Acyl- und Alkylidenphosphane. XVI. (Dimethylaminomethyliden)- und (Diphenylmethyliden)phosphane

Acyl- and Alkylidenephosphines. XVI. (Dimethylaminomethylidene)- and (Diphenylmethylidene) phosphines Alkyl- or arylbis(trimethylsilyl)phosphines 1 (R = mesityl, C₉H₁₁ a ; (CH₃)₃C b ; C₆H₅ c ; CH₃ d ) react only very slowly with dimethylformamide 2 and benzophenone 4. After repeated addition of small amounts of solid sodium hydroxide, however, the reaction-time is shortened from several months to a few days. The reactions between 1 a or 1 b and 2 yield the (dimethylaminomethylidene)phosphines 3 a and 3 b ; from 1 a and 4 mesityl-(diphenylmethylidene)phosphine 5 a is obtained. The formation of the thermally labile phosphines 3 d and 5 c is proved by NMR spectroscopy; these compounds dimerize very fast to give 2,4-bis(dimethylamino)-1,3-dimethyl- 10 d and 1,2,2,3,4, 4-hexaphenyl-1,3-diphosphetane 15 c. Similarly the lithium trimethylsilylphosphides 6 a , 6 c and 6 e (R = (CH₃)₃Si) react with 2 or 4 to form 3 a and 5 c as well as (diphenylmethylidene)-trimethyl-silylphosphine 5 e .     

Reaktionen von 1,2-Bis(trimethylsilyl)iminen mit Selen-und Tellur-halogeniden

Reactions of 1,2-Bis(trimethylsilyl)imines with Selenium and Tellurium Halogenides The reactions of benzil-bis(trimethylsily)imine and phenanthrene-9,10-bis(trimethylsilyl)imine with SeOCl₂, SeCl₄ and TeCl₄ are described.     

1,2- and 1,3-diphosphetanes from alkylidenephosphines

Abstract

Alkyl- or arylbis(trimethylsilyl)phosphines as well as tris(trimethylsilyl)phosphine and the corresponding arsines react with acyl chlorides to give [1-(trimethylsiloxy)alkylidene]phosphines 1 and -arsines 2; most of their 2,2-dimethylpropylidene derivatives are thermally stable at room temperature. With the same class of phosphines as starting compounds and carbon disulfide [bis(trimethylsilylsulfano)methylidene]phosphines 3 are formed, whereas [(dialkylamino)methylidene]-4 and [diarylmethylidene]phosphines 5 or the corresponding arsines 6 and 7 can be obtained from acyl amides or ketones.¹     

Pseudohalogenverbindungen. Darstellung und Reaktionsverhalten von Alkyl- und Arylammoniumdicyanamiden, -tricyammethaniden und -dicyanmethanidoaceta-ten [RNH3]X (X  N(CN)2, C(CN)3, C(CN)2C(O)CH3)

Pseudohalogen Compounds. Synthesis and Reactivity of Alkyl- and Arylammonium Dicyanamides, Tricyanmethanides, and Dicyanmethanidoacetates [RNH₃]X (X ? N(CN)₂, C(CN)₃, C(CN)₂C(O)CH₃) The syntheses of alkyl- and arylammonium dicyanamides, tricyanmethanido, and dicyanmethanido-acetates are reported. At higher temperatures the synthesized dicyanamides and tricyanmethanides are reacting to the corresponding cyanoguanidine and to 1,1-diamino-2,2-dicyano-ethene derivatives, respectively. The new compounds are characterized on the basis of their i.r. spectra and elemental analyses.     

Darstellung und Umlagerung von silylsubstituierten Ketoenolen

4-Hydroxycoumarin and dimedone, two carbonyl compounds, which are known to form enoles readily, are treated with trimethylchlorosilane in the presence of triethylamine to give their hitherto unknown trimethylsilyl derivatives.A solvent-dependent, reversible migration of the trimethylsilyl group was observed by means of¹H-NMR-spectroscopy.     

Trimethylsilylverbindungen der Vb-Elemente. I Synthese und Eigenschaften von Trimethylsilylarsanen

