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1.
Katsumi Kakinuma 《Tetrahedron》1984,40(11):2089-2094
Chemical synthesis ofD-(6R)- and D(6S)-(6-2H1) glucose is described comprising (i) formation of 6-2H1)-3-o-benzyl-5,6-dideoxy-l, 2-0-isopropylidene-α-D-xylo-hex-5-ynofuranose from D-glucose; (ii) stereospecific reduction of the deuterated acetylene functionality to (E)- or (Z)-deuterated olefin; (iii) stereospecific cis-dihydroxylation of the deuterated olefin; and (iv) separation of stereoisomers based on the intrinsic chirality of D-glucose and subsequent deprotection. 相似文献
2.
Complexes of 5-(phenylazo)-2-thiohydantoin (L1) and 5-(2-hydroxyphenylazo)-2-thiohydantoin (HL2) with Co(II), Ni(II) and Cu(II) salts have been synthesised and characterized by elemental analysis, conductivity, magnetic susceptibility, UV-Vis, IR, ESR and TG studies. The magnetic and spectral data suggested octahedral geometry for [L1M(OAc)2(H2O)2]·xH2O {M=Nill and Cull} and [L1CuCl2(H2O)]·H2O (dimeric form for the latter), trigonal bipyramidal geometry for [L2Co(OAc)(H2O)]·2H2O, square pyramidal geometry for [L2Ni(OAc)(H2O)]·H2O and square planar geometry for [L2CuCl]·2H2O. TG studies confirmed the chemical formulations of these complexes and showed that their thermal degradation takes place in three to five steps, depending on the type of the ligand and the geometry of the complex. The kinetic parameters (n, E#, A, ΔH#, ΔS# and ΔG#) of the thermal decomposition stages were computed using the Coats-Redfern and other standard equations and are discussed. 相似文献
3.
Double asymmetric induction in Michael reactions has been studied. Enantioselective alkylation of a cyclic ketone (1-indanone) with α-phenyl-nor-gramine was carried out. The relative configuration of (2S∗)-2-[(R∗)-1H-indol-3-yl(phenyl)methyl]-2,3-dihydro-1H-inden-1-one was established by X-ray diffraction. The relative configuration of (R∗,R∗,S∗)- and (S∗,R∗,S∗)-2-1H-indol-3-yl(phenyl)methyl]-2,3-dihydro-1H-inden-1-ols was established by 1H NMR studies. 相似文献
4.
Reactions of 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid (H3PyIDC) with a series of Ln(III) ions affords ten coordination polymers, namely, {[Ln(H2PyIDC)(HPyIDC)(H2O)2]·H2O}n [Ln=Nd (1), Sm (2), Eu (3) and Gd (4)], {[Ln(HPyIDC)(H2O)3]·(H2PyIDC)·H2O}n [Ln=Gd (5), Tb (6), Dy (7), Ho (8) and Er (9)], and {[Y2(HPyIDC)2(H2O)5]·(bpy)·(NO3)2·3H2O}n (10) (bpy=4,4′-bipyridine). They exhibit three types of networks: complexes 1-4 are isomorphous coordination networks containing neutral 2D metal-organic layers, while complexes 5-9 are isomorphous, which consist of cationic metal-organic layers and anionic organic layers, and complex 10 is a 2D network built up from 4-connected HPyIDC2− anion and 4-connected Y(III) ions. In addition, thermogravimetric analyses and solid-state luminescent properties of the selected complexes are investigated. They exhibit intense, characteristic emissions in the visible region at room temperature. 相似文献
5.
We report two methods for preparing N-arylammonio, N-pyridyl and N-arylamino dodecaborates: heating of the tetrabutylammonium salt of dodecahydro-closo-dodecaborate(2-) with aryl and pyridyl amines, or nucleophilic attack of [closo-B12H11NH2]2− on a strongly deactivated aromatic system. With aryl amines we obtained [1-closo-B12H11N(R1)2C6H5]− (R1 = H, CH3). With 4-(dimethylamino)pyridine, [1-closo-(B12H11NC5H4)-4-N(CH3)2]−, with a bond between the boron and the pyridinium nitrogen, was obtained. A presumable mechanism for this kind of reactions is reported. By nucleophilic substitution, two products, [1-closo-(B12H11NHC6H3)-3,4-(CN)2]2− and [1-closo-(B12H11NHC6H2)-2-(NO2)-4,5-(CN)2]2−, were formed with 4-nitrophthalonitrile and 1-chloro-2,4-dinitrobenzene gave [1-closo-(B12H11NHC6H3)-2,4-(NO2)2]2−. For [1-closo-B12H11N(CH3)2C6H5]− and [1-closo-(B12H11NHC6H3)-2,4-(NO2)2]2− single crystal X-ray structures were obtained. 相似文献
6.
