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1.
The 29Si, 13C and 1H NMR spectra of mixtures of Me3SiI and Me3SiOSO2CF3 with DMF in CD2Cl2 show signals that are consistent with the formation of Me3SiOH(NMe2)X? but not with penta- or hexa-coordinate silicon species. The spectra of a mixture of Me3SiBr and DMF show a rapidly exchanging, equilibrium mixture of Me3SiOH(NMe2)Br? and starting materials. No strong evidence for salt formation between DMF and Me3SiCl was obtained. The spectra of Me3SiX (X = I, Br, Cl, OSO2CF3) in CD3CN indicate that neither adduct formation nor extra coordination at silicon is significant. 相似文献
2.
A study of the reaction of Me3SnCu·.Me2S (1) and [Me3SnCuSPh]Li (2) with α,β - acetylenic N,N-dimethylamides 3 shows (a) that the overall process can be controlled experimentally so as to produce either N,N-dimethyl ()-(4) or ()-3-trimethylstannyl-2-alkenamides (5), (b) that the initially formed intermediate derived from interaction of 2 and 3 is significantly more stable than that obtained by reaction of 2 and α,β-acetylenic esters, and (c) that the intermediate produced by treating 3 with 1 can be trapped with electrophiles other than proton. 相似文献
3.
Ronald E. Banks Ismail M. Farhat Roy Fields Robin G. Pritchard Mohamad M. Saleh 《Journal of fluorine chemistry》1985,28(3):325-340
The nitrosoarenes ArNO (Ar = C6H5, 2-MeC6H4, 2,4,6- Me3C6H2 and C6F5) have been condensed with 4-(dichloroamino)- tetrafluoropyridine to provide the azoxy-compounds pyFN()Ar (pyF = 2,3,5,6-tetrafluoro-4-pyridyl); de-oxygenation of the first three with triphenylphosphine or triethyl phosphite gave the corresponding azo-compounds, and the reverse reaction was achieved in the case of pyFNNC6H2Me3-2,4,6 using peroxytrifluoroacetic acid. Thermolysis of 4-azidotetrafluoropyridine in the presence of pentafluoronitrosobenzene provided the perfluorinated azoxy-compound pyFN()C6F5. X-Ray methods have been used to determine the molecular geometry of pyFN()C6H2Me3-2,4,6. 相似文献
4.
Federico G. De las Heras Ana San Félix Ana Calvo-Mateo Piedad Fernández-Resa 《Tetrahedron》1985,41(18):3867-3873
Reaction of methyl 2-acetamido-4,6--benzylidene-2-deoxy-α---hexopyranosid-3-ulose with Me3SiCN afforded methyl 2-acetamido-4,6--benzylidene-3--cyano-2-deoxy-3--trimethylsilyl-α--- Reaction of ethyl 4,6-di--acetyl-2,3-anhydro-α--mannopyranoside with Me3SiCN gave the corresponding ethyl 4,6-di--acetyl-2--cyano-2-deoxy-α--glucopyranoside. Reaction of methyl 4,6--benzylidene-2,3-anhydro-α--allopyranoside or methyl 4,6--benzylidene-2,3-di--tosyl-α--glucopyranoside with Me3SiCN at - 75° or - 50° gave the corresponding methyl 6--[(R)-cyano phenyl methyl]-α--glyco-pyranosides with high or total regio and stereoselectivity. 相似文献
5.
Colin Eaborn Peter B. Hitchcock Paul D. Lickiss 《Journal of organometallic chemistry》1981,221(1):13-17
The structure of the crowded molecule (Me3Si)3C(SiMe2Ph) has been determined by single crystal X-ray diffraction. The steric strain manifest itself mainly in lengthening of the Me3SiC and Me2PhSiC bonds (average length 1.920(6) ) and closing up of the CSiC angles within the Me3Si and Me2PhSi groups (average 105.2(10)°), with correspondingly large C(1)SiC angles (113.5(13)°; C(1) is the central carbon atom). 相似文献
6.
