Phosphine Imides Research Articles

Transformation of CO2 and isocyanates mediated by N-borane-substituted cyclic phosphine imides (BCPIs) via λ5-oxazaphosphetanes.

We herein report reliable evidence that λ5-oxazaphosphetane species are a key intermediate in the transformation of CO2 and isocyanates through their reaction with N-borane-substituted cyclic phosphine imides (BCPIs). We have isolated and fully characterized several λ5-oxazaphosphetane species prepared via formal [2 + 2] cycloaddition reactions between BCPIs and CO2 or isocyanates. The transformation of these λ5-oxazaphosphetanes via retro-ring opening reaction afforded an isocyanate and a carbodiimide from the CO2- and isocyanate-derived λ5-oxazaphosphetanes.

N-Borane-Substituted Cyclic Phosphine Imides (BCPIs)

Abstract Phosphine imides are ubiquitous nucleophiles/Lewis bases in modern organic chemistry. The introduction of unexplored substituents on the phosphine imidoyl nitrogen and/or phosphorus atoms should facilitate the discovery of unprecedented utility for phosphine imides. Herein, we have designed and prepared a novel class of phosphine imides known as N-borane-substituted cyclic phosphine imides (BCPIs). Experimental and theoretical analyses of the electronic structure of BCPIs demonstrate the existence of substantial negative hyperconjugation between the nitrogen and the phosphorus atoms. Given a characteristic nucleophilic/Lewis basic reactivity of BCPIs, we demonstrate the spontaneous heterolysis of a B–Cl bond in a BCPI-coordinated chloroborane, suggesting that such process is a plausible key step in the Lewis acid-promoted generation of borenium species from chloroboranes, although it has been previously considered unlikely.

Covalent Functionalization of GaP(110) Surfaces via a Staudinger-Type Reaction with Perfluorophenyl Azide

Despite the markedly low chemical reactivity of the nonpolar (110) surfaces of III–V semiconductors, the covalent functionalization of GaP(110) surfaces with perfluorophenyl azide (PFPA) molecules by a Staudinger-type reaction occurs only slightly above room temperature (325 K). Scanning tunneling microscopy observations, combined with density functional theory calculations, support the formation of stable, covalent perfluorophenyl nitride (PFPN) molecule–surface bonds, which can be described as Lewis acidic Ga-stabilized phosphine imides. π–π stacking between aromatic, electron-deficient PFPN units results in compact, commensurate 2D molecular assembly at the surface. PFPA deposition on GaP(110) at room temperature with no additional annealing leads to an intermediate phase consistent with an alternating 1D array of physisorbed and chemisorbed molecular units. This work provides a new route for covalently bonding molecular linkages to the (110) surfaces of III–V semiconductors.

ChemInform Abstract: Synthesis of a Phosphine Imide Bearing a Hydrosilane Moiety, and Its Water‐Driven Reduction to a Phosphine.

AbstractThree novel phosphine imides (III) and (V) are synthesized by lithiation of imide (I) followed by treatment with corresponding chlorosilane.

Control of reactivity of phosphine imides by intramolecular coordination with an organoboryl group

Phosphine imides with a boryl substituent 3–5 were synthesized. Their structures were revealed to have a tetracoordinated boron and a phosphorus atom, featuring the N–B coordination by X-ray crystallographic analysis and NMR spectroscopy. The phosphine imide moiety was persistent to hydrolysis, methylation, and the aza-Wittig reaction. The N–B coordination remained intact upon treating with pyridine or fluoride ion. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:429–434, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21033

Bis(phosphine Imide)s: Easily Tunable Organic Electron Donors

[graph: see text] The electrochemical, structural, and spectroscopic properties of bis(phosphine imide)s have been investigated. p-Phenylenebis(phosphine imide)s Ar3PNC6H4NPAr3 (1a-d) have two reversible single-electron oxidations. The first oxidation potentials can be varied from -0.05 to 0.15 V (versus SCE) by modification of the substituents on phosphorus (Ar). Electron-donating substituents lower the oxidation potential, while electron-withdrawing substituents increase the oxidation potential. The difference between the first and second oxidation potential (deltaE, 0.41-0.50) and the electronic coupling (Hab, 1.1 eV) are similar for 1a-d. Computational (DFT) and UV-visible-NIR spectroscopic investigations of 1a-d suggest that the first oxidation leads to a delocalized radical cation 1a*+ while the second oxidation leads to a quinonoidal dicationic state 1a2+. The aromatic linker between phosphine imides has also been modified. Upon oxidation, N,N'-4,4'-biphenylene(bis(triphenyl)phosphine imide) (3) forms radical cationic and a dicationic species similar to 1a-d. While deltaE (0.18 V) and Hab (0.63 eV) are smaller, suggesting weaker electronic communication between the two P=N units in the radical cationic state, the presence of NIR absorptions with vibrational fine structure (768, 861, and 983 nm) supports the formation of delocalized radical cation for 3*+.

