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1.
《Journal of organometallic chemistry》1987,322(2):151-161
Reactions of α-stannylvinyllithiums RR′CC(Li)SnMe3 with halides Me3MCl (M = Si, Ge, Pb) give the corresponding mixed bis(trimethylmetal)alkenes RR′CC(SnMe3)3. With two equivalents of methyllithium and trimethyllead chloride, RR′CC(SnMe3)2 can be converted to RR′CC(PbMe3)2. The latter, as well as RR′CC(SnMe3)PbMe3, undergoes transmetallation with methyllithium to give α-plumbylvinyllithiums RR′CC(Li)PbMe3 which are more stable and apparently less basic than the corresponding α-stannyl anions.Multinuclear NMR data for the anionic species are presented and discussed. 相似文献
2.
A series of new polyfluorinated dienes 3, containing the novel -CFCHCHCF-, pattern has been synthesized (50–70% yields) by reacting perfluoroalkyl iodides with perfluoroalkyl-ethylenes in the presence of copper. The monoalkenes RfCFCHCH2CF2R′f and the saturated compounds RfCF2CH2CH2CF2R′f were obtained by varying the experimental conditions. The 1H and 19F NMR spectra are analysed and the reaction mechanism is discussed. 相似文献
3.
M. Tigchelaar J. Meijer H. Kleijn H.J.T. Bos P. Vermeer 《Journal of organometallic chemistry》1981,221(1):117-121
The enynyl oxiranes (I) react with alkylsilver compounds to form butatrienyl carbinols RCH2C(Me)CCC(R′)CR″2OH (IV,V). Alkylcopper reagents, on the other hand, preferentially convert I into allenyl carbinols H2CC(Me)C(R)CC(R′)CR″2OH (III) 相似文献
4.
《Journal of organometallic chemistry》1986,312(3):277-282
Addition at low temperatures of carbon disulfide to a solution of the lithium compound (R1 = CH3, C3H7, Ph, OCH3, SCH3) results in the initial formation of an allenic carbodithioate H2CCC(R1)CSSLi, while for R1 = t-C4H9 or SiMe3 acetylenic carbodithioates R1CCCH2CSSLi are formed. The initial products undergo very rapid subsequent reactions. For R1 = CH3 or C3H7 the lithium compound adds (in the allenic form) in a conjugated fashion to the CCCS system of the allenic carbodithioate. The acetylenic dithioates are deprotonated to give the geminal dithiolates R1CCCHC(SLi)2. For R1 = Ph, OCH3 or SCH3, subsequent deprotonation at the terminal carbon atom of the initial allenic dithioate gives enyne dithiolates HCCC(R1)C(SCH3)2; this reaction proceeds more satisfactorily with the potassium compounds. 相似文献
5.
《Journal of organometallic chemistry》1986,302(2):235-242
Cp(OC)2Mn(THF) reacts with p-diethynylbenzene (Deb), yielding Cp(OC)2Mn(Deb) (I) and [Cp(OC)2Mn]2(Deb) (II) with the η2-acetylene coordination of Deb (to both Mn atoms in II). Under the action of PhLi, I and II are isomerized into Cp(OC)2MnCCHC6H4CCH (III) and [Cp(OC)2MnCCH]2C6H4 (VI). Treatment of I with PhLi, LiBr and an excess of HCl in ether, as well as direct interaction of III with LiBr and HCl/Et2O, gives Cp(OC)2MnCCHC6H4CBrCH2 (IV), which has been characterized by an X-ray single-crystal diffraction study. III adds PPh3, yielding a zwitterionic complex, Cp(OC)2Mn−C(P+Ph3)CHC6H4CCH (V). 相似文献
6.
C. Broquet 《Tetrahedron》1973,29(22):3595-3598
The enolate ylide Ph3P+C?C(Ph)O?Li+ obtained by the reaction of HMPT-Li with the benzoylmethylenetriphenylphosphorane Ph3PCHCOPh reacts with aliphatic ketones, in contrast to its precursor. This condensation makes it possible to prepare β,γ-unsaturated ketones, of type RCHC(R′)CH2COPh, instead of the α,β isomer usually obtained in a Wittig reaction. 相似文献
7.