《Journal of organometallic chemistry》2006,691(24-25):5423-5430
The reaction of (SPY-5-34)-dichloro-(κ2(C,O)-2-formylbenzylidene)(H2IMes)ruthenium (H2IMes=1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene) with potassium hydridotris(pyrazolyl)borate (KTp) in dichloromethane yielded an unusual ruthenium complex chloro(κ3(N,N,N)-chlorotris(pyrazolyl)borate)(κ2(C,C)-1-(2,4,6-trimethylphenyl)-3-(4,6-dimethylphenyl-2-methylidene)-4,5-dihydroimidazol-2-ylidene)ruthenium (2). In 2, a chlorotris(pyrazolyl)borate ligand, which had been created during this reaction, binds in κ3(N,N,N)-mode to the central ruthenium atom. Additionally, a double C–H activation of a methyl group of the H2IMes resulted in the formation of a chelating N-heterocyclic biscarbene ligand and liberation of the former 2-formylbenzylidene as 2-methylbenzaldehyde. Formally, a double hydrogen transfer from a methyl group of the H2IMes to the initial carbene carbon occurred. 2 was characterized by NMR spectroscopy, elemental analysis and single crystal X-ray structure determination. The reaction of KTp with (SPY-5-34)-dichloro(κ2(C,O)-2-ethoxycarbonylbenzylidene)(H2IMes)ruthenium, on the other hand, gave the expected product chloro(κ3(N,N,N)-hydridotris(pyrazolyl)borate)(H2IMes)(2-ethoxycarbonylbenzylidene)ruthenium (6). Compound 6 was characterized by NMR spectroscopy, elemental analysis and single crystal X-ray structure determination. Investigations of the relative activities of these complexes in model ring opening metathesis polymerizations showed a pronounced thermal latency. Polymerizations proceeded at temperatures above 100 °C in case of 6 and 130 °C in case of 2. 相似文献
7.
Daniel Carmona Roberto Medrano Isabel T. Dobrinovich Fernando J. Lahoz Joaquina Ferrer Luis A. Oro 《Journal of organometallic chemistry》2006,691(26):5560-5566
Half-sandwich complexes of formula [(ηn-ring)MClL]PF6 [L = (S)-2-[(Sp)-2-(diphenylphosphino)ferrocenyl]-4-isopropyloxazoline; (ηn-ring)M = (η5-C5Me5)Rh; (η5-C5Me5)Ir; (η6-p-MeC6H4iPr)Ru; (η6-p-MeC6H4iPr)Os] have been prepared and spectroscopically characterised. The molecular structures of the rhodium and iridium compounds have been determined by X-ray crystallography. The related solvate complexes [(η5-C5Me5)ML(Me2CO)]2+ (M = Rh, Ir) are active catalysts for the Diels-Alder reaction between methacrolein and cyclopentadiene. 相似文献
8.
Complexes of Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and U(IV)O2 with (Z)-2-oxo-2-(2-(2-oxoindolin-3-ylidene)hydrazinyl)-N-phenylacetamide (H2OI) are reported and have been characterized by various spectroscopic techniques like (IR, UV–Vis, ESR 1H and 13C NMR) as well as magnetic and thermal (TG and DTA) measurements. It is found that the ligand behaves as a neutral tridentate, neutral tetradentate, monoanionic tridentate, monoanionic tridentate and dianionic tridentate. An octahedral geometry for all complexes except [Cu2(H2OI)(OAc)4](H2O)2 and [Cu(HOI)Cl](H2O)2 which have a square planar geometry. Furthermore, kinetic parameters were determined for each thermal degradation stage of some studied complexes using Coats–Redfern and Horowitz–Metzger methods. The bond lengths, bond angles, HOMO, LUMO and dipole moments have been calculated to confirm the geometry of the ligand and the investigated complexes. 相似文献
9.
