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1.
《Tetrahedron: Asymmetry》2006,17(22):3063-3066
A stereocontrolled synthesis of the methyl ester of (2S)-3-amino-2-((4′S)-2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)propanoic acid from d-glyceraldehyde is described for the first time. This method involves the stereoselective Michael addition of the lithium salt of tris(phenylthio)methane to (S)-2,2-dimethyl-4-((E)-2-nitrovinyl)-1,3-dioxolane followed by hydrolysis of the resulting (4S)-2,2-dimethyl-4-((2′S)-3′-nitro-1′,1′,1′-tris(phenylthio)propan-2′-yl)-1,3-dioxolane to (2S)-methyl 2-((4′S)-2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-3-nitropropanoate, which was finally reduced to the target compound. A similarly stereocontrolled transformation of l-glyceraldehyde into (2R)-methyl 3-amino-2-((4′R)-2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)propanoate is also described.  相似文献   

2.
Four new meroterpenoids identified as (R)-4-((2,2-dimethylchroman-6-yl)methyl)-3-(4-hydroxyphenyl)-5-methoxyfuran-2(5H)-one (1), 1-(2,2-dimethylchroman-6-yl)-3-(4-hydroxyphenyl)propan-2-one (2), (R,E)-3-(2,2-dimethylchroman-6-yl)-4-hydroxy-5-((2-(2-hydroxypropan-2-yl)-2,3-dihydrobenzofuran-5-yl)methylene)furan-2(5H)-one (3), methyl (R)-2-(2-(2-hydroxypropan-2-yl)-2,3-dihydrobenzofuran-5-yl) acetate (4), along with nine known compounds (513) were isolated from a chemical-epigenetic culture of Aspergillus terreus OUCMDZ-2739 with 10 μM trichostatin A (TSA). Under the same condition without TSA, A. terreus OUCMDZ-2739 produced different compounds (1420), supporting that the chemical-epigenetic modification of fungi could enrich the chemodiversity of the fungal products. The cytotoxicity was observed for compound 8 against K562 cell, 9 against MCF-7 and K562 cells and 12 against MCF-7 cell with IC50 values of 9.5, 10.1, 13.0 and 8.5 μM, respectively. Compounds 3, 8 and 17 exhibited stronger α-glucosidase inhibition than 1-deoxynojirimycin and acarbose (positive controls) with IC50 values of 24.8, 1.2, 61.6, 191.7 and 555.1 μM, respectively. The enzyme kinetics study further indicated that compound 8 was an anticompetitive inhibitor with Ki value of 1.42 μM.  相似文献   

3.
Various Ru(L1)(L2) (1) complexes (L1 = 2,2′-bipyridines, 2,2′:6′,2″-terpyridines, 6-(4S)-4-phenyl-4,5-dihydro-oxazol-2-yl-2,2′-bipyridinyl or 2,2′-bipyridinyl-6-carboxylate; L2 = pyridine-2,6-dicarboxylate, pyridine-2-carboxylate or 2,2′-bipyridinyl-6-carboxylate) have been synthesized (or in situ generated) and tested on epoxidation of olefins utilizing 30% aqueous H2O2. The complexes containing pyridine-2,6-dicarboxylate show extraordinarily high catalytic activity. Based on the stereoselective performance of chiral ruthenium complexes containing non-racemic 2,2′-bipyridines including 6-[(4S)-4-phenyl-4,5-dihydro-oxazol-2-yl]-[2,2′]bipyridinyl new insights on the reaction intermediates and reaction pathway of the ruthenium-catalyzed enantioselective epoxidation are proposed. In addition, a simplified protocol for epoxidation of olefins using urea hydrogen peroxide complex as oxidizing agent has been developed.  相似文献   

4.
(2,4-Dimethoxybenzyl)hydrazine (DmbNHNH2) was utilized in the synthesis of Dmb-protected 4-((3,5-diamino-1H-pyrazol-4-yl)diazenyl)phenols. This unambiguous protection of the pyrazole endocyclic nitrogen atom enabled the preparation of amino-substituted 4-((3,5-diamino-1H-pyrazol-4yl)diazenyl)phenols that were inaccessible through direct substitution. The Boc group could be selectively cleaved in the presence of the Dmb group.  相似文献   

