THE HYDROBORATION OF P-PHENYL-CTERT-BUTYL-C-TRIMETHY LSILOXYMETHYLENE PHOSPHINE

Abstract

P-Phenyl-C-tert.-butyl-C-trimethylsiloxymethylene phosphine (1) has been shown to add catecholboran C₆,H₄,O₂,BH or dicyclohexylboran (C₆,H₁₁)₂BH to give 1:1-adducts with P—B bond which undergo spontaneous β-elimination of trimethylsiloxycatecholboran (4) or trimethylsiloxydicyclohexylboran (8) respectively. The mechanism of reactions is discussed.     

Austauschreaktionen an komplexgebundenen liganden von elementen der IV. hauptgruppe : I. Darstellung und eigenschaften von cyclopentadienyldicarbonyl-alkoxysilyl-eisen-komplexen

The reaction of CpFe(CO)₂SiCl₃ with alcohols yields a partial Cl-OR exchange. By completing the reaction with stoichiometric quantities of the corresponding alcoholate the pure compounds CpFe(CO)₂Si(OR)₃ (R = CH₃, C₂H₅, n-C₃H₇, i-C₃H₇, t-C₄H₉) can be prepared. Excess of alcoholate splits the FeSi bond yielding the [CpFe(CO)₂]^-ion. The compounds are characterised by IR and mass spectra.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XLIV. Tetrakis(alkoxycarbonylmethyl)titan-Verbindungen

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XLIII. Tetrakis(alkoxycarbonylmethyl)titanium Compounds Organotitanium(IV) compounds of the type (ROCOCH₂)₄Ti (R ? C₂H₅, i-C₃H₇, t-C₄H₉, C₆H₅, C₆H₅CH₂) were obtained by reactions of ROCOCH₂Li derivatives with TiCl₄ at low temperature. The compounds which decompose only above 90°C were characterized by the hydrolysis products, anaerobic reactions with iodine, and the i.r. spectra. The bond conditions are discussed.     

Dichloromethyleneamides of dialkyl phosphates

Summary Dichloromethyleneamide dialkyl phosphates (AlkO)₂P(O)N=CCl₂ (alkyl: C₂H₅,C₃H₇, i-C₃H₇, C₄H₉, i-C₄H₉) were obtained by reaction between chlorine and the corresponding isothiocyanatophosphate esters. The dichlorides obtained reacted vigorously with amines, alcohols, and alcoholates.Translated from Izvestiya Akademii Nauk SSR, Seriya Khimicheskaya, No. 5, pp. 932–933, May, 1964     

Darstellung neuer Alkylaminofluorsilane

Preparation of New Alkylaminofluorosilanes Aminofluorosilanes of the composition RSiF₂NR′R″ (R = H, CH₃, C₂H₃, C₆H₅; R′ = Si(CH₃)₃; R″ = C(CH₃)₃; R′ = R″ = i-C₃H₇), as well as C₆H₅SiF₂N[C(CH₃)₂CH₂]₂CH₂ are obtained by the reaction of fluorosilanes with the lithium salts of the corresponding amines in a molar ratio 1:1. The further reaction of these compounds with the lithium salts of alkylamines and anilin leads to the formation of the diaminofluorosilanes RSiFNR′R″NHR? (R? = C(CH₃)₃, i-C₃H₇, C₆H₅). The ¹H, ¹⁹F, ²⁹Si n.m.r. and mass spectra of the above mentioned compounds are reported.     

Triphenyltelluroniumcarbamate und -dithiocarbamate

Triphenyltelluronium Carbamates and Dithiocarbamates Compounds of the type (C₆H₅)₃TeS₂CNR₂ with R ? CH₃, i-C₃H₇, C₆H₅ and (C₆H₅)₃TeO₂CN(CH₃)₂ are obtained by reaction of triphenyltelluronium chloride with sodium dithiocarbamates or ammonium carbamate. In the same way ethylene- bis(N,N′-methyldithiocarbamicacid-S,S′-λ⁴-triphenyltellurylester) was synthesized. (C₆H₅)₃TeO₂CN(CH₃)₂ reacts with CS₂ to give (C₆H₅)₃TeS₂CN(CH₃)₂.     

