手性1，4-二胺构建的双核铜[2+2]席夫碱大环化合物：制备和催化研究

Dinuclear copper(Ⅱ) complexes of [2+2] macrocyclic Schiff bases have been prepared from chiral 1,4-diamines using sodium ions as template. Catalytic investigation on the titled complexes has been carried out on model reactions (asymmetric sulfoxidation and asymmetric oxidative-coupling reactions).     

SYNTHESIS, CHARACTERIZATION AND SELECTIVITY STUDIES OF POLY(ACRYLAMIDE) INCORPORATING SCHIFF BASES

Three novel polymers incorporating Schiff bases,derived from condensation reactions of poly(acrylamide) with 5- chloro-2-hydroxybenzaldehyde,5-bromo-2-hydroxybenzaldehyde and 5-methyl-2-hydroxybenzaldehyde,have been synthesized,and their Cu(Ⅱ) and Ni(Ⅱ) complexes have been prepared.The ~1H-NMR signals of the—CH=N—and—NH_2 groups have been utilized to determine the relative abundances of Schiff base and acrylamide groups in the polymers containing Schiff bases.Poly(acrylamide) incorporating Schiff bases a...     

Synthesis and Crystal Structure of [Ni(II)(L)(py)_3]·(py)

1 INTRODUCTION Schiff bases and their metal complexes are useful reagents in organic synthesis[1], and they have exhi- bited some biological activities as anticancer and antitumor drugs[2]. The crystal structures and physi- cal and chemical properties of many Schiff bases and their transition metals complexes have been re- ported[3~5]. Further interest in the coordination che- mistry of nickel(II) arises from the role of these complexes in several catalytic reactions, such as electrocat…     

Palladium-catalyzed asymmetric allylic C–H alkylation of 1,4-dienes and glycine Schiff bases

A highly regio-and enantioselective allylic C–H alkylation of 1,4-dienes with glycine Schiff bases has been established by chiral palladium-phosphoramidite catalysis. This reaction can proceed under mild conditions and tolerate a wide scope of 1,4-dienes,delivering structurally diverse chiral β-branched α-amino acid surrogates in moderate to high yields and with high levels of regio-, Z/E-, diastereo-and enantioselectivities.     

Synthesis,spectral studies,thermal behavior,and antibacterial activity of Ni(Ⅱ),Cu(Ⅱ),and Zn(Ⅱ) complexes with an ONO tridentate Schiff base

Three new transition metal complexes have been synthesized with a Schiff base,3-(2-hydroxy-5-chlorophenylimino)-l,3- diphenylpropen-1-one.In all complexes Schiff base is completely deprotonated and coordinated to metal as tridentate ligand via phenolic and enolic oxygens and imine nitrogen.Thermal decomposition of the complexes has been studied by thermogravimetry. The in vitro antibacterial activity of Schiff bases and their complexes has been evaluated and compared with the standard drugs.     

Synthesis and Structure Characterization of N-Phenyl-（2S）-hydroxy-3-[（2-hydroxybenzylidene）amino]propionamide

1 INTRODUCTION Schiff bases can be conveniently prepared from the corresponding aldehyde and primary amine, which, as multidentate ligands, have already received great attention. Many metal complexes of this kind of ligands have been used successfully in various re- actions, such as Diels-Alder and hetero-Diels-Alder reactions[1], kinetic resolution of racemic epoxides[2], and Nozaki-Hiyama-Kishi (NHK) reaction[3]. Recen- tly Berkessel et al. have reported that the Cr- complex of sal…     

Syntheses,Crystal Structures,and Electrochemical Properties of Dehydroabietic Acid-based Schiff Bases

Two Schiff bases(DAMBA-Fc and DAA-Fc) derived from dehydroabietic acid have been successfully synthesized and characterized by means of FT-IR, elemental analysis, HRMS, and NMR spectroscopy. The crystal structure of DAA-Fc can be determined by single-crystal X-ray diffraction. The compound is of monoclinic system, space group P2_1 with a = 10.7379(6), b = 7.5004(4), c = 33.3294(18) ?, β = 97.996(3)o, Z = 4, V = 2658.2(3) ?~3, M_r = 481.48, D_c = 1.203 g/cm~3, S = 1.034, μ = 0.585 mm-1, F(000) = 1032, the final R = 0.0566 and wR = 0.0701 for 5645 observed reflections(I 2σ(I)). In addition, cyclic and differential pulse voltammogram techniques have been applied to differentiate the redox properties of the aromatic-and aliphatic-connected Schiff bases DAMBA-Fc and DAA-Fc, respectively.     