The reactivity of perfluoroalkenylmagnesium bromides RFCFCFMgBr (RFC4F9, C6F13), obtained from the corresponding l-bromo-perfluoroalkenes, has been investigated.These Grignard reagents react with carbonyl compounds to give, with good yields, a series of new α-β unsaturated polyfluorinated alcohols RFCFCFC(OH)RR′ (1). The synthesis and spectrographic characteristics of these compounds are reported and discussed.Perfluoroalkenyl mercuric and tin derivatives are obtained from the reaction of the perfluorinated Grignard reagents with mercuric salts and organotin halides respectively : Spectroscopic identification and some chemical properties of these new perfluorinated organometallic compounds are given.The good reactivity of these unsaturated derivatives towards protic acids and electrophiles, leading to the cleavage of the perfluoroalkenyl group, is used to study the possibilities of transmetallation reactions.Somes examples of these reactions are reported. 相似文献
8.
Barriers of rotation and inversion, respectively, have been calculated for the species H2CNH (I), H2CNCH3 (II), NHNH (III), NHNCH3 (IV) and their protonated species. For any unprotonated molecule the barrier of inversion is consistently lower than the barrier of rotation. Tile inversion barriers are: 27.8 (I), 23.8 (II), 51.9 (III) and 46.1 (IV) kcal/mole. In the case of azomethine species, protonation results in an increased rotational barrier (from 50.8 to 74.7 kcal/mole for II). In the case of azo species barriers of inversion are lowered on protonation (from 51.9 to 30.1 for II and from 46.1 to 24.4 kcal/mole for IV). All barriers are given with reference to the trans-isomer (azo). Proton affinities for the azomethine species are higher than those of the corresponding azo species (223.3 for 1, 199.9 kcal/mole for II). 相似文献
9.
-N-Isopropylacetimidoyl chloride, CF3CClNCF(CF3)2, has been used as a precursor for a variety of heterocyclic and acyclic compounds. Reaction with azide ion yields a mixture of the imidoyl azide, CF3(N3)CNCF(CF3)2, and the 1,5-tetrazole, CF3CF(CF3)2. Hexafluoropropylideniminolithium produces as a minor product the conjugated diimine, (CF3)2CNC(CF3)NCF(CF3)2, from nucleophilic attack at the imidoyl chlorine and as a major product the triimine, (CF3)2CNC(CF3)NC(CF3)2NC(CF3)2, from further attack at the isopropyl fluorine. A thio-amide, CF3C(S)NHCH(CF3)2, and a Δ3-1,2,4-dithiazoline, (CF3)2, are produced upon reaction of hyrogen sulfide with the imidoyl chloride. Pathways are proposed for each of the reactions. 相似文献
10.
An improved procedure for the preparation of phenyl(fluorodichloromethyl)mercury involving the reaction of phenylmercuric chloride with sodium methoxide and fluorodichloromethane in THF/methanol at ?40° is described. This procedure gives PhHgCCl2F in high yield and generally of about 85% purity. Reactions of the PhHgCCl2F thus prepared with olefins [cyclohexene, cyclooctene, allyltrimethylsilane, vinyltriethylsilane, Me2CCHCl, Me2CC(Br)Me, CH2C(Me)CH2Cl and norbornene] gave the expected cyclopropanes in high yield. This mercury reagent added CClF to the CN bond of PhNCCl2, giving 1-phenyl-2-fluoro-2,3,3-trichloroaziridine and to the CS bond of thiobenzophenone. The thiirane formed was, however, unstable to the reaction and work-up conditions and only its desulfurization product, Ph2CCClF, could be isolated. Fluorochlorocarbene transfer from this mercurial also could be induced by the action of sodium iodide in DME. Evidence is presented which shows that PhHgCCl2F is more reactive in CClF transfer than indicated in a previous report. 相似文献
11.
Henk Kleijn Hans Westmije John Meijer Peter Vermeer 《Journal of organometallic chemistry》1980,192(2):275-281
Functionally conjugated enynes, H2CC(R1)CCCR2R3OS(O)Me, undergo 1,5-substitution with alkylsilver(I) reagents, RAGG ☆ 3 LiBr. The purity of the produced alkylated butatrienes, RCH2C(R1)CCCR2R3 depends on the nature of R in RAg ☆ 3 LiBr and on the substituents R1, R2 and R3 in the substrate. 相似文献
12.
《Journal of organometallic chemistry》1987,322(2):141-150
The influence of intramolecular coordination and solvent effects on the formation and stability of α-stannylvinyllithium reagents RR′CC(Li)SnMe3 (R′ = H, alkyl, aryl) has been investigated; intramolecular coordination via a 5-membered ring is particularly effective. Mechanisms for the isomerisation and thermal decomposition of RR′CC(Li)SnMe3 are discussed, and multinuclear NMR data (119Sn, 13C and 1H) for these species are presented. 相似文献
13.