Trimethylsilyl Derivatives of Vb-Elements. I. Syntheses and Properties of Trimethylsilylarsanes Chlorotrimethylsilane and ?Na₃As/K₃As”? prepared from a sodium potassium alloy and arsenic powder in dimethoxyethane form tris(trimethylsilyl)arsane 4 in 80 to 90percent; yield. 4 reacts with methyllithium in THF or dimethoxyethane to lithiumbis(trimethylsilyl)arsenide 5 , which crystallizes with two molecules THF – 5a – or one molecule dimethoxyethane – 5b – per formula unit. The latter adduct is dimeric in benzene. In the reaction of 5 with primary and secondary alkyl halides methyl- 1a , ethyl- 1b , isopropyl- 1c , benzyl- 1d , diphenylmethylbis(trimethylsilyl)arsane 1e and bis[bis(trimethylsilyl)arsano]methane 1f are formed. With tert. butyl chloride a β-elimination results in the formation of bis(trimethylsilyl)arsane; in the reaction with chlorodiphenylmethane and dibromoethane an alkali metal-halogen-exchange takes place yielding tetrakis(trimethylsilyl)-diarsane 6 . On heating bis[bis(trimethylsilyl)arsano]dimethylsilane 7 , synthesized from 5 and dichlorodimethylsilane, to 240°C for several days it decomposes to 4 and dodecamethyl-hexasila-tetra-arsa-adamantane 8 . Tert. butyl- 1g and phenylbis(trimethylsilyl)arsane 1h which cannot be obtained from 5 are prepared from primary arsanes via the corresponding dilithium derivatives.     

Über die Si3-N-bindung: XXXV. Darstellung von N-β-halogenäthyl-N,N-bis(trimethylsilyl)aminen

N-β-Haloethyl-N,N-bis(trimethylsilyl)amines, which can be used for the introduction of aminoethyl groups into organic or organosilicon compounds, are prepared in good yields from N-trimethylsilylaziridine and trimethylhalosilanes. This reaction is spontaneous with trimethylbromo- and -iodosilane, whereas it is necessary to run the reactions with trimethylchlorosilane in the presence of dipolar aprotic solvents and at higher temperatures.N-β-Bromoethyl-N,N-bis(trimethylsilyl)amine (II) is also obtained by silylation of N-β-bromoethylamine hydrobromide with trimethylsilyldiethylamine or with N-trimethylsilyl-N-methyl acetamide. Furthermore N-β-iodoethyl-N,N- bis(trimethylsilyl)amine is prepared by the reaction of II with MgI₂ or of aziridine and N-trimethylsilylaziridine respectively, with trimethylchlorosilane and MgI₂.From the silylation of N-β-bromoethylamine hydrobromide with trimethylsilyldiethylamine N,N-bis(trimethylsilyl)-N′,N′-diethylethylenediamine is isolated as a side product or, at higher temperatures, as the main product.     

Notiz zur Synthese von Alkyl-, Cycloalkyl- und Aryl-(4-aminophenyl)-sulfonen

Syntheses of Some Alkyl-, Cycloalkyl- and Aryl-(4-aminophenyl)-sulfones Syntheses of (4-aminophenyl)-alkyl, -cycloalkyl and -aryl sulfones 2 were achieved both by alkylation of 4-(acetylamino)-benzenesulfinic acid ( 7 ) to the corresponding acetanilides 9 followed by hydrolysis and by oxidation of the appropriate (4-nitrophenyl)-sulfides 11 to (4-nitrophenyl)-sulfones 1 with subsequent Béchamp reduction.     

Reaktionen von Phosphanen und Arsanen mit Diselenkomplexen

The compound [Cp′Mn(CO)₂]Se₂ (1) reacts with primary arsanes and phosphanes, and migration of the carbonylmetal fragment Cp′Mn(CO)₂ (Cp′ = CH₃C₅H₄) from the selenium to the arsenic or phosphorus center occurs. Products of these reactions are diselena-diarsetanes (4) or diselena-diphosphetanes (5). During the reaction of arsanes with 1, arsinidene complexes (2) are obtained in very good yields. Compounds with a PSeP unit (6) can be isolated as by-products of the reaction of phosphanes with 1.     

Palladium-Catalyzed Syntheses of Polyethynyl-Substituted 2,2′-Bithiophenes

The syntheses of polyethynyl-substituted 2,2′-bithiophenes 2 and related 5,5′-dicarbaldehyde derivatives 1 are described. The treatment of easily available polybrominated 2,2′-bithiophenes 3 and 2,2′-bithiophene-5,5′-dicarbaldehydes 4 with phenyl or (trimethylsilyl)acetylene in the presence of Pd^II and Cu^I in (i-Pr)₂NH yields substituted polyethynyl-2,2′-bithiophene compounds. The Me₃Si protecting groups can be removed by protodesilylation under basic conditions to give the corresponding terminal ethynyl groups. These polyethynyl-bithiophenes could be interesting precursors for the synthesis of macrocycles with interesting properties.     

