8, are ionic in solution, but frequently show cation-anion, or cation-solvent interactions in the solid-state, although these interactions are weak and the linear P-Se-I motif is lost. Type IV products (such as 4) are ionic and feature bulky phosphines. They display no short cation-anion interactions in the solid-state.

New Synthesis of Buta-1,3-diene-1,4-diylbis(triphenylphosphonium Chloride)

In our research on reactions of tertiary phosphines with unsaturated halides we could develop one more synthetic approach to buta-1,3-diene-1,4-diylbis(triphenylphosphonium chloride) directly by the reaction of triphenylphosphine with 2,3,4-trichlorobut-1-ene. Preliminary data show that, of the possible reaction pathways, the most probable is the pathway involving initial attack of the phosphine on the terminal spcarbon atom with expulsion of the allyl chlorine atom and subsequent conversions by the following scheme.

Kinetics and Mechanism of Nucleophilic Substitutions on Coordinated Polyenes and Polyenyls. 1. Reactions of Tertiary Phosphines with [Ru(η5-C5H5)(η4-C5H4O)(L)]CF3SO3 (L = CH3CN, Benzonitrile, Thiourea, Pyridine)

Kinetics and Mechanism of Nucleophilic Substitutions on Coordinated Polyenes and Polyenyls. 1. Reactions of Tertiary Phosphines with [Ru(η⁵-C₅H₅)(η⁴-C₅H₄O)(L)]CF₃SO₃ (L = CH₃CN, Benzonitrile, Thiourea, Pyridine)

Reactions of tertiary phosphines, phosphites, and arsines with [Ru(.eta.5-C5H5)(.eta.4-C5H4O)]+ derivatives: x-ray structures of [Ru(.eta.5-C5H4PCy3)(.eta.5-C5H4OH)]+, [Ru(.eta.5-C5H5)(.eta.4-C5H4O)(P(OPh)3]+, and [Ru(.eta.5-C5H5)(.eta.4-C5H3O-2-PPh3)(MeCN)2+

Treatment of [Ru(η 5 -C 5 H 5 )(η 4 -C 5 H 4 O)] 2 (PF 6 ) 2 (1) with PR 3 (R=Me, Cy, Ph) and AsMe 3 results in the formation of 1,1'-disubstituted ruthenocenes of types [Ru(η 5 -C 4 H 4 PR 3 )(η 5 -C 5 H 4 OH)]PF 6 and [Ru(η 4 -C 5 H 4 -OH)]PF 6 , respectively, in 50-60% yield

Synthese und Reaktionen der P‐Halogen‐phosphonium‐ylide, R2P(X)=CR2

AbstractP Halogeno phosphonium ylides are readily available reagents possessing high activity and various chemical properties. Several methods exist for the synthesis of P halogeno phosphonium ylides: reaction of tertiary phosphines with carbon tetrachloride, dehydro‐halogenation of phosphonium salts, and halogenotropic rearrangement of α‐halogenoalkylphosphines. The interaction of P halogeno phosphonium ylides with carbonyl Compounds yields [2 + 2] ‐cycloaddition products which, depending on their structure, decompose to form allylphosphonates, vinylphosphonates, organophosphorus ketens, thioketens or ketenimines. P Halogeno phosphonium ylide posses a high phosphorylating ability. Their P=C double bond readily adds different nucleophiles, containing mobile hydrogen to form phosphonium salts. The reversible migrations of the chlorine atom from α‐carbon atom to the phosphorus atom proceeding with the change of phosphorus coordination number PIV ⇌ PIII are typical for P halogeno phosphonium ylides.

Thiocetenes phosphores

The reaction of tertiary phosphines R 2(R′CH 2)P with CCl 4 and CS 2 gives stable phosphorylated thioketenes

Preparation and synthetic utility of fluorinated phosphonium salts, [formula omitted]-phosphonium salts and phosphoranium salts [1

The reaction of tertiary phosphines with fluorohalomethanes provides a rapid and high yield synthesis of various types of fluorinated phosphonium salts, bis -phosphonium salts and phosphoranium salts. These salts are useful precursors to fluorine-containing ylides, carbenes and methide ions. Examples of the preparation, mechanism of formation, and synthetic utility of these novel reagents is described.

Preparation and utilisation of organometallic ylids containing the tricarbonyliron unit

The reaction of tertiary phosphines, PR3, with six- and seven-membered ring dienyl complexes of Fe(CO)3 produces the corresponding phosphoniodiene salts. These salts undergo deprotonation on treatment with either LiBun or NaH and undergo a subsequent reaction with aldehydes (R′CHO) to yield the appropriate olefinic complexes. With [Fe(CO)3(η-C5H5)][BPh4], reaction with PR3 produces simple substitution complexes of the type [Fe(CO)2(η-C5H5)(PR3)][BPh3]. Treatment of [Fe(CO)3(C8H7CH2OH)] with HPF6 produces a salt of unknown structure which reacts with PPh3 to produce tricarbonyl(triphenylphosphoniomethylcyclo-octatetraene)iron hexafluorophosphate. Reaction of this salt with LiBun and HCHO yields tricarbonyl(vinylcyclo-octatetraene)iron.

Kinetics of nucleophilic attack on co-ordinated organic moieties. Part 7. Mechanisms of addition of tertiary phosphines and phosphites to tricarbonyl(dienyl)iron cations

The reaction of tertiary phosphines and phosphites with dienyl complexes such as [Fe(C6H7)(CO)3][BF4](1) provides a general route to phosphonium adducts of the type [Fe(C6H7·PR3)(CO)3][BF4](R = Ph, p-tolyl, Bun, OPh, or OBun). An analogous reaction with 1,2-bis(diphenylphosphino)ethane leads to the dimeric salt [Fe2{( C6H7·Ph2PCH2)2}(CO)6][BF4]2. The rate law, Rate =k[Fe][PR3], is observed for addition of a range of phosphines and phosphites to (1) and the related cations [Fe(C6H6OMe)(CO)3]+ and [Fe(C7H9)(CO)3]+. Rate and activation parameters indicate direct addition at the dienyl rings. The marked dependence of k on the basicity of phosphorus nucleophiles suggests significant bond making in the transition states for adduct formation.

Reactions of tertiary phosphines with (CH 3) 3SnCH 2I

The reactions of (OC) 5WPPh 2CH 2CH 2PPh 2, (OC) 5Mo PPh 2CH 2CH 2PPh 2, PPh 3, MePh 2P and Me 2PhP with (CH 3) 3SnCH 2I have been studied with 1H NMR spectroscopy. The quaternary phosphonium cations, ▪, formed initially in each reaction, are unstable in chloroform, acetone and methanol but stable in DMSO at ambient temperature. The cations are presumed to interact with I − to give an adduct which dissociates into trimethyltin iodide and an ylid which reacts further to give ▪.