New cohort of optically active nanostructure poly(amideimide)s: Production and properties

Novel aromatic-aliphatic poly(amide-imide)s containing chiral units in the main chain and hydroxyl benzamide units in the side chain have been obtained from the step-growth polymerization of 3,5-diamino-N-(4-hydroxyphenyl) benzamide(2) with different chiral diacid chlorides(1a-1e).Theoretical calculations were done by means of computational chemistry methods to narrate the stable conformation and orientation of each diacid chloride monomers under reaction conditions.These polymers were characterized by conventional techniques.The resulting polymers show good thermal stability.Other physical properties of polymers including crystallinity,inherent viscosity and morphological characteristics were also studied.     

Synthesis and characterization of novel chiral diporphyrins and their dimetal complexes

Reaction of chiral 2,2'-biamino-1,1'-binaphthalene (R or 5) with monosubstituted porphyrin 1b and 2b-c afforded novel chiral diporphyrins 3a-c and 4a-c. Their dimetal complexes [(M)2DiPor] have also been prepared. Both structures have been identified by MS, IR, UV-visible, 1H NMR spectra and elemental analysis. These novel chiral compounds show very high optical activities.     

The Synthesis and Anion Binding of Novel Cholic Acid-based Molecular Clefts Containing Unsymmetrically Disubstituted Urea Unit

A novel type of chiral molecular clefts consisting of a rigid deoxycholic acid methyl ester backbone and chiral unsymmetrically disubstituted urea side chain have been designed and synthesized. All these new receptors 3a-c and the corresponding key intermediates la-c and 2a-c are new compounds, their structures were confirmed by ^1HNMR, IR, MS spectra and elemental analysis. These molecular clefts showed binding ability for halide anions.     

Synthesis,structural characterization and antibacterial activity of diorganotin(Ⅳ) complexes with ONO tridentate Schiff bases containing pyridine ring

Five organotin（IV） complexes,were obtained by reaction of SnR₂Cl₂（R = Ph,Me,Bu） with ONO donor Schiff bases.The synthesized complexes have been investigated by elemental analysis and IR,¹H NMR,and ¹¹⁹Sn NMR spectroscopy.These data show that the Schiff base acts as a tridentate dianionic ligand and coordinates via the imine nitrogen and two oxygen atoms.The Xray crystallography of complex 4 shows a dimeric structure for this molecule.The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive（Bacillus subtilis and Staphylococcus aureus） and Gram-negative （Escherichia coli and Pseudomonas aeruginosa） bacteria and compared with the standard antibacterial drugs.     

Asymmetric Addition of Diethylzinc to Aldehydes Catalyzed by Chiral γ_Amino Alcohols

Although the asymmetric additions of diethylzinc to aldehydes have been extensively studied in the presence of chiral catalyst, most of the chiral ligands tested are b-amino alcohols1. In this report, the synthesis of chiral gamino alcohols 1-4 from the reaction of (+)-camphor and (-)-menthone with 2-lithiomethyl-6-methyl-pyridine or 2-picolly- lithium2, which give a single diasteromer as determined by 1H NMR with high yields (Scheme 1)3, and their application in the enantioselective additio…     

SYNTHESIS OF 1-SUBSTITUTED-BENZENESULFO-NYL-3-(4'''',6''''-DISUBSTITUTED-s-TRIAZIN.2''''-YL)-1,3,2-DIAZAPHOSPHOLIDINES AND THEIR STRUCTURAL ANALYSES

The reaction of N-substituted-benzenesulfonyl-N'-(4,6-disubstituted-s-triazin-2-yl)-ethylene diamines with tri(dialkylamine)phosphine has been studied and the cyclic products have been obtained by one-pot reaction. It was found from ~1H NMR and ~(13)C NMR analyses that the single bond rotation between the nitrogen atom 3 in the 1,3,2-diazaphospholidines and the carbon atom 2 in the s-triazine was hindered at room temperature, which was further confirmed by X-ray diffraction results. The most stable conformation of the phosphorous heterocycle is envelope-form. From the bond length and the hybridization of the nitrogen atom outside the ring, it was deduced that there was a certain contribution of dπ-pπ bond between P and N atoms.     