Peter K. Byers Allan J. Canty Karen Mills Louise Titcombe 《Journal of organometallic chemistry》1985,295(3):401-405
The complexes Me2Au(R2pz) (R = H, Me; pzH = pyrazole) are formed on reaction of dimethylgold(III) nitrate with 3,5-disubstituted pyrazoles, R2pzH, in water, but a similar procedure with Ph2pzH followed by recrystallization from CHCl3/CCl4 gives [Me2Au(Ph2pzH)2]NO3 · ca.CCl4. The complexes Me2(Ph2pz) (M = Au, Tl), Me2In(Ph2pz)·CH2Cl2, and Me2Tl(Me2pz) are formed on reaction of Me2MI (M = Au, Tl) or Me2InCl with Ag(R2pz) in nonaqueous solvents. The complexes Me2Au(R2pz) (R = H, Me, Ph) are dimeric in chloroform and Me2Tl(Me2pz) is dimeric in benzene, but osmometric data for Me2Tl(Ph2pz) in benzene indicate presence of a monomer—dimer equilibrium. 相似文献
7.
13C NMR spectra of derivatives of cyclohexane, piperidine, and thian in chair and twist eonformers, and of model compounds, lead to estimates of deshielding (Δδ = 3.6 ± 0.2 ppm) for axial C3 on a cyclohexane ring and shielding (Δδ = ?0.2 to ?0.6 ppm) for ψe-C3 in twist conformers, relative to equatorial C3. Ring carbon atoms are considerably shielded in twist conformers relative to chair eonformers. The value of 13C chemical shifts in the study of chair-twist equilibria is exemplified by variable temperature measurements on diastereomeric pairs of compounds (11 and 13; 38 and 50). 相似文献
8.
Georg Grötsch Wolfgang Malisch Herbert Blau 《Journal of organometallic chemistry》1983,252(2):C19-C22
The reaction of the phosphonium metallates Me4P[C5R5(CO)(Me3P))R′] (M = W, R = H, R′ = Et (1a); M = Mo, R = Me, R′ = Me (1b)) with the silylating reagent Me3SiOSO2CF3 yields the neutral complexes C5R5(CO)(Me3P))R (2a, 2b) bearing a chelating O(2), C(4)-trimethylsiloxybutenone ligand. The structure of the new compounds is established by the IR, 1H and 31P NMR spectra. 相似文献
9.
Alkenes a–d interact at ?80°C in 15 min. with the Vilsmeier reagent (Me2N=CHCl)+PO2Cl2? in presence of 30% H2O2 to yield the corresponding epoxides a–d. The reaction could involve the formation of the highly reactive hydroperoxymethylenedimethylammonium salt (Me2N=CHOOH)+PO2Cl?2. 相似文献
10.
The Ni- or Pd-catalyzed reaction of alkenyl iodides with Me3SiCH2Mgcl provides various types of allytrimethylsilanes in excellent yields in a highly stereo- and regioselective manner, while the Zr-catalyzed carboalumination of Me3SiCH2CCH followed by replacement of Al with carbon groups by known reactions produces allylsilanes represented by . 相似文献
11.
The chelating ligand Me3COSiMe2N(CMe3)H (III) can easily be prepared in high yields and has been employed for the synthesis of some metal derivatives. With n-butyllithium III forms [Me2Si(Me3CO)(Me3CNLi)]2 (IV), which is found to be dimeric in solution and in the gas phase. When IV is allowed to react with thallium(I) chloride in diethyl ether the monomeric, highly reactive Me2Si- (Me3C) (II) is formed under precipitation of lithium chloride. The cyclic structure and the physical properties of II can be understood on the basis of isosteric relation to cyclic diazasilastannylenes. II forms the tetramer (TlOMe)4 with methanol and does not add methyl iodide to the metal, the thalium containing product being TII. With magnesium dichloride in diethyl ether yields thallium(I) chloride and the spiro compound [Me2Si(Me3CO)(Me3CN)]2-Mg (VI), in which magnesium exhibits 4-fold coordination. 相似文献
12.