Kinetics and Mechanism of the Reaction of Chloroplatinum(II) Complexes with Alkyl Radicals

The reaction between certain platinum(II) complexes and alky radicals produces an unstable organoplatinum(III) intermediate, {Pt^III -R}. The kinetics of this step were evaluated by laser flash photolysis with ABTS² (2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) ion) and TMPD (tetramethylphenylenediamine) as kinetic probes. The rate constants for PtCl₄^2? are: k_Pt/10⁸ L mol^?1 s^?1 = 5.2, 2.8 and 0.27 for CH_3, C₂H₅, and CH₂Cl in aqueous solution at pH 1. Those with cis-Pt(NH₃)₂Cl₂ are somewhat smaller, and those for Pt(NH₃)₄²⁺ too small to measure will) this technique. The product analysis indicates that the decomposition of organoplatinum takes place by hydrolysis and (for R = C₂H₅ only) by β-elimination, The kinetic isotope effect on die β-elimination of DCH₂CH₂PtC₄,^2? is k_H/k_D = 1.2. The β-elimination step produces a Pt^III-hydride that releases hydrogen gas and forms {Pt_III-OH}. The short-lived Pt(III) intermediate may disproportionate or oxidize the Co^II complex that is produced in the radical-generating step.     

Kinetics and mechanism of acid hydrolysis of peroxyketals

The kinetics of hydrolysis of aliphatic ketone di-tert-butylperoxyketals R¹R²C=O, R¹, R²=CH₃, CH₃; CH₃, C₂H₅; CH₃, n-C₃H₇; CH₃, n-C₆H₁₃; CH₃, i-C₅H₁₀; CH₃, i-C₄H₉; C₂H₅, i-C₃H₇; n-C₄H₉, n-C₄H₉; CH₃, C₆H₅-CH₂, in dioxane in the presence of H₂SO₄ were investigated by IR spectroscopy. It was found that the reaction is reversible and takes place according to the equation R¹R²C· (OOC(CH₃)₃)₂ + H₂O;_H+ R¹R²C=O + 2HOOC(CH₃)₃. The proposed mechanism of hydrolysis includes the fast, quasiequilibrium formation of protonated peroxyketal and subsequent formation of the alkylperoxycarbenium ion. A three-parameter correlation equation is proposed for describing the initial rates of hydrolysis of R¹R²C(oo-t-Bu)₂ peroxyketals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2501–2506, November, 1990.     

Systematische untersuchungen über das verhalten von organozinn-verbindungen gegenüber flüssigem schwefeldioxid : I. Reaktionen von tetraalkylstannanen mit flüssigem SO2

The SO₂ insertion into teraalkyltin compounds, R₄Sn (R = CH₃, C₂H₅, n-C₃H₇, i-C₃H₇, n-C₄H₉), was investigated depending on the presence of water, reaction temperature and reaction time. According to eqns. (1)–(5), the reaction products R₃SnO₂SR, R₂Sn(O₂SR)₂, (R₃Sn)₂SO₄, R₂SnSO₄ and R₂SnSO₃ were isolated. Especially; at low temperatures (<0°) the following order of decreasing reactivity of the teraorganostannanes toward SO₂ is established: R = C₂H₅ > CH₃ > n-C₃H₇ > n-C₄H₉ > i-C₃H₇     

Diorgano-tellur-bis-(dialkylcarbamate) und -(dithiocarbamate)

