Phosphane Oxide Research Articles

Wasserlösliche Phosphane, III [1]. Wasserlösliche primäre Phosphane mit Ammoniumgruppierungen NR2R' in der Seitenkette -donorfunktionalisierte Amphiphile / Water-Soluble Phosphanes, III [1]. Water-Soluble Primary Phosphanes with Ammonium Groups NR2R' in the Side Chain -Donor-Functionalized Amphiphiles

Primary and secondary aminoalkylphosphanes R2N-(CH2)m-PH2 (R2 = Me2, nBu2, C5H10, C4H8O, 2-(1-Methyl-2-pyrrolidinyl); m = 2, 3, 6, 10, 11; 1-6) or [R2N-(CH2)m]2PH (7, R2 = C5H10; m = 2) are accessible by aminoalkylation of PH3 with ω̃ -chloroalkylamines R2N-(CH2)m-Cl in the superbasic medium DMSO/KOH (DMSO = dimethylsulfoxide). By selective N-quaternization of 1, 2, 4-6 with R'I (R' = Me, CnH2n+1; n = 6-8, 12, 16, 18) in the two-phase system CH2Cl2/H2O novel primary phosphanes [R'R2N-(CH2)m-PH2]+I- (11-16f) with quaternary ammonium groups in the alkyl side chain are obtained. The water solubility of 11-16f decreases with increasing chain length (n) of R′ 11 (R = R' = Me; m = 2) shows a trans conformation at the C2H4 bridge according to an X-ray structural analysis. Protonation of 1, 2, 4, 5 with HCl affords the water-soluble hydrochlorides [HR2N-(CH2)m-PH2]+Cl- (19-22). The cationic primary phosphanes 11-16f are stable towards oxygen. By oxidation of 11 with one or two equivalents of H2O2 the primary phosphane oxide [Me3N-(CH2)2-P(O)H2]+I- (23) or the phosphonous acid [Me3N-(CH2)2- P(O)(OH)H]+I- (23a) are formed. Hofmann degradation of 11 or 16c with KOH yields phosphirane in good yields. Reaction of 1, 2, 4-6 (L) with Fe2(CO)9 at ambient temperature yields stable complexes (CO)4FeL (26-30). Under more rigorous conditions Fe3 clusters (31, 32) with free R2N groups are obtained.

Multifunctional phosphane and phosphane oxide ligands derived from p-tert-butylcalix[4]arene. Synthesis of a large diphosphane with C 2 symmetry and behaving as a cis or trans binding ligand

The calix[4]arene derived di(phosphane oxide) 2 (cone conformation) was obtained in 78% yield by treatment of 1 with 2 equiv NaO tBu followed by reaction with 2 equiv Ph 2P(O)CH 2OTs. When KO tBu was used instead of NaO tBu, the partial cone isomer 2′ was formed. Reaction of 2 with PhSiH 3 in refluxing toluene afforded quantitatively the mixed di(ester)-di(phosphane) ligand 3; crystal data of 3: monoclinic, C2/ c; a = 24.091(7), b = 14.416(4), c = 25.270(8) Å, β = 128.07(2)°, V = 6909.1(5) Å 3, Z = 4 and R F = 5.8%. The molecule which lies on a C 2 axis adopts a distorted cone conformation; the angle formed between the ester substituted phenolic rings is 105(2)° and that between the phosphane substituted rings is 95.0(1)°. The phosphorus lone pairs point towards the exterior of the space defined by the four calixarene substituents, whereas the two ester groups are directed to the interior of this cavity. Ligand 3 reacts with [PtCl 2(PhCN) 2] in THF to yield cis-PtCl 2 · 3 ( 4) in 91% yield. The sequential reaction of [RhCl(1,5-cyclooetadiene)] 2 with 2 equiv AgBF 4 and 2 equiv 3 gave the cationic complex cis-[Rh(1,5- cyclooctadiene) · 3](BF 4) ( 5). Reaction of carbon monoxide with commercial RuCl 3 in boiling 2-ethoxyethanol and subsequent addition of 3 gave cis-cis-trans-P,P-[RuCl 2(CO) 2 · 3] ( 6). Complexes 4-6 display fluxional behaviour in solution. All compounds were characterized by elemental analysis and IR and 1H, 31P, and 13 C NMR spectroscopy.