Gerard Van Koten Cees A. Schaap Johann T.B.H. Jastrzebski Jan G. Noltes 《Journal of organometallic chemistry》1980,186(3):427-445
The synthesis and structural characterization by 1H NMR and 197Au Mössbauer spectroscopy as well as by chiral labelling of the built-in ligands of three different types of arylgold(I) compounds is described.197Au Mössbauer data revealed that the benzyl- and arylgold(I) triphenylphosphine complexes which bear potential coordinating substituents at an ortho position still contain linearly coordinated AuI with 2c-2e gold(I)carbon bonds. The observation of isochronous NME resonances in (S)-2-Me2NCH(Me)C6H4AuPPh3 confirms that no additional intramolecular AuN coordination occurs in solution. Preliminary results of an X-ray diffraction study of 2,6-(MeO)2C6H3AuPPh3 are reported (R = 0.040, PAuC1 angle 172.6°. Unsymmetrical AuC1C2 and AuC1C6 angles of 126.4 and 117.4°, respectively).Pure, uncomplexed arylgold(I) compounds have been isolated from the reaction of diarylgoldlithium compounds (arylaurates) with trimethyltin bromide. (S)-2-Me2NCHMeC6H4Au has a dimeric structure which most likely consists of two monomeric units associated by intermolecular AuN coordination thus forming a ten-membered chelate ring. The structure of insoluble 2-Me2NCH2C6H4Au and 2-Me2NC6H4Au are less clear. The former compound probably has a structure similar to (S)-2-Me2NCHMeC6H4Au (IS/QS values for two-coordinate AuI centers). However, the strongly deviating IS and QS values of 2-Me2NC6H4Au indicate that a polynuclear structure for this compound similar to that proposed for 2-Me2NC6H4Cu cannot be excluded (a polymeric structure containing 2-Me2NC6H4 groups which span three Au atoms by 3c-2e Au2C bonds and AuN coordination).The mixed Au/Cu cluster (2-Me2NCH2C6H4)4Au2Cu2 is accessible via the reaction of (2-Me2NCH2C6H4)4Au2Li2 with CuI. Molecular weight and 1H NMR studies point to a tetranuclear structure in solution, while mass spectrometry shows fragment ions with m/e corresponding to (2-Me2NCH2C6H4)3Au2Cu2+, (2-Me2NCH2C6H4)3Cu2Au+, (2-Me2NCH2C6H4)2CuAu2+ and of (2-Me2NCH2C6H4)2Au+. 相似文献
10.
Extraction of lutetium(III) and erbium(III) with 1-(2-pyridylazo)-2-naphthol (PAN or HL) in carbon tetrachloride from aqueous solutions was examined. The composition of the complex extracted was determined and it was found that the extraction process can be described by the following equation (Ln 3+=Lu, Er): $$Ln(H_2 O)_m^{3 + } + 3 HL_{(0)} \mathop \rightleftharpoons \limits^{K_{ex} } LnL_{3(0)} + 3 H^ + + mH_2 O$$ The extraction constants (K ex ) and two-phase stability constants (β 3 x ) forLnL 3 complexes have been evaluated. 相似文献
11.
Racemic 8-ethoxy-2-(4-fluorophenyl)-3-nitro-2H-chromene (S14161) was recently identified as a potent inhibitor of phosphoinositide 3-kinase (PI3K). In order to investigate the effects of its two enantiomers on tumor cell lines, we designed a novel synthesis for (R)-S14161 and (S)-S14161 using a chemical resolution and derivation strategy. The readily available 3-(tert-butyldimethylsilyloxy)-salicylaldehyde underwent a tandem oxa-Michael–Henry reaction with trans-4-fluoro-β-nitrostyrene in the presence of a catalytic amount of l-proline and triethylamine to give the 3-nitro-2H-chromene. Upon removal of the TBS protecting group, the resolution of the resulting racemic 2-(4-fluorophenyl)-8-hydroxy-3-nitro-2H-chromene was achieved via diastereomeric ester formation using (S)-(+)-α-methoxyphenylacetic acid as the derivatizing agent, followed by aminolysis. Finally, the ethyl ether formation of each enantiomer furnished (R)-S14161 and (S)-S14161 in enantiomerically pure forms. The absolute configurations of these chiral molecules were determined by a circular dichroism method. The two enantiomers showed no marked differences in inhibition of growth of human myeloma LP1 and OPM-2 cells. 相似文献
12.