Reaction of Me5C5Li and Ni(CO)4 gave [(n5-Me5C5)Ni(CO)]2 () in 40 % yield. Reaction of with iodine followed by addition of a tertiary phosphine or reaction of (PPh3)2NiX2 with Me5C5Li or Me5C5SnBu3 gave (n5-Me5C5)Ni(L)X () (L = tertiary phosphine, X = halogen). Treatment of with RLi (R = Me, PhCC) afforded (n5-Me5C5)Ni(L)R (). The spectroscopic properties and the reactivities of n5-pentamethylcyclopentadienylnickel complexes indicate that the n5-Me5C5 ligand is more electron-donating and a sterically more bulky than the n5-C5H5 ligand. 相似文献
13.
Martin A. Bennett Tai-Nang Huang Jozef L. Latten 《Journal of organometallic chemistry》1984,272(2):189-205
The η-hexamethylbenzenehydridoruthenium(II) complexes RuHCl(η-C6Me6)L (L = PPh3 (11), AsPh3 (12), P(C6H4-p-F)3 (14), P(C6H4-p-Me)3 (15), P(C6H4-p-OMe)3 (16), P-t-BuPh2 (17), P-i-PrPh2 (18), P-i-Pr3 (19), PCy3 (20) and P-t-BuMe2 (21)) have been made by heating [RuCl2(η-C6Me6)]2, the ligand and sodium carbonate in propan-2-ol. The triarylphosphine complexes 11, 14 and 15 react with methyllithium to give aryl ortho-metallated hydridoruthenium(II) complexes such as Ph2)(η-C6Me6) (22) and 19 similarly gives the isopropyl cyclometallated complex -i-Pr2(η-C6Me6) (29) as a mixture of diastereomers. Reaction of 17 with methyllithium gives initially the t-butyl cyclometallated complex Ph2)(η-C6Me6) (25) which isomerizes by a first order process (k.2 h?1 in C6D6 or THF-d8 at 50°C) to the aryl ortho-metallated complex -t-BuPh)(η-C6Me6) (26). The similarly generated isopropyl cyclometallated complex Ph2)(η-C6Me6) (27) has not been isolated in a pure state owing to rapid isomerization to -i-PrPh)(η-C6Me6) (28); both 27 and 28 exist as a pair of diastereomers. The formation of the cyclometallated complexes and the isomerizations are thought to involve intermediate 16-electron ruthenium(O) complexes Ru(η-C6Me6)L. 相似文献
14.
The isotropic ESR spectra of a number of phosphonyl radicals (X2O), the dimethylphosphinyl radical, and the phosphoranyl radical (MeO)3OBu-t, are described, and accurate values of the phosphorus hyperfine splittings and g-factors are reported. For X2O, the value of a(P) increases and the g-factor decreases as the electronegativity of X increases. There is a linear relationship between a(P) for X2O and 1J(PH) for X2P(O)H, but the same relationship does not hold for Me2P- and Me2PH. The spectrum of the di-n-hexylphosphonyl radical shows coupling to two pairs of α-methylene protons, and this non-equivalence is attributed to the pyramidal structure of the phosphonyl radical. 相似文献
15.
par Annick Panaye Jean-Pierre Doucet Jacques-Emile Dubois 《Tetrahedron letters》1981,22(13):1235-1238
In di-tertiary groups like (Me3C)213C, the sixth methyl substituent or the induced 13C chemical shift of sp2 or sp3 sites (Bσ and yπ effects). 相似文献
16.