《Journal of organometallic chemistry》1986,314(3):333-355
Bis-alkenyl complexes of the type (η-C5H5)2RH2(alkene − H)(alkyne + H) are obtained when the alkyne complex (η-C5H5)2Rh2(CO)(CF3C2CF3) is treated with the following alkenes: H2CCH2, H2CCHR (R = Me, But, Ph, CN), H2CCF2, RHCCHR′ (R = R′ = Me, Ph, Cl; R = Me, R′ = Et), cyclooctene and norbornene. An approximately equimolar amount of (η-C5H5)2Rh2(CO)2(CF3C2CF3) is also formed. The reactions are greatly accelerated when the reaction mixtures are exposed to sunlight. There is some regioselectivity in the reactions with H2CCHR and MeHCCHet, with a preference for CH bond cleavage at the least crowded alkene-carbon. When the reaction with acrylonitrile is performed in the absence of sunlight, the complex (η-C5H5)2(CO){(H2CCHCN)(CF3C2CF3)} can be isolated; upon exposure to sunlight, there is loss of CO and H-transfer to form two isomers of the appropriate bis-alkenyl complex.The molecular geometries of (η-C5H5)2Rh2(CHCHCN){C(CF3)C(CF3)H} and (η-C5H5)2Rh2(CHCF2){C(CF3)C(CF3)H} have been ascertained by X-ray structure determination. Each molecule has two bridging alkenyl units spanning a RhRh single bond; the dihedral angle between the two RhRhCC planes is just above 90°. There is a cyclopentadienyl ring η5-attached to each metal. Crystal data: C17H13F6NRh2·H2O, M 569.1, monoclinic, P21/n, a 15.014(7), b 14.882(7), c 8.590(5) Å, β 94.57(9)°, Z = 4, final R 0.056 for 2493 observed reflections; C16H12F8Rh2, M 562.1, monoclinic, P21/c, a 13.037(6), b 8.765(2), c 14.873(3) Å, β 103.16(3)°, Z = 4, final R 0.062 for 1820 observed reflections. 相似文献
14.
Carl W.F.T. Pistorius 《Journal of solid state chemistry》1975,13(4):325-329
The phase diagram of Li2WO4, previously studied by Yamaoka et al. (J. Solid State Chem.6, 280 (1973)) has been revised. Li2WO4 II is stable at atmospheric pressure below ~310°C. This phase appears to be a modified spinel, and is tetragonal, a, c = 11.941, 8.409Å, Z = 16, space group . The melting curve of phenacite-type Li2WO4 I rises with pressure with a slope of 0.9°C/kbar to the III/I/liquid triple point at 3.1 kbar, 743°C, beyond which the melting curve of orthorhombic Li2WO4 III rises steeply with pressure (initial slope 31°C/kbar). The Li2WO4 transition line at 3 kbar is almost independent of temperature, i.e., the transition entropy is zero. Li2WO4 II is 21.3% denser than Li2WO4 I at ambient conditions. 相似文献
15.
A reaction of (trimethylsilylmethylene)dimethylphenylphosphorane, PhMe2PCHSiMe3 (I), with phenyl isocyanate affords a 2/1 insertion product, which results from insertion of phenyl isocyanate into both the CSi and CH bonds of I. By way of contrast, a reaction of isothiocyanate and carbon disulfide with I affords 1/1 products by insertion of these heterocumulenes into the CSi bond of I. In these reactions, Wittig-type elimination of dimethylphenylphosphine oxide or sulfide did not occur because of irreversible migrations of the trimethylsilyl group to the anionic centers of the Zwitterionic intermediates. 相似文献
16.
Joseph S. Thrasher Gennaro A. Iannaccone Narayan S. Hosmane Donald E. Maurer Alan F. Clifford 《Journal of fluorine chemistry》1981,18(4):537-551
Reactions of SF5NSF2 with sodium alkoxides and aryloxides have produced both the mono- and disubstituted derivatives SF5NS(F)OR and SF5NS(OR)2, where RCH3, CH2CHCH2, C6H5, p-C6H4NO2, p-C6H4Br, p-C6H4CN. The reaction of SF5NSCl2 with AgNCO produced SF5NS(NCO)2. This diisocyanate can also be prepared from the reaction of SF5NSCl2 with KOCN in liquid SO2. The proposed intermediate, SF5NSO, in the hydrolysis of SF5NSF2 was prepared from the low temperature reaction of SF5NSCl2 and Ag2O in C6H5NO2. The new pentafluorosulfanyl derivatives were characterized by IR, 1H and 19F NMR, mass spectrometry and where possible 13C NMR and elemental analysis. 相似文献
17.