Diorganyltellurium Bis-(dialkylcarbamates) and -(dithiocarbamates) Compounds of the type R₂Te(X₂CNR′₂)₂, with R ? C₆H₅, CH₃; R′ ? CH₃, C₂H₅, i-C₃H₇, c-C₆H₁₁, C₆H₅, and X ? S, are obtained by reaction of dimethyltellurium with tetraorganyl-thiuram-disulfides. Dimethyltellurium diiodide or diphenyltellurium dichloride react with sodium dithiocarbamates or with in situ prepared ammonium dithiocarbamates. Some compounds can be synthesized by reaction of diphenyltellurium oxide with amine in solutions of carbon disulfide. The synthesis of diphenyltellurium- and dimethyltellurium bis-(dimethylcarbamates) results from the interaction of diorganyltellurium diethanolate with dimethylammonium dimethylcarbamate. Decomposition reactions of the compounds in solid and solution are studied ¹H-NMR, ¹³C-NMR, and mass spectroscopically. Diorganyltellurium diethylen-bis-(N,N′-dimethyldithiocarbamates) are obtained by reaction of dimethyltellurium diiodide or diphenyltellurium dichloride and sodium ethylen-bis-(N,N′-dimethyldithiocarbamate) as polymeric products.     

DIORGANOTELLURBIS (ALKYLXANTHOGENATE), TEIL II

Abstract

Diphenyltelluriumbis(alkylxanthates) as well as telluracyclopentane-1,1-bis(alkylxanthates) of the general formula R₂Te(S₂COR')₂ and C_4H8Te(S₂COR′)₂ (R = C₆H₅ and R′ = CH₃, C₂H₅, i-C₃H₇) are obtained by reaction of diphenyltellurium-dichloride or telluracyclopentane-1,-diiodide with sodium-xanthates. The insertion of CS₂ into the corresponding organotelluriumbis-alkoxydes is only successful in the case of the cyclic compound. Diphenyltelluriumbis-alkoxydes react with decomposition. This decomposition in substance and in solution is investigated.

Man erhält Diphenyltellurbis(alkylxanthogenate), sowie Telluracyclopentan-1,1-bis(alkylxanthogenate) der Formel R₂Te(S₂COR′)₂ bzw. C₄H₈Te(S₂COR′)₂ mit R = C₆H₅, R′ = CH₃, C₂H₅, i-C₃H₇, durch Umsetzung von Diphenyltellurdichlorid bzw. Telluracyclopentan-1,1-diiodid mit den entsprechenden Natriumxanthogenaten. Prinzipiell führt auch die Einschiebung von CS₂ in Telluracyclopentan-1,1-bisalkoholate zu den entsprechenden Xanthogenatverbindungen. Bei der Umsetzung von CS₂ mit Diphenyltellurbis(alkoholaten) konnten nur die, für diese Xanthogenatverbindungen charakteristischen Zersetzungsprodukte isoliert werden. In diesem Zusammenhang wurde die thermische und solvensabhängige Zersetzung untersucht.     

Reactions of metal carbonyl derivatives : XI. Tertiary phosphine,phosphite and stibine and ditertiaryphosphine and arsine derivatives of bis(μ-phenyl- sulphidotricarbonyliron)

The ditertiary phosphines (C₆H₅)₂P(CH₂)_nP(C₆H₅)₂ (n = 1 and 2), cis(C₆H₅)₂PC₂H₂P(C₆H₅)₂ and (C₆H₅)₂PN(C₂H₅)P(C₆H₅₂ and the ditertiary arsines (C₆H₅)₂As(CH₂)_nAs(C₆H₅)2 (_n = 1 and 2) react with [Fe(CO)₃SC₆H₅]₂ to give a wide range of products, the nature of which depends on the reaction conditions and the ligand involved. Examples of the different types of comp isolated include, (i) Fe₂(CO)₅[(C₆H₅)₂PCH₂P(C₆H₅)₂](SC₆H₅)₂, in which the ligand acts as a monodentate, (ii) {[Fe(CO)₂SC₆H₅]₂[(C₆H₅)₂PC₂H₄P(C₆H₅)₂]}₂, in which two [Fe(CO)₂SC₆H₅]₂ moieties are bridged by two diphosphine ligands, (iii) [Fe(CO)₂SC₆H₅]₂[(C₆H₅)₂PN(C₂H₅)P(C₆H₅)₂], in which the ligand bridges the two iron atoms, and (iv) Fe(CO)₃(SC₆H₅)₂Fe(CO)[(C₆H₅)₂PC₂H₂P(C₆H₅)₂], which contains the ligand chelated to a single iron atom. The tertiary phosphines PR₃ (R=C₂H₅ and C₆H₅), phosphites P(OR′)₃(R′ = CH₃, C₂H₅, i-C₃H₇ and C₆H₅) and the stibine Sb(C₆H₅)₃ bring about mono-, bis- or tris-substitution in [Fe(CO)₃SC₆H₅]₂ depending on the reaction conditions and the ligand involved. Whereas in solution [Fe(CO)₂L(SC₆H₅)]₂ [L = PR₃ (R = C₂H₅ and C₆H₅), P(OC₆H₅)₃ and Sb(C₆H₅)₃] exist as a single isomer, [Fe(CO)₂L′(SC₆H₅)]₂ [L′=P(OR′)₃ (R'=CH₃, C₂H₅ and i-C₃H₇)] occur as a mixture of isomers.     