Compounds MIIMeIVF6 requently undergo phase transitions from the cubic ordered ReO3 to the trigonal LiSbF6 structure when lowering the temperature. In case of a strongly Jahn-Teller unstable cation in the MII position additional phases may occur. Results of powder neutron-diffraction studies on CaSnF6, FeZrF6, and CrZrF6 at different temperatures are reported. The high-temperature phases have the space group Fm3m; the F? ligands are either statistically displaced from the MIIMeIV directions or undergo a strong thermal motion perpendicular to these directions (: 165–180°). The thermal ellipsoids of the CrF bonds are strongly indicative of a dynamical Jahn-Teller effect in addition. In the low-temperature phases of CaSnF6 and FeZrF6 (space group ) the is more distinctly bent (?155–160°). CrZrF6 undergoes two reversible phase transitions, which are determined to occur at 415 ± 5 K (cubic → tetragonal, dynamic to static Jahn-Teller distortion of CrF6 octahedra and 150 ± 10 K (tetragonal → (pseudo)monoclinic). 相似文献
17.
Reaction of the amines (CF3)2NX (X=Cl,Br) with norbornadiene either in solvent (CH2Cl2) at ?78 °C in the dark or in the vapour phase at 20 °C in daylight gives a mixture of 3-halogeno-5-(-bistrifluoromethylamino)nortricyclene (, -and , -isomers) and -5-(-bistrifluoromethylamino)- -7-halogenonorbornene in quantitative yield formed halonium ion addition to the diene. The reaction of the amine (CF3)2NBr in solvent Me2O or Et2O at ?78 °C in the dark gives the same products in low yield, together with 3-bromo-5-alkoxynortricyclene (, - and , -isomers) and the amine (CF3)2NR (R=Me, Et) in high yield. 相似文献
18.
Augusto De Renzi Achille Panunzi Michaelangelo Scalone Aldo Vitagliano 《Journal of organometallic chemistry》1980,192(1):129-132
Amination of PtII-allene complexes of the type cis[PtCl2(Me2CCCHR)(PPh3)] gives the new four-membered C, N chelate aminoalkenyl complexes [Me2(PPh3)Cl]. These undergo ready insertion of carbon monoxide into the CPt σ-bond; the resulting acyl complexes are oxidized by hydrogen peroxide to aminoacidato complexes, and the free unsaturated β-aminoacids can be recovered in good yield by ligand displacement. 相似文献
19.
Colin Eaborn Duncan A.R Happer Kazem D Safa 《Journal of organometallic chemistry》1980,191(2):355-362
The compounds TsiSiR2X [Tsi = Me3Si)3C; R = Me, X = Cl, Br, I, or R = Ph, X = F, Cl, Br, I)] react with boiling 2 M MeONa-MeOH to give products of the type (Me3Si)2CHSiR2OMe. It is suggested that the reaction proceeds through an elimination, analogous to E2 eliminations of alkyl halides, involving synchronous attack of MeO? at an Me3Si group, liberation of X?, and formation of (Me3Si)2CSiR2. The compounds TsiSiPhMeF TsiSiPhCl2 react analogously to give (Me3Si)2CHSiPhMe(OMe) and (Me3Si)2CHSiPh(OMe)2 [tha latter presumably by solvolysis of the initially-formed (Me3Si)2CHSiPhCl(OMe)]. The compounds TsiSiMe2OMe and TsiSiMe3 do not react, while TsiSiMe2H gives TsiH. The compound TsiSiCl3 reacts with 0.1 M MeONa-MeOH to give the substitution and elmination products TsiSiCl2(OMe) and (Me3Si)2CHSi(OMe)3 in ca. ratio. 相似文献
20.
Treatment of (E)-2-methyl-1=-alkenylalanes (), readily obtainable via Zr-cata-lyzed reaction of Me3Al with 1=alkynes, with β-methoxydialkylboranes producers the corresponding alkenylboranes, while sequential treatment of with n-Buli and X2ZrCp2 (X = Cl or I) provides the desired monoalkenylzirconium derivatives, the product yields for both reactions beig 85-100%. 相似文献