Stereoselective synthesis of HR 780 a new highly potent HMG-CoA reductase inhibitor

HR 780 ( 1) a new HMG-CoA reductase inhibitor has been synthesized stereoselectively starting from L-malic acid. Wittig olefination employing phosphonium halides, phosphonates and phosphane oxides have been investigated.

Röntgenstrukturanalyse eines Diphosphaadamantans — ein erster Vertreter einer neuen Heterocyclenklasse / X-Ray Structural Analysis of a Diphosphaadamantane — First Derivative of a Novel Class of Heterocycles

X-ray analysis of the intramolecular condensation product of methylene-bis-[bis-(2-oxopropyl)-phosphane oxide] (3) shows heteroadamantane structure. One of the C—P—C-angle seems to be very unusual. A value of only 95.5° was measured.

ChemInform Abstract: Cyclic λ5σ5(σ6)P‐Derivatives of Phosphonic and Phosphinic Acid and the Hypothetical Phosphane Oxide.

AbstractThe trifluorophospholane (I) is converted to the hydro derivatives (III), (V), and (VI) by subsequent fluorine/hydrogen exchange.

ChemInform Abstract: Reactions of Diphenyltrimethylsilylphosphane and Trimethylsilyl Diphenylphosphinite with Fluorinated Ketones.

AbstractThe trifluoromethyl ketones (II) react with the silylphosphane (I) or the silyl phosphinite (IV) to yield the phosphanes (III) or the phosphane oxides (V).

Fragmentation characteristics of trialkylphosphane oxides, R3P(O)

AbstractFragmentation characteristics of trialkylphosphane oxides, R3P(O) (R: Et, n Pr, n Bu) are given and discussed. For phosphane oxides with substitutents R > Et fragmentations within the alkyl groups and ‘conventional’ McLafferty rearrangements are observed. The results of a structure determination for radical cations [C2H7PO]+˙ (m/z 78) and [C4H11PO]+˙ (m/z 106) obtained by collisional activation mass spectrometry are reported.

ChemInform Abstract: Boron Compounds. Part 77. Reactions of Diphenylphosphane Oxide with Organodiboranes(6). Structure of a Zwitterionic ‐POB‐ Compound.

AbstractReaction of the phosphane oxide (I) with the activated borane (II) yields the phosphinooxyborane (III).

ChemInform Abstract: Phosphane Oxides as Intermediates in the Synthesis of Potentially Bioactive Compounds.

AbstractA series of functionalized phosphane oxides such as (III), (V) and (VI) are synthesized as shown in the scheme.

ChemInform Abstract: Dicarboxyphosphane Oxides by Oxidation of Dicarboxyphosphanes with Molecular Oxygen.

AbstractTreatment of the di(benzoyloxy)phosphanes (I) with molecular oxygen in diethylether yields the phosphane oxides (II) which are identical with the products obtained by reacting the dichlorooxyphosphanes (IV) with silver benzoate (III).

Carboxylphosphanes and Carboxyphosphane Chalcogenides

Abstract Low temperature reactions of organo chloro phosphanes with carboxylic acids and their salts allow the preparation of carboxyphosphanes - mixed anhydrides of carboxylic acids with phosphinic acids. These are subject to thermal rearrangement reaction of the Michaelis-Arbusov type. Molecular oxygen converts them into carboxy-phosphorane oxides. These compounds are also obtainable by reacting organochlorophosphane oxides with carboxylates. Their thermal stability is higher than that of the P(III)compounds. Analoguous reactions of P-sulfides and selenides give the corresponding thio and seleno phosphoranes with higher thermal stability. At elevated temperatures a number of rearrangement reactions occur, thus producing phosphane oxides and phosphinic acid phosphinyl alkaryl ester. The reaction products of the following reaction sequences are discusses with regard to their NMR-, IR-, MS-spectra and hydrolytic and thermal properties:

Diphenyl[mono(per)fluoracyI- und aroyl(oxy)]phosphan(oxid)e – neue Synthesen, neue Verbindungen/ Diphenyl[mono(per)fluoroacyl- and aroyl(oxy)]phosphan(oxid)es – New Synthetic Methods, New Compounds

Abstract Diphenylpentafluorobenzoyloxyphosphane 2 a was prepared by reacting diphenylchlorophosphane with sodium pentafluorobenzoate. Reaction of diphenylchlorophosphane with sodium salts of trifluoroacetic acid and of 4-ethoxy-2,3,5,6-tetrafluorobenzoic acid leads to diphenyl trifluoroacetyl phosphane oxide 3b and to diphenyl 4-ethoxy-2,3,5,6-tetrafluoro benzoyl phosphane oxide 3 e. IR data, 19F and 31P {1H } NMR data are given.