Ternary Hydroxides. I. Synthesis, Structure, and Properties of Li2[Sn(OH)6] · 2 H2O Colourless crystals of Li2[Sn(OH)6] · 2 H2O were synthesized by reaction of SnCl4 with LiOH in aqueous solution. The crystal structure was determined from single crystal data. Li2[Sn(OH)6] · 2 H2O: monoclinic, P21/n (Nr. 14), a = 502.3(1), b = 692.3(1), c = 1020.2(3) pm, β = 99.78(1)°, V = 349.6(2) · 106 pm3, Z = 2, R/Rw = 0.0192/0.0472, N(I) > 2σ(I) = 1527, N(Par.) = 54. Within the crystal structure only slightly distorted octahedrally [Sn(OH)6]2? ions are bonded via hydrogen bonds with water molecules forming layers, which themselve are linked by tetrahedrally coordinated Li ions; the structure is in accordance with the IR-data and the results of the 119Sn solid state NMR-spectroscopy; the hydrat water is eliminated at 117.1°C, the condensation reaction – forming the ternary oxide – takes place at 257.7°C. 相似文献
18.
The vinyl Isocyanides 2,4,6-(CH3)3C6H2CHCHNC and (CH3)3CCHCHNC and the new 1,3-dienyl isocyanide CH3CHCH(CH3)-CHCHNC have been prepared from the corresponding aldehydes and methyl isocyanide using a method first developed by Schöllkopf, Stafforst, and Jentsch. 5 The new vinyl isocyanides (CH3)2CCHNC and CH3CHC(CH3)NC have been prepared by the Cu2O-catalyzed isomerization of the corresponding allyl isocyanides The liquid vinyl isocyanides may be characterized by the formation of solid cis-(RNC)2Mo(CO)4 derivatives through reaction with norbornadienetetracarbonylmolybdenum in hexane solution at ambient temperature. Examination of these molybdenum carbonyl complexes by proton and carbon-13 NMR spectroscopy Indicates that the isocyanide carbon atom but not the carbon-carbon double bond of the vinyl 1socyanide ligands is bonded to the molybdenum atom. The proton-decoupled carbon-13 NMR spectra of the vinyl isocyanides, but not their molybdenum carbonyl complexes, indicate coupling of the isocyanide nitrogen to both the isocyanide carbon (1J(C-N)6 Hz. ) and the vinyl carbon bearing the isocyanide group (1J(C-N)11-13 Hz. ) leading to 1:1:1 triplets for these resonances. These vinyl carbonyl resonances are used to estimate the cis-trans isomer ratios in vinyl isocyanides of the type RCHCHNC. Such studies suggest that the formation of vinyl isocyanides by the copper(I) catalyzed isomerization of the corresponding allylic isocyanides is more nearly stereospecific than the formation of vinyl isocyanides by the elimination reaction of the Schollkopf/Stafforst/Jentsch synthetic method. 相似文献
19.
The reaction of vinyl complexes Cp(CO)(R3P)FeC(OMe)CH2 (R Me, R Ph) with the methylating reagents MeX (X OSO2F, I) in the molar ratio 1/1 affords a mixture of the carbene complexes [Cp(CO)(R3P)FeC(OMe)R]X (R Me, Et, i-Pr). Their formation is explained via a series of acid/base equilibria established between vinyl and carbene complexes. 相似文献
20.
Experimental data on conformational energies of the molecules FH2CHCCH2, FH2CFCCH2, FH2C(CH3)C&.dbnd;CH2 trans-FH2CHCC(CH3)H have been used to establish parameter values for the nonbonding atom ⋯ atom interaction F ⋯ C(sp2) within the Morse potential formulation. Torsional potentials have been calculated for the four molecules mentioned above and in addition for cis- and trans-FH2CHCCHF, (FH2C)2CCH2, cis-FH2CHCCHCH2F, CH3FCHHCCH2 and FH2CCH2HCCH2. Calculated results have been compared with experimental values. Torsional force constants for the molecules have been obtained. A comparison between fluoro, chloro and bromo compounds is presented. 相似文献