5.
Stereoselective diazotization of (S)-2-amino-2-phenyl acetic acid (L-phenyl glycine) (4) with NaNO2 in 6% H2SO4 in a mixture of acetone and water gave optically pure (S)-2-hydroxy-2-phenyl acetic acid (L-mandelic acid) (5). Esterification, gave (S)-2-hydroxy-2-phenyl acetic acid esters (6). The latter was treated with chloroacetyl chloride in the presence of triethylamine (TEA) in dichloromethane (DCM) to yield (S)-2-chloroacetyloxy phenyl acetic acid ester (2). In another sequence, the reaction of 2-(chloromethyl)-3-arylquinazolin-4(3H)-one (9) treated with N-Boc piperazine, followed by deprotection of the Boc group, to obtain 3-aryl-2-((piperazin-1-yl)methyl) quinazolin-4(3H)-one (3). Reaction of 2 with 3 in the presence of K2CO3 and KI gave the title compound, 2-(2-(4-((3,4-dihydro-4-oxo-3-arylquinazolin-2-yl)methyl)piperazin-1-yl) acetoyloxy)-2-phenyl acetic acid esters (1). The structures of all the new compounds obtained in the present work are supported by spectral and analytical data.  相似文献   

6.
Syntheses of dinucleotide analogs, (S,R) cis-(4-((4-amino-2-oxopyrimidin-1(2H)-yl)methyl)-1,3-dioxolan-2-yl)methyl (2R,3R,5R)-2-(hydroxymethyl)-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-tetrahydrofuran-3-yl hydrogen phosphate (5a) and (S,R) cis-(5-((4-amino-2-oxopyrimidin-1(2H)-yl)methyl)-1,3-oxathiolan-2-yl)methyl (2R,3R,5R)-2-(hydroxymethyl)-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-tetrahydrofuran-3-yl hydrogen phosphate (5b), were accomplished by the use of a new strategy. The use of phenyldichlorophosphate (Method A) as the coupling reagent was shown to possess superiority relative to the reported use of di(1H-benzo[d][1,2,3]triazol-1-yl)phenyl phosphonate (Method B).  相似文献   

7.
[Ni(L1)2](PF6)2 (3a, L1 = 3-(1-ethyl-1H-benzimidazol-2-yl)methyl)-1-((6-methylpyridin-2-yl)methyl)imidazolyl-idene), [Ni(L2)2(CH3CN)](PF6)2 (3b, L2 = 3-(1-ethyl-1H-benzimidazol-2-yl)methyl)-1-((6-methylpyridin-2-yl)-methyl)benzimidazolylidene), and [Hg(L1)2(CH3CN)2](PF6)2 (4) have been successfully prepared and fully characterized by NMR, ESI-MS spectroscopy, and X-ray diffraction analysis. The nickel complexes reveal a square-planar structure with two carbene ligands and benzimidazole groups at the cis configuration. The nickel complex 3b has been proved to be a highly efficient catalyst for Friedel-Crafts alkylation of indoles with β-nitrostyrenes at room temperature in moderate-to-excellent yields. The crystal packing structure of 4 shows that double-stranded 1D supramolecular chains are formed by inter-chain benzimidazole rings and pyridine rings face-to-face π-π stacking interactions.  相似文献   

8.
Photovoltaic performance of the organic solar cells(OSCs)based on 2-((5′-(4-((4-((E)-2-(5′-(2,2-dicyanovinyl)-3′,4-dihexyl-2,2′-bithiophen-5-yl)vinyl)phenyl)(phenyl)amino)styryl)-4,4′-dihexyl-2,2′-bithiophen-5-yl)methylene)malononitrile(L(TPAbTV-DCN))as donor and PC70BM as acceptor was optimized using 0.25 vol%high boiling point solvent additive of1-chloronaphthalene(CN),1,6-hexanedithiol(HDT),or 1,8-diodooctane(DIO).The optimized OSC based on L(TPA-bTVDCN)–PC70BM(1:2,w/w)with 0.25 vol%CN exhibits an enhanced power conversion efficiency(PCE)of 2.61%,with Voc of0.87 V,Jsc of 6.95 mA/cm2,and FF of 43.2%,under the illumination of 100 mW/cm2 AM 1.5 G simulated solar light,whereas the PCE of the OSC based on the same active layer without additive is only 1.79%.The effect of the additive on absorption spectra and the atomic force microscopy images of L(TPA-bTV-DCN)–PC70BM blend films were further investigated.The improved efficiency of the device could be ascribed to the enhanced absorption and optimized domain size in the L(TPA-bTV-DCN)–PC70BM blend film.  相似文献   

9.
Enantioselective syntheses of tert-butyl ((S)-2-(3,5-difluorophenyl)-1-((S)-oxiran-2-yl)ethyl)carbamate and ((S)-2-(3,5-difluorophenyl)-1-((R)-oxiran-2-yl)ethyl)carbamate are described. We utilized asymmetric syn- and anti-aldol reactions to set both stereogenic centers. We investigated ester-derived Ti-enolate aldol reactions as well as Evans’ diastereoselective syn-aldol reaction for these syntheses. We have converted optically active ((S)-2-(3,5-difluorophenyl)-1-((S)-oxiran-2-yl)ethyl)carbamate to a potent β-secretase inhibitor.  相似文献   