ChemInform Abstract: Preparation of Tertiary Phosphane Oxides and Tertiary Alkylidenediphosphane Dioxides in a Two Phase System.

ChemInform Abstract: Preparation of Tertiary Phosphane Oxides and Tertiary Alkylidenediphosphane Dioxides in a Two Phase System.

ChemInform Abstract: Chemistry of Z‐Diphenylphosphoryl Ketene Thioacetals.

AbstractWith the exception of (If) the phosphane oxides (I) can be converted to the title compounds (III) by deprotonation, addition of (IV) and alkylation of the dithiolates; an analogous sequence employing (V) as starting material leads regioselectively to (VII).

Synthese von 2‐Methyl‐4 H ‐1,3‐benzoxazin‐4‐onen und analogen Verbindungen

Synthesis of 2-Methyl-4H-1,3-benzoxazin-4-ones and Related Compounds 4H-1,3-benzoxazin-4-ones 2 are smoothly prepared via (acylimino)phosphoranes 1 by intramolecular condensation analogous to a Wittig reaction. Tert. phosphanes are used for the preparation of the (acylimino)phosphoranes 1 which are converted into the corresponding benzoxazines and tert. phosphane oxides, e.g. 2-methyl-4H-1,3-benzoxazin-4-one (2a) which, in spite of some attempts, has not been obtained before.

Cyclische diazastannylene: XXII. Zur umsetzung eines bis(amino)stannylens mit organylphosphanen, -methylen-phosphoranen, -phosphaniminen, -oxiden und -sulfiden

1,3-Di-t-butyl-2,2-dimethyl-1,3,2,4λ 2-diazasilastannetidin (I) was allowed to react with the phosphanes PEt 3 and PPh 3 as well as with Me 3PCH 2, Ph 3PCH 2, Ph 3PNH, Me 3PO and Et 3PS. While the phosphor ylides and the phosphane oxide interact with I to yield crystalline acid-base adducts, no stable adducts can be isolated with the phosphanes and the phosphane sulfide. The adduct of Ph 3PCH 2 and I crystallizes with one benzene molecule per formula unit in the monoclinic space group P2 1/ c ( a 1188.2(8), b 1438.4(2), c 2169.4(5) pm, β 106.5(4)°). I and Ph 3PCH 2 are linked together by a SnC bond of 240.3(10) pm. The electron transfer from the ylide-carbon to the tin atom can be evaluated from the PC bond length of 174.3(11) pm. The phosphaneimine reacts with I by displacement of the tin atom in I by hydrogen atoms yielding N, N ′-di-t-butyl- Si, Si-dimethylsilazanean and Sn(NPPh 3) 4, and oxidation at the tin atom. 3 molecules of benzene are crystallizing together with one formula unit of Sn(NPPh 3) 4 (monoclinic; C2/ c; a 2470.0(4), b 1643.6(6), c 2382.7(4) pm, β 128.1(3)°). The tin atom is the centre of a tetrahedron of nitrogen atoms, the mean SnN-bond length (197.5 pm) being the shortest so far reported.

Chemistry of 2‐Diphenylphosphoryl Ketene Thioacetals

AbstractCarbanions of diphenylphosphane oxides add to carbon disulfide to give, after alkylation, the title compounds 4. In the reaction with the allylphosphane oxide 5, exclusive γ‐attack is observed to yield dienes 6B. An exploratory study of the reactivity of 4 shows that reduction to thioacetal 7 and hydrolysis to 5‐thiocarboxylates 10 are feasible. Deprotonation of phosphane oxides having a β‐sulfur substituent reveals a high tendency to thiolate elimination to give vinyl sulfides 9, resp. 15. However, reaction of thioester 10a with benzaldehyde indicates that the compounds can be used in Wittig‐Horner olefinations. Ketene thioacetal 4e gives a 1,3 methylthio shift on treatment with acid.