Diiod(methylthio)gallan. Darstellung und reaktivität

Different synthetic routes for the preparation of diiodo(methylthio)gallane are given. Some reactions of this compound with Lewis bases, such as O(CH₃)₂, S(CH₃)₂, S₂(CH₃)₂, N(CH₃)₃, P(CH₃)₃, and other compounds, such as CH₃I, CH₃OH, C₂H₅OH, C₂H₅SH, i-C₃H₇SH, and C₂H₅SeH are investigated. Spectra and some physical and chemical properties of the new compounds are reported. The structure of diiodo(methylthio)gallane is discussed in view of some interesting differences of this molecule in solution and in crystal form.     

Trivalent-pentavalente Phosphorverbindungen/Phosphazene. II. Synthese N-silylierter Phosphinimine

Trivalent-Pentavalent Phosphorus Compounds/Phosphazenes. II. Synthesis of N-silylated Phosphinimines N-silylated phosphinimines (RO)₃P?N? Si(CH₃)₃ (R = ? C₂H₅, ? C₂H₂F₃, i-C₃H₇, n-C₄H₉) and (R₂N)₃P?N? Si(CH₃)₃ (R = ? C₂H₅) have been prepared by reaction of trialkyl phosphites P(OR)₃ and Tris-(diethylamino)-phosphine P(NR₂)₃ with trimethylsilyl azide. The products were identified by analysis, IR-, ¹H-, ¹⁹F-, ²⁹Si-, ³¹P-n.m.r. and mass spectroscopy.     

Partnering a Three-Coordinate Gallium Cation with a Hydroborate Counter-Ion for the Catalytic Hydrosilylation of CO2

A novel β-diketiminate stabilized gallium hydride, (^DippL)Ga(Ad)H (where ( ^Dipp L)={HC(MeCDippN)₂}, Dipp=2,6-diisopropylphenyl and Ad=1-adamantyl), has been synthesized and shown to undergo insertion of carbon dioxide into the Ga−H bond under mild conditions. In this case, treatment of the resulting κ¹-formate complex with triethylsilane does not lead to regeneration of the hydride precursor. However, when combined with B(C₆F₅)₃, (^DippL)Ga(Ad)H catalyses the reductive hydrosilylation of CO₂. Under stoichiometric conditions, the addition of one equivalent of B(C₆F₅)₃ to (^DippL)Ga(Ad)H leads to the formation of a 3-coordinate cationic gallane complex, partnered with a hydroborate anion, [(^DippL)Ga(Ad)][HB(C₆F₅)₃]. This complex rapidly hydrometallates carbon dioxide and catalyses the selective reduction of CO₂ to the formaldehyde oxidation level at 60 °C in the presence of Et₃SiH (yielding H₂C(OSiEt₃)₂). When catalysis is undertaken in the presence of excess B(C₆F₅)₃, appreciable enhancement of activity is observed, with a corresponding reduction in selectivity: the product distribution includes H₂C(OSiEt₃)₂, CH₄ and O(SiEt₃)₂. While this system represents proof-of-concept in CO₂ hydrosilylation by a gallium hydride system, the TOF values obtained are relatively modest (max. 10 h⁻¹). This is attributed to the strength of binding of the formatoborate anion to the gallium centre in the catalytic intermediate (^DippL)Ga(Ad){OC(H)OB(C₆F₅)₃}, and the correspondingly slow rate of the turnover-limiting hydrosilylation step. In turn, this strength of binding can be related to the relatively high Lewis acidity measured for the [(^DippL)Ga(Ad)]⁺ cation (AN=69.8).     