10.
2-Butyl-4-(methylseleno)-1-[[2′-(1H-tetrazol-5-yl)-1,1′-biphenyl-4-yl]methyl]-1H-imidazole-5-carboxylic acid (4) and 2-butyl-4-(phenylseleno)-1-[[2′-(1H-tetrazol-5-yl)-1,1′-biphenyl-4-yl]methyl]-1H-imidazole-5-carboxylic acid (5) have been prepared and tested for AT1 receptor antagonist properties. Both compounds proved to be potent AT1 receptor antagonists, with pKb estimates indicating that these selenides are very effective at blocking AT1 receptor mediated responses.  相似文献   

11.
A series of 2-(2-chloroquinolin-3-yl)-5-((aryl)benzylidene)-3-(4-oxo-2-phenylquinazolin-3(4H)-yl)thiazolidin-4-ones (V)1–12 have been synthesized. In order to establish optimization of different parameters of chemical transformation, that is the reaction pathway for each step and reaction conditions in the each step, in the present paper, different solvents and catalysts were used. The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, 1H NMR and 13C NMR spectral data. All the newly synthesized compounds were screened against various strains of bacteria and fungi.  相似文献   

12.
During the course of a research program aimed at identifying novel antileishmanial compounds, a multi-gram synthesis of N-(trans-4-((4-methoxy-3-((R)-3-methylmorpholino)-1H-pyrazolo[3,4-d]pyrimidin-6-yl)amino)cyclohexyl)-2-methylpropane-1-sulfonamide ((R)-1) was required. This letter describes optimisation of the reaction conditions and protecting group strategy for a key Buchwald-Hartwig coupling, delivering the required quantities of (R)-1, as well as further compounds in the series.  相似文献   

13.
In this study, a novel and convenient route for the construction of 5-((1H-1,2,4-triazol-1-yl)methyl)-1H-indoles (8) is presented starting from (1H-1,2,4-triazol-1-yl)methanol (5) and indolines (6) under 98% H2SO4 at room temperature for 4–24 h, followed by deacetylation and dehydrogenation. Based on this finding, a novel route to synthesize Rizatriptan starting from tryptamine was designed and accomplished with 48.5% overall yield in 6 steps. Compared with operational art, the new route afforded higher yield and more pure products requiring no chromatographic purification, which may further be applied in industrialization.  相似文献   

14.
Two d10 Schiff-base complexes, Zn2(L1)2(H2O)6 ? SO4 (1) and Cd(L2)2(H2O)4 (2) [HL1 = 3-((pyrid-3-yl)-methylene)aminobenzoic acid; HL2 = 4-((pyrid-3-yl)-methylene)aminobenzoic acid], have been synthesized and structurally characterized by elemental analyses, FT-IR spectra, and thermal studies, as well as single crystal X-ray diffraction. Complex 1 is a dinuclear macrocyclic structure with 22-membered rings and is assembled into a 3-D sandwich supramolecular network motif through H-bonding interactions; 2 is a mononuclear structure and is interlinked through H-bonding and π ··· π stacking contacts to generate another 3-D supramolecular network. Furthermore, fluorescent properties of the two complexes are also reported.  相似文献   

15.
Abstract

of 1,4-dihydro-4-oxo-1,8-naphthyridine-3-carbohydrazide (4) with substituted phenyl isothiocyanates (5) in ethanol under reflux for 30 min gave thiosemicarbazide derivatives 6, which on cyclization in 2N NaOH under refluxing conditions for 1 h resulted in 3-(5-mercapto- 4-phenyl-4H-1,2,4-triazol-3-yl)-1,8-naphthyridin-4(1H)-one (7). Alternatively, 7 could also be prepared from following sequence of reactions, i.e., 4 → 8 → 7. In another sequence of reactions, condensation of 7 with chloroacetic acid in dimethylformamide (DMF) and K2CO3 as a mild base at 120 °C for 2 h resulted in 2-((5-(1,4-dihydro-4-oxo-1,8-naphthyridin-3-yl)-4-phenyl-4H-1,2,4-triazol-3-yl)sulfanyl)acetic acid (10). The latter, on reaction with substituted o-phenylenediamine (11) in 6N HCl for 4 h yielded 3-(5-((1H-benzo[d]imidazol-2-yl)methylthio)-4-phenyl-4H-1,2,4-triazol-3-yl)-1,8-naphthyridin-4(1H)-one (12). Alternatively, 12 could also be prepared by reacting 7 with 13 in DMF and K2CO3 as a mild base at 120 °C for 2 h, followed by oxidation with H2O2 resulting in the corresponding sulfonyl derivatives 14.  相似文献   