Elektrochemische Synthesen. XXIII. Elektrochemische und EPR-spektroskopische Untersuchung des Redoxverhaltens von (SN)+ und [S3N3]−

Electrochemical Syntheses. XXIII. Electrochemical and EPR-Spectroscopic Investigation of the Redox Behaviour of (SN)⁺ and [S₃N₃]^? The eventual syntheses of SN^. and (S₃N₃)^. by electrochemical reduction or oxidation, respectively, starting from (SN)⁺[SbF₆]^? and (PPN)⁺[S₃N₃]^? were checked by e.p.r. spectroscopy. Only the reduction of (SN)[SbF₆] yielded detectable paramagnetic species: the long-known (S₃N₂)^+. and a radical, the e.p.r. signal of which is a quintet of triplets. This signal is not obtained by electro-chemical oxidation of CF₃CO? N?(S₃N₂) or FSO₂? N?(S₃N₂).     

Synthesen und chemische Reaktionen von ω,ω-Bis(alkylthio)chinonmethiden des 1,6-Methano[10]annulens

Syntheses and Chemical Reactions of ω,ω-Bis(alkylthio)quinonemethides of 1.6-Methano[10]annulenes The syntheses of the donor-acceptor-substituted compounds 3 – 5 , 9 starting from 2 , 7 , or 8 , furthermore, the syntheses of 12 , 15 – 21 are described. The detailed results of ¹H- and ¹³C-NMR-spectroscopic measurements are reported.     

Synthesen,chemische und elektrische Eigenschaften von Tetrathiafulvalen mit 1,6-Methano[10]annulen-Partialstruktur und von Chalcogendiimid-derivaten

Syntheses, Chemical and Electrical Properties of Tetrathiafulvalene with a 1,6-Methano[10]annulene Moiety and of Chalcogendiimide-Derivatives The synthesis of the tetrathiafulvalene 6 has been described: the reaction of 1 with the benzenedithoil 2 yielded the bis-dithioacetal 3 of 1,6-methano[10]annulene-dicarbaldehyde 1 . The oxidation of 3 in the presence of HBF₄ in Et₂O yielded the salt 4 , elimination of a hydride anion with triphenylmethylium tetrafluoroborate the salt 5 , and elimination of a proton in 5 with Et₃N the tetrathiafulvalene 6 with a 1,6-methano[10]annulene moiety. The spectroscopic and electrochemical properties of 6 are described, and also the syntheses and properties of charge-trasnfer complexes 7 and 8 , including the properties of electric conductivity of 7 and 8 . the syntheses of 9-13 are reported and also their spectroscopic properties.     

Bildung und Eigenschaften von Acylphosphinen. II. Verbindungen aus der Reaktion von Tris(trimethylsilyl)phosphin mit Pivaloylchlorid

Syntheses and Properties of Acylphosphines. II. Compounds from the Reaction of Tris(trimethylsilyl)phosphine with Pivaloyl Chloride Tris(trimethylsilyl)phosphine reacts with pivaloyl chloride at +20°C in cyclopentane to form the enol form of pivaloylbis(trimethylsilyl)phosphine. In this compound one trimethylsilyl group is bound to phosphorus, the other to oxygen. As the n.m.r. spectra of the reaction at ?10°C in monoglyme show the thermally instable keto form with two trimethylsilyl groups bound to phosphorus is formed first and rearranges at slightly elevated temperatures. Substitution of the second trimethylsilyl group yields the enol form of dipivaloyltrimethylsilylphosphine. Tripivaloylphosphine with three acyl groups bound to phosphorus and the enol form of tert. butylpivaloyltrimethyl-silylphosphine are produced in side reactions.     

Alkoxylierung von bis(trimethylsilyl)-aminofluorsilanen,sowie siloxanbildung unter äthereliminierung

The reaction of bis(trimethylsilyl)aminofluorsilanes, (Me₃Si)₂NSiF₂R (R = CH₃ or F), with sodium alcoholates or sodium phenylate yields under elimination of NaF alkoxy- and aryloxy-aminofluorosilanes of the composition (Me₃Si)₂NSiF(R)OR′(R′ = CH₃, C₂H₅, C₃H₇, C₆H₅). A disiloxane is formed by thermal elimination of diethyl ether from bis(trimethylsilyl)aminomethylfluoroethoxysilane. The IR, mass, ¹H and ¹⁹F NMR spectra of the above-mentioned compounds are reported. ab]Die Reaktion von Bis(trimethylsilyl)-aminofluorsilanen des Typs (Me₃Si)₂NSiF₂R (R = F, CH₃) mit Natriumalkoholaten und Natriumphenolat führt unter NaF-Abspaltung zu Alkyl- und Aryloxyaminofluorsilanen der Zusammensetzung: (Me₃Si)₂NSiF(R)OR′ (R′ = CH₃, C₂H₇, C₆H₅, C₆H₅). Ein Disiloxan könnte durch die thermische Eliminierung von Diäthyläther aus Bis(trimethylsilyl)aminomethyl-fluor-äthoxy-silylarnin erhalten werden.Die IR-, Massen-, ¹H- und ¹⁹F-NMR-Spektren der dargestellten Verbindungen werden mitgeteilt.     