A. A. Yavolovskii L. V. Grishchuk E. I. Bevzyuk Yu. E. Ivanov D. E. Stepanov S. M. Pluzhnik-Gladyr G. L. Kamalov 《Russian Journal of General Chemistry》2014,84(5):869-874
2-(2-Oxo-2-arylethylidene)-2,3-dihydropyrimidine-4(1H)-ones react with aromatic and heteroaromatic aldehydes to form the unsaturated ketones, whereas in the case of 3- and 4-benzaldehydes the corresponding trans-2-styrylpyrimidine-4(3H)-ones were obtained. A possible mechanism of hydrolytic cleavage of the product of condensation of 2-(2-oxo-2-phenylethylidene)-2,3-dihydropyrimidine-4(1H)-one with paraformaldehyde under acid catalysis and mechanochemical activation has been discussed. 相似文献
13.
Rudy D.P. Wadoux Xiaowei Lin Neil S. Keddie David O’Hagan 《Tetrahedron: Asymmetry》2013,24(12):719-723
A two-step synthesis of (R)- and (S)-[2H1]-fluoroacetate (sodium salts) in high enantioselectivity is reported. The synthesis is the development of a previous one in which the enantioselectivity has been increased from ~38% ee to >95% ee. The improvement in enantioselectivity applied Bio’s methodology, which involved a deoxyfluorination reaction with DAST on either enantiomer of [2H1]-benzyl alcohol, adding TMS-morpholine to the reaction. The additive promotes an SN2 inversion process, and suppresses a competing non-stereospecific SN1 reaction course, and as a result significantly improves the stereointegrity of the C–F bond formation. The intermediate [2H1]-benzyl alcohols, [2H1]-benzyl fluorides and the product [2H1]-fluoroacetates as their hexyl esters were separately assayed for their stereochemical integrity, using the Courtieu method. This method involved measuring their 2H NMR spectra in a chiral matrix of poly-γ-benzyl l-glutamate. The chiral assay demonstrated that there was no significant loss in stereointegrity during the deoxyfluorination reaction and showed that the enantiomers of [2H1]-fluoroacetate were generated with high enantiomeric purity (95% ee). 相似文献
14.
15.
This paper describes the selective syntheses of two cis-isomer-enriched cyclopentanone fragrances: (Z)-3-(2-oxopropyl)-2-(pent-2-en-1-yl)cyclopentanone (four steps, 62% overall yield, 67% cis) and Magnolione® (five steps, 60% overall yield, 55% cis). In addition, the asymmetric synthesis of (3aR,7aS)-5-methyl-2,3,3a,4,7,7a-hexahydro-1H-inden-1-one as well as (3a′R,7a′S)-5′-methyl-2′,3′,3a′,4′,7′,7a′-hexahydrospiro[[1,3]dioxolane-2,1′-indene] has been realized by an efficient kinetic resolution, which enables the selective synthesis of the 2S,3R-isomer-enriched 3 and 4. 相似文献
16.
Tushar S. Basu Baul Anup Paul Anthony Linden 《Journal of organometallic chemistry》2012,696(26):4229-4235
Three triorganotin(IV) complexes of composition R3SnLH (R = Me, Bu and Ph and LH = 2-[(E)-2-(4-hydroxy-3,5-dimethylphenyl)-1-diazenyl]benzoate) have been synthesized and characterized by 1H, 13C, 119Sn NMR, and IR spectroscopic techniques in combination with elemental analysis. The crystal structures of the carboxylate ligand HO2CC6H4{NN(C6H2-4-OH-3,5-(CH3)2)}-o in its neutral form and three triorganotin(IV) complexes, viz., polymeric (R3Sn[O2CC6H4{N–N(H)(C6H2-4-O-3,5-(CH3)2)}-o])n (R = Me (1) and Bu (2)) and monomeric Ph3Sn[O2CC6H4{N–N(H)(C6H2-4-O-3,5-(CH3)2)}-o] (3) complexes are reported. The polymeric complexes 1 and 2 exist as extended chains in which the LH-bridged Sn-atoms adopt a trans-R3SnO2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the phenoxide O atom of the next carboxylate ligand. The Sn atom in complex 3 has a distorted tetrahedral geometry. In all three complexes, the carboxylate ligand is in the zwitterionic form with the phenolic proton moved to the nearby azo nitrogen atom, in contrast to the free carboxylic acid ligand which is in the azo form. 相似文献
17.