A density functional study of the bonding in tertiary phosphine chalcogenides and related molecules

The nature of the phosphorus–tellurium bond in tertiary phosphine tellurides is not well understood. There is also controversy over the nature of multiple bonding in the lighter chalcogenides and the related ylides and imides. Density functional theory (DFT) was used to investigate the interactions in the molecule, Me3PE (E = O, S, Se, Te, BH3, CH2, NH). The calculated PE bond energies and orbital populations reveal contributions from both σ donation from the phosphine and π back-donation to the phosphine in all of the above cases. Down the group from oxygen to tellurium, the PE bond weakens from 544 kJ mol−1 to 184 kJ mol−1, but multiple bonding becomes more significant with respect to the single bond. For E = BH3, the PB bond energy is 166 kJ mol−1. Trimethylphosphine ylide was found to have a π-bond order of 0.5, while that of trimethylphosphine imine is 0.6. For comparison, the oxides of trimethylamine and trimethylarsine were also calculated to examine the pnictogen–oxygen bond; Me3N does not participate in multiple bonding with oxygen, while the π-bond orders for Me3PO and Me3AsO were calculated as 0.7 and 0.6, respectively. Key words: phosphine chalcogenides, phosphine ylides, phosphine imides, DFT calculations

Mitsunobu-type alkylation of p-toluenesulfonamide. A convenient new route to primary and secondary amines

p-Toluenesulfonamide, which is known to form phosphine imides under Mitsunobu conditions, was shown to be alkylated in the presence of cyanomethylenetributylphsphorane to give N-substituted sulfonamides in excellent yields. The reaction can be applied to the synthesis of symmetrical and unsymmetrical N, N-disubstituted amides. When coupled with the desulfurization reactions, the reaction provides a new versatile synthetic route to primary and secondary amines from ammonia.

Simple preparations of new monomeric trihalogenophosphine imides

The oxidation of halogeno(2,4,6-tri-tert-butylphenylimino)phosphines [(2,4,6-But3C6H2)NPX, X = Cl, Br or I] with dihalogens (Cl2, Br2 or I2) resulted in the formation of trihalogeno(N-2,4,6-tri-tert-butylphenyl)phosphine imides. The imides (2,4,6-But3C6H2)NPCl3 and (2,4,6-But3C6H2)NPBr3 were obtained quantitatively from the corresponding halogenoiminophosphine with PhlCl2 and Br2, respectively, and were crystallographically characterized [(2,4,6-But3C6H2)NPCl3; Cm, a= 11.960(3), b= 14.696(2), c= 5.954(2)A, β= 97.71 (2)°, Z= 2, R= 0.036, R′= 0.047; (2,4,6-But3C6H2)NPBr3; P2,/c, a= 18.841(8), b= 9.480(4), c= 12.186(5)A, β= 98.00(3)°, Z= 4, R= 0.068, R′= 0.074]. Reactions involving a halogenoiminophosphine and a different halogen are accompanied by halide exchange and give mixtures of products, most of which can be assigned and include the mixed trihalides, (2,4,6-But3C6H2)NPX2X′. No reaction is observed between (2,4,6-But3C6H2)NPI and I2, but one iodo derivative has been isolated and characterized spectroscopically and by X-ray crystallography as (2,4,6-But3C6H2)NPCl2I2 which is formed in the disproportionation reaction of (2,4,6-But3C6H2)NPCl and I2. The trihalides are monomeric in the solid state and exhibit extremely short N–P bonds with large angles at the nitrogen centres.

Facile route for the synthesis of triosmium and triruthenium isocyanide complexes

The osmium isocyanide complexes Os 3(CO) 11(CNR) ( 1a, R  Pr; 1b, R  iPr; 1c, R  CH 2Ph; 1d R  Ph) are synthesized in high yields by reaction of Os 3(CO) 12 with phosphine imides via a deoxygenation mechanism. These complexes react with an additional equivalent of Ph 3PNR to yield the diisocyanide complexes Os 3(CO) 10(CNR) 2 ( 2a, R  Pr; 2b, R  iPr; 2c, R  CH 2 Ph; 2d, R  Ph). The reaction of Os 3(CO) 10(CNCH 2Ph) 2 with excess Ph 3PNPr or Ph 3PNCH 2Ph in refluxing benzene gives Os 3(CO) 9(CNCH 2Ph) 2(CNR) ( 3a, R  Pr; 3b, R  CH 2Ph). The ruthenium isocyanide derivatives Ru 3(CO) 11(CNR) ( 4a, R  Pr; 4b, R  iPr, 4c, R  CH 2Ph; 4d, R  Ph) are also prepared by reaction of Ru 3(CO) 12 with phosphine imide. It was observed that geometrical and electronic characteristics of the imide play key roles in controlling the rate of the reaction.