The direct synthesis of magnesium amides and the crystal structure of an unusual magnesium tert-butylamide

The magnesium amides Mg(NHi-C₃H₇)₂; Mg(N(C₂H₅)₂)₂ and Mg(NC₅H₁₀)₂ have been prepared by direct synthesis from magnesium and i-C₃H₇NH₂, (C₂H₅)₂NH or C₅H₁₀NH, respectively, at high temperature and under a pressure of hydrogen. When an excess of Mg was used MgH₂ was isolated, suggesting that magnesium hydride is an intermediate in this reaction.t-C₄H₉NH₂ gave two crystalline products, NMg₆(NHt-C₄H₉)₉ (I) and an insoluble material, probably (MgNR)_x. The structure of I was determined by X-ray crystallography.     

The chemical consequences of the N14(n,p)C14 reaction in triethylsilylmethylamine

Summary After neutron irradiation of triethylsilylmethylamine the carbon-14 formed by the N¹⁴(n,p)C¹⁴ reaction proves to be bound as (C₂H₅)₄Si and (C₂H₅)₃SiNHCH₃ to the extent of 1.31%, as (C₂H₅)₃SiNHC₂H₅ and (C₂H_{5 3}SiN(CH_{3 2} to the extent of 4.48%, and as n-C₃H₇(C₂H₅)₂SiNHCH₃ and i-C₃H₇(C₂H₅)₂SiNHCH₃ to the extent of 3.43%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimisheskaya, No. 7, pp. 1266–1267, July, 1965     

Synthesis and properties of dicyclopentadienyltantalum hydride olefin compounds

Reactions of Cp₂TaCl₂ with RMgCl (R = n-C₃H₇, i-C₃H₇, n-C₄H₉, s-C₄H₉, n-C₅H₁₁ and C₅H₉) give tantalum hydride π-olefin complexes Cp₂Ta(H)L (L = C₃H₆, C₄H₈, C₅H₁₀ and C₅H₈). Two isomers of Cp₂Ta(H)C₃H₆ were obtained. The complexes are useful starting materials for the synthesis of other tantalum hydride species, e.g. Cp₂Ta(H)PEt₃ and Cp₂TaH₃.     

Reactivity of digallane toward nitrogen-containing compounds

The reactions of [LGa–GaL] (L = dpp-bian = 1,2-bis[(2,6-di-isopropylphenyl)imino]acenaphthene) with ammonia and pyrrolidine in toluene lead to the formation of adducts [L(NH₃)Ga–Ga(NH₃)L], [L(HNC₄H₈)Ga–GaL] and [L(HNC₄H₈)Ga–Ga(HNC₄H₈)L], respectively. In contrast, the reaction between crystalline digallane and an excess of pyrrolidine leads to the formation of compound [LGa(NC₄H₈)(HNC₄H₈)]. The complex [LGa(C₅H₅N)(μ-O)Ga(C₅H₅N)L] was obtain from reaction of digallane with N₂O in the presence of pyridine.     

Chlor(methyl)(organylthio)gallane,die ersten vertreter dieser gallium(III)-verbindungen

The reactions between dichloromethylgallane and the silyl sulfides (CH₃)₃SiSR (R = CH₃, C₂H₅, n-C₃H₇, i-C₃H₇, Ph and CH₂Ph) in benzene result in the formation of the hitherto unknown, extremely moisture-sensitive chloro(methyl)(organylthio)gallanes. Reactions of these thiogallanes with the donor compounds N(CH₃)₃ and O(CH₃)₂ are reported. Spectra as well as some physical and chemical properties of the new compounds are given.