《Journal of organometallic chemistry》2011,696(26):4229-4235
Three triorganotin(IV) complexes of composition R3SnLH (R = Me, Bu and Ph and LH = 2-[(E)-2-(4-hydroxy-3,5-dimethylphenyl)-1-diazenyl]benzoate) have been synthesized and characterized by 1H, 13C, 119Sn NMR, and IR spectroscopic techniques in combination with elemental analysis. The crystal structures of the carboxylate ligand HO2CC6H4{NN(C6H2-4-OH-3,5-(CH3)2)}-o in its neutral form and three triorganotin(IV) complexes, viz., polymeric (R3Sn[O2CC6H4{N–N(H)(C6H2-4-O-3,5-(CH3)2)}-o])n (R = Me (1) and Bu (2)) and monomeric Ph3Sn[O2CC6H4{N–N(H)(C6H2-4-O-3,5-(CH3)2)}-o] (3) complexes are reported. The polymeric complexes 1 and 2 exist as extended chains in which the LH-bridged Sn-atoms adopt a trans-R3SnO2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the phenoxide O atom of the next carboxylate ligand. The Sn atom in complex 3 has a distorted tetrahedral geometry. In all three complexes, the carboxylate ligand is in the zwitterionic form with the phenolic proton moved to the nearby azo nitrogen atom, in contrast to the free carboxylic acid ligand which is in the azo form. 相似文献
18.
S. A. Meshcheryakova 《Russian Journal of General Chemistry》2014,84(8):1539-1542
A new approach to prepare 2-chloroacetamides has been developed, based on the reaction of chloroacetyl chloride with excess of secondary amines. Alkylation of 6-methyl-1-(thiethan-3-yl)pyrimidine-2,4(1H,3H)-dione with the synthesized 2-chloroacetamides in the presence of potassium carbonate has afforded N 3-acetamido-substituted 6-methyl-1-(thiethan-3-yl)pyrimidine-2,4(1H,3H)-diones. 相似文献
19.
Samuel A. Sangokoya Gregory H. Robinson 《Journal of inclusion phenomena and macrocyclic chemistry》1988,6(3):263-266
The optically active quaternary ammonium salt (S)-(?)-α-[(C6H5)CH(CH3)N(CH3)3I] reacts with AlR3 to afford optically active organoaluminum based inclusion compounds, liquid clathrates, of the formula (S)-(?)-α-[(C6H5)CH(CH3)N(CH3)3][Al2R6I] (R=CH3, C2H5). Specific rotation ([α] 25 D ) for the Al(CH3)3 compound was determined to be ?13.19° while that for the Al(C2H5)3 analog was determined to be ?14.30°. There are 13.8 toluene molecules per anionic moiety for the trimethylaluminum based liquid clathrate while there are 15.0 toluene molecules per anion for the corresponding triethylaluminum inclusion compound. 相似文献
20.
Lin Jiang Peng Cao Yulei Zhang Xiezhong Xie 《Research on Chemical Intermediates》2012,38(9):2229-2235
The title compound 8-(2-(5-(4-methylphenyl)-2-thienyl)vinyl)l-10,10-dimethyl-10H-pyrido[1,2-a]indolium perchlorate (3) has been synthesized by cycloaddition and condensation reactions, and characterized by elemental analysis, IR, 1H NMR, and single-crystal X-ray diffraction. The crystal structure analysis exhibits that the molecule of 3 possesses good coplanarity, and the three rings (10H-pyrido[1,2-a]indolium, thienyl and phenyl) and vinyl moiety can make up a large conjugated system. Its UV-Vis and fluorescence spectra were measured, and found that it displays larger maximum absorptions and emission wavelengths in comparison with 8-(4-methylphenyl)vinyl analogue. 相似文献