A practical synthesis of novel hydroxyl-substituted macrocyclic tri-,tetra- and hexa-amines

Macrocyclic tri- and tetra-amines containing a hydroxyl group in the ring have been prepared in moderate yields by a 1:1 cyclocondensation of l,3-dichloro-2-propanol with the disodium salt of N-tosylated diethylenetriamine and triethylenetetraamine.In the case of condensation of 1,3-dichloro-2-propanol with the disodium salt of N-tosylated diethylenetriamine,the 2:2 cyclocondensation product,dihydroxyl macrocyclic hexaamine,was also isolated.     

Syntheses,Crystal Structure and Thermal Analyses of the Complex of Copper(Ⅱ) with N,N'-Bis-Sal icy1idene-Ethyl enediamine(H_2Salen)

Introduction In recent years, the syntheses, properties and applications of the complexes of transition-metal ions with Schiff bases have been a very interesting subject in coordination chemistry. It has been clearly stated that some of them have certain antitumor     

Synthesis of 2-En-l-one-ebelactonyl Benzoates of Territrem B Analogues from Jujubogenin

Two series of territrem B analogues (10a-10c and 18) have been designed and synthesized from jujubogenin 5a which was prepared from jujubogenin glycosides 5b obtained from the leaves of Zizyphusjujuba. The structures of the new compounds were confirmed by 1H-,13C-NMR and MS data. Compounds 10c and 18 showed weak inhibitory effect on AChE at 10^-4 mol/E.     

Synthesis and Biological Activities of Substituted Triazolethione Schiff Base

Six novel Schiff bases have been synthesized by the condensation reaction of 4-amino-5-（4-pyridyl）-2,4-dihydro-1,2,4-triazole-3-thione with various benzaldehydes. The sfructures of the compounds have been confirmed by ^1H NMR, IR and elemental analysis. The preliminary bioassay indicated that the title compounds possessed good fungicidal activities to several vegetable pathogens.     

Preliminary Screening of Non-platinum Complexes of Schiff Bases as Antitumour Agents Using Fluorimetry

Based on the consistency of the in vivo and in vitro interactions of drugs with DNA, a fluorimetric method has been developed as a new in vitro method for preliminary screening of antitumour agents. This method was tested using Schiff bases synthesized from salicylaldehyde with 1-alanine, 1-asparagine and 1-histidine, and complexes of these Schiff bases with Cu(Ⅱ), Zn(Ⅱ), Ni(Ⅱ) and Sn(Ⅳ) as potential antitumour agents.The study of the interaction of the complexes with DNA by a fluorescence probe ethidium bromide (EthBr)-DNA system indicated the parallelism between the binding constants and antineoplastic ratios. The relationship between structure and antitumonr activity was investigated.     

Synthesis and Antimicrobial Studies of Novel Billogical Heterocycles

The synthetic route of sildenafil promoted us to synthesize new object molecules. New analogues containing a 4-thiazolidinone ring bonded to the phenyl moiety at the 2-position, 7-(substituted anilino)-6-fluoro-2-(p-meth- oxy-m-{[2-(p-hydroxyphenyl)-4-oxo-1,3-thiazolidin-3-yl]aminocarbonyl}phenylsulfonamido)benzothiazoles (4a—4l) have been synthesized by cyclization with thioglycollic acid of Schiff bases 3a—3l from corresponding 7-(substituted anilino)-6-fluoro-2-(p-methoxy-m-hydrazinocarbonyl phenylsulfonamido)benzothiazoles (2a—2l). Compounds 2a—2l in turn were prepared by dehydroxyhalogenation followed by condensation with hydrazine hydrates of acids 1a—1l. Compounds 1a—1l in turn were prepared by chlorosulfonation of o-methoxy benzoic acid followed by condensation with 6-fluoro-7-(substituted anilino)-2-aminobenzothiazoles. Final compounds have been characterized by their elemental analysis, IR, NMR and mass spectra. All the synthesized compounds have been screened for their antimicrobial activities. Some of them showed good activities.     

Synthesis and Crystal Structure of Bis-{N-[2-(6-ethylpyridyl)]-salicylideneiminato} Cobalt(Ⅱ)

1 INTRODUCTION The Schiff bases derived from salicylaldehyde and 2-aminopyridine derivatives have been used as potentially terdentate ligands[1]. Yamada and Yam- anouchi have synthesized the type of ML2nH2O complexes (M = CoⅡ, NiⅡ, CuⅡ, ZnⅡ or PdⅡ)[