Diorganostyrylzinndiorganophosphine und ihre tricarbonylnickel-komplexe

Diorganostyryltin chlorides R₂StySnCl (R = C₄H₉, p-CH₃C₆H₄, R₂ = (CH₂)₅) react with trimethylsilyl di-t-butylphosphine or trimethylsilyl diphenylphosphine to form trimethylchlorosilane and the corresponding diorganostyryltin-diorganophosphines, which can be separated and characterized by IR, NMR, Mössbauer and mass spectroscopy. With Ni(CO)₄ the tin—phosphorus derivatives give diorganostyryltin diorganophosphinetricarbonylnickel complexes.     

Ring-Opening Reaction of a Dihydrozirconafuran (= 2,5-Dihydro-1,2-oxazirconole): An equilibrium studied by NMR methods,and its chemical consequences

The dihydrozirconafuran 3 (2,2-di(cyclopenta-2,4-dien-l-yl)-2,5-dihydro-5,5-dimethyl-3,4-bis(trimethylsilyl)-1,2-oxazirconole) is a valuable synthetic equivalent to the 14-electron fragment Cp₂Zr

1 Throughout this paper, C_p=η⁵?C₅H₅

. The reactions of this metallacycle suppose an equilibrium with an ‘opened’ form [ZrCp₂(RC?CR)(acetone)], the latter paving the way to numerous ligand replacements. In a solution containing the dihydrozirconafuran and acetone, these reactions are reversible and degenerate, and can be studied by NMR methods: by two-dimensional spectroscopy and by observation of the isotope-induced chemical shifts that occur upon incorporation of (D₆)acetone into the metallacycle. The findings give an indirect proof of the described equilibrium.     

Synthesen und Eigenschaften von Bis(perfluoralkyl)zink‐Verbindungen

Syntheses and Properties of Bis(perfluoroalkyl)zinc Compounds The conditions for the syntheses of bis(perfluoroalkyl)zinc compounds Zn(R_f)₂ · 2 D (R_f = C₂F₅, n‐C₃F₇, i‐C₃F₇, n‐C₄F₉, n‐C₆F₁₃, n‐C₇F₁₅, and n‐C₈F₁₇; D = CH₃CN, tetrahydrofurane, dimethylsulfoxide) are described. Mass spectra, thermal decompositions, ¹⁹F‐ and ¹³C‐NMR spectra are discussed.     

Synthese und Strukturuntersuchungen von Iodocupraten(I). IX. Synthese und Kristallstrukturen von Cs3Cu2I5 und RbCu2I3

Syntheses and Structure Analyses of Iodocuprates (I). IX. Syntheses and Crystal Structures of Cs₃Cu₂I₅ and RbCu₂I₃ Cs₃Cu₂I₅ and Rb[Cu₂I₃] were prepared by the reaction of CsI or RbI with CuI in solution (acetonitrile or acetone) or by solid state reaction. The crystal structure analysis of Cs₃Cu₂I₅ (orthorhombic, Pbnm, a = 1438.6(6), b = 1014.7(5), c = 1167.5(5) pm, Z = 4) shows, that the compound contains dinuclear anions Cu₂I₅^3? in which the I atoms are arranged to trigonal bipyramids; one Cu^I occupies one of the two I tetrahedral holes, the other a trigonal site of the neighbouring tetrahedron. Rb[Cu₂I₃] (orthorhombic, Cmcm, a = 1070.6(7), b = 1338.3(8), c = 572.8(3) pm, Z = 4) is built up by CuI₄ double chains; the compound is isomorphic with Cs[Cu₂I₃].     

Metallorganische Verbindungen der Lanthaniden. II. Dicyclopentadienyl(di-tert-butylphosphino)terbium, -holmium und -erbium

Organometallic Compounds of Lanthanides. II. Dicyclopentadienyl(di-tert-butylphosphino)terbium, -holmium, and -erbium Lithium(di-tert-butyl)phosphide reacts with dicyclopentadienylterbium or dicyclopentadienylholmium chloride under elimination of lithium chloride and formation of dicyclopentadienyl(di-tert-butylphosphino)terbium or -holmium, respectively. Dicyclopentadienyl(di-tert-butyl-phosphino)erbium is formed by the reaction of dicyclopentadienylerbium chloride with di-tert-butyl-(trimethylsilyl)-phosphine together with trimethylchlorosilane. The i.r. and ¹H-n.m.r. spectroscopic data of the new compounds are given.