Chemical Bonding in Higher Main Group Elements

AbstractMany concepts used for a qualitative description of chemical bonding that originated in the early days of theoretical chemistry have been vindicated recently by quantum chemical calculations, at least as far as first row elements are concerned. However, many concepts that have been justified for first row elements (Li to Ne) cannot—contrary to widespread belief—be generalized to the higher main group elements. This applies particularly to the concept of hybridization, which should be viewed with considerable caution. The essential difference between the atoms of the first and higher rows is that the cores of the former contain only s‐AOs, whereas the cores of the latter include at least s‐ and p‐AOs. As a consequence, the s and p valence AOs of first row atoms are localized in roughly the same region of space, while the p valence AOs of higher row atoms are much more extended in space. This has the consequence that for the light main group elements both lone‐pair repulsion and isovalent hybridization play a greater role than for the heavy main group elements. Furthermore, this implies that single bonds between first row elements are weak and multiple bonds are strong, whereas for the second or higher row elements single bonds are strong and multiple bonds weak. The “extended valence” (violation of the octet rule) observed in compounds of higher main group elements has very little to do with the availability of d‐AOs but is due rather to the size of these atoms and thus to the reduced steric hindrance between ligands and, to a lesser extent, also to the lower electronegativity of the heavy atoms. A model based on the concept of electron‐rich multicenter bonds is certainly closer to reality than one involving hybrids with the participation of d‐AOs. The XO bonds in phosphane oxides, sulfoxides, oxo acids and related compounds are better formulated as semipolar rather than as true double bonds, even if they behave in some respects like double bonds.—The growing interest of theorists in compounds of higher main group elements parallels new and, in some instances, spectacular results of experimental research on the chemistry of these elements.

Darstellung, Eigenschaften und Reaktivität von 2-, 3- und 4-Chloracyl(diphenyl)phosphanoxiden / Preparation, Properties and Reactivity of 2-, 3- and 4-Chloroacyl(diphenyl)phosphane Oxides

The highly reactive chloroacyl(diphenyl)phosphane oxides RC(O)-P(O)Ph2 (2a-d, g) [R = HCCl2 (a), CCl3 (b), CH3CHCl (c), CH3CCl2 (d), ClCH2CH2 (e), CH3CHClCH2 (f), ClCH2(CH2)2 (g)] are obtained by oxidation of the thermally labile chloroacyl(diphenyl)- phosphanes RC(O)-PPh2 (1a-d, g) with molecular oxygen in ether at low temperatures. While hydrolysis leads to a complete decomposition of 2a-d, g, the oxidation of 1a, c, e-g with oxygen in the presence of HP(O)Ph2 yields the diphosphorylated alcohols RC[P(O)Ph2]2OH (3a, c, e-g). 3e, f can be interpreted as trapping products of the not isolable oxides 2e, f. In tetrachloroethene a partial transformation of 3a into the phosphinate RC[P(O)Ph2][OP(O)Ph2]H can be observed which can be followed 31P{1H}-NMR spectroscopically. In solution the alcohols 3c, e-g decompose to give HP(O)Ph2 and the corresponding phosphane oxides 2c, e-g.

31P solid state nuclear magnetic resonance principal values of the chemical shift tensors of phosphane oxides, phosphane sulphides and phosphane selenides

The principal components of the 31P chemical shift tensor of sixteen phosphane oxides (O=PR 3), phosphane sulphides (S=PR 3) and phosphane selenides (Se=PR 3) have been determined for powder samples using the proton enhanced nuclear induction technique. The chemical shift anisotropy is comparable or larger than the 31P chemical shift difference observed in the liquid state by change of coordination or functionality around the phosphorus. For a given group R, the chemical shift anisotropy is larger for the oxide than for the sulphide or selenide. The electronic distribution around the phosphorus parallels the 31P chemical shift anisotropy. A linear variation of the asymmetry parameter with the departure from C 3 symmetry around the phosphorus is observed.