POLYSULFONYLAMINE: TEIL XXVIII.1REAKTION VON N-CHLORDIMESYLAMIN MIT EINIGEN PHOSPHOR(III)-VERBINDUNGEN. RÖNTGENSTRUKTURANALYSEN VON [iPr3PCl]+−N(SO2Me)2. CH2Cl2UND (PhO)3P[dbnd]NSO2Me

Abstract N-Chloro-dimesylamine ClN(SO2Me)2 (1) reacts with the appropriate triorganophosphines to give the ionic chloro(triorgano)phosphonium dimesylamides R3PCI+ −N(SO2Me)2 [R = iPr (2a), nBu (2b), Ph (2c)]. The reaction of 1 with (MeO)3P affords (MeO)2P(O)Cl and MeN(SO2Me)2; its reaction with (PhO)3P or PCl3 leads to elimination of MeSO2Cl and formation of the phosphine imides Y3P[dbnd]NSO2Me [Y = PhO (3a), Cl (3b)]. The (1/1) dichloromethane solvate of 2a crystallizes in the monoclinic space group P21/c with a = 1735.6(7), b = 841.1(4), c = 1658.4(7) pm, β = 118.34(3)°, U = 2.1309(16) nm3, Z = 4. The crystal lattice consists of discrete iPr3PCl+ cations (P[sbnd]Cl 199.4 pm, bond angles at P 105.7–117.5°), (MeSO2)2N− anions and CH2Cl2 molecules apparently hydrogen-bonded to oxygen atoms of the anions. 3a crystallizes in the monoclinic space group P21/c with a = 974.7(3), b = 2052.3(6), c = 959.5(3) pm, β = 98.820(14)°, U = 1.8967(10) nm3, Z = 4. The dimensions of the molecule (P[sbnd]N 154.4, N[sbnd]S 1...

ChemInform Abstract: Triaryl (Dialkoxyphosphorylimido)phosphates: Synthesis and Properties.

AbstractThe phosphites or phosphines (I) are coupled with the azidophosphates (II) to give the phosphorylimidophosphates (IIIa) ‐ (IIIc) or the phosphine imides (IIId) ‐ (IIIf).

ChemInform Abstract: Functionalized Phosphine Imides. Diastereoselective Synthesis of β‐Hydroxyphosphorylated Derivatives.

AbstractThe phosphine imides (I) are converted to the 2‐hydroxyalkylphosphine oxides (IV) by metalation and coupling with the aldehydes (II), followed by hydrolysis.

ChemInform Abstract: Organo‐Arsenic Compounds with an As=N Bond. Part 12. Reaction of Triarylarsine Imides with Alcohols, Phenols, and Their Thioanalogues. Properties of Oxy‐ and Mercaptoarsoranes.

AbstractIn contrast to related phosphine imides, the arsine imides (I) react with the phenols, propyl mercaptan, or thiophenol (II) to give the arsoranes (III).

ChemInform Abstract: Triorganophosphine Bromodimethylsilylimides.

AbstractThe phosphine imides (I) react with dimethyldibromosilane (II) to form either the dimeric compounds (IIIa) or the monomeric phosphine silylimides (IVb).

ChemInform Abstract: Tandem Aza‐Wittig Reaction/Electrocyclic Ring‐Closure ‐ a Facile Entry to the Synthesis of Fused Pyrimidines: Preparation of Pyrazolo(3,4‐d)‐ and 1,2,3‐Triazolo(4,5‐d)pyrimidine Derivatives.

AbstractThe iminopyrazolyl azides (III), prepared from the chloroformylpyrazole (I), react with triphenylphosphine (IV) to form the phosphine imides (V).

ChemInform Abstract: A Simple Synthesis of the First 1,2λ5‐Benzazaphosphinine Ring.

AbstractMethyl o‐azidobenzoate (I) is coupled with the phosphanes (II) to produce the phosphine imides (III) which are treated with potassium hydride.

ChemInform Abstract: A New Route to Cyclic Urea Derivatives of Sugars via Phosphine Imides.

AbstractThe glycosyl azides (I) react with triphenylphosphine (II) to form the phosphine imides (III) which are converted to the phosphonium perchlorates (IV).

Functionalized Phosphine Imides. Diastereoselective Synthesis of β-Hydroxyphosphorylated Derivatives

The phosphine imides (I) are converted to the 2-hydroxyalkylphosphine oxides (IV) by metalation and coupling with the aldehydes (II), followed by hydrolysis.

ChemInform Abstract: New Types of Triphenylphosphine Acylimides.

AbstractThe phosphine imides (I) react with the dichlorides (II) to produce the bis‐ (III) or monophosphoranylidenamino compounds (IV) depending on the molar ratio.