16.
The reactions of zinc(II) chloride and two Schiff base ligands derived from rimantadine and 5-chlorosalicylaldehyde/4-methoxysalicylaldehydes, generated two novel complexes [Zn(L1)2Cl2] (I) and [Zn(L2)2Cl2] (II), where L1 = 2-((1-(1-adamantan-1-yl)ethyl)-iminomethyl)-4-chlorophenol, L2 = 2-((1-(1-adamantan-1-yl)ethyl)iminomethyl)-5-methoxyphenol. The complexes were characterized by the means of IR, 1H NMR, elemental analysis, molar conductance and thermal analysis. A single-crystal X-ray diffraction analysis reveals that both complexes crystallize in orthorhombic system, space group Fdd2 for I and Pbcn for II. In two complexes crystals, each asymmetric unit consists of one zinc(II) ion, two corresponding Schiff base ligands and two chlorine atoms; the central zinc atom lies on a twofold rotation axis and is four-coordinate via two chlorine atoms and two oxygen atoms from the Schiff base ligands, forming a distorted tetrahedral geometry.  相似文献   

17.
《Tetrahedron: Asymmetry》2014,25(16-17):1205-1208
An improved and practical synthesis of tert-butyl ((4R,6R)-6-aminoethyl-2,2-dimethyl-1,3-dioxan-4-yl)acetate 3 has been developed for supplying this key chiral side-chain of atorvastatin by using a Blaise reaction of (S)-4-chloro-3-((trimethylsilyl)oxy)butanenitrile 7 and the Raney Ni catalyzed hydrogenation of tert-butyl 2-((4R,6R)-6-(-2-oximeethyl)-2,2-dimethyl-1,3-dioxan-4-yl)acetate 12 as the key steps. This nine-step route from (R)-epichlorohydrin afforded the target compound in 55% overall yield of high chemical and enantiomeric purity.  相似文献   

18.
A series of triazepane derivatives such as (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-ones (7, 13a-p) and (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-trifluorophenyl)butan-1-ones (17a-e) was synthesized and evaluated for their ability to inhibit dipeptidyl peptidase IV (DPP-IV) enzyme. Compounds with the acid moiety were found to be potent inhibitors of DPP-IV without inhibiting CYP 3A4. Among them, compound 13p ((R)-4-[1-acetyl-2-{3-amino-4-(2,4,5-trifluorophenyl)butanoyl-1,2,5-triazepan-5-carbonyl}benzoic acid]) showed a good in vitro activity without inhibiting CYP.  相似文献   

19.
To study the diverse coordination modes of the H2btib,three new coordination architectures,namely, [Ag(Hbtib)CH3CN]n(1),)[Ag(Hbtib)]n(2) and[Pb(btib)(CH3OH)2]n(3)(where H2btib=4-((2-butyl-5-(2- carboxy-3-(thiophen-2-yl)prop-1-enyl)-1H-imidazol-1-yl)methyl)benzoic acid) have been synthesized and characterized by elemental analysis,IR spectrum and single-crystal X-ray diffraction.Complex 1 exhibits 1D single chain structure,while 2 shows 1D double metal chain motif,and 3 features a 2D layer topology.Also,1,2 and 3 display strong emission band in the solid state at room temperature.  相似文献   

20.
A series of novel quinazolinone derivatives containing a 1,2,4-triazolylthioether moiety were synthesised and their antimicrobial activities were evaluated. All the target compounds were characterised by 1H NMR, 13C NMR, ESI-MS, IR and elemental analyses. The single crystal structure of 3-((5-((2-fluorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIi) was also determined. The preliminary bioassays indicated that some of the target compounds possessed good antimicrobial activities. For example, 3-((4-phenyl-5-((4-(trifluoromethyl)benzyl)thio)-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIs) exhibited the best inhibitory effect against Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri with the half-effective concentration (EC50) values of 47.6 μg mL?1 and 22.1 μg mL?1, respectively, which were superior to the commercial bactericide, bismerthiazol. Meanwhile, 3-((5-((4-chlorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIh) exhibited better fungicidal activities against Pellicularia sasakii and Colletotrichum capsici at the concentration of 50 μg mL?1, in comparison with the commercial fungicide, hymexazol.  相似文献   

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