- Synthesis of α-(alkoxysilyl)acetic esters. A route to 1,2 diols
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An easy route to α-(alkoxysilyl)acetic esters and their utilization is described. It involves a two-step sequence carried out in one pot Rhodium catalyzed Si-H insertion of a carbenoid, generated by decomposition of N2CHCO2Et, followed by a nucleophilic attack onto the Si-Cl bond by an alcohol. Alkylation of the title esters, reduction of the ester function and finally oxidation of the C-Si bond provide a facile entry to 1,2 diols.
- Andrey, Olivier,Landais, Yannick,Planchenault, Denis,Weber, Valery
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- Stereoselective synthesis of cis-bis-β-lactams linked with an ethylene bridge
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An efficient synthesis of (±)-cis-bis-β-lactams (5 and 6) via cycloaddition reaction of bisimines (3a-c) with acid chlorides (4) in the presence of triethylamine in very good yield is described. (C) 2000 Published by Elsevier Science Ltd.
- Karupaiyan,Puranik,Deshmukh,Bhawal
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- A new macrocyclic heterobinuclear Cu(II)-Zn(II) complex: synthesis, crystal structure, phosphate hydrolysis, and DNA binding studies
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A new macrocyclic heterobinuclear Cu(II)-Zn(II) complex was synthesized and characterized by elemental analysis, FT-IR, ES-MS, and single-crystal X-ray diffraction. Five-coordinate geometry for the new complex is proposed. The copper…zinc distance bridged by two phenolic oxygens and a acetate ligand is 2.9508 ?. The phosphate ester hydrolysis activity and the DNA binding ability of the complex were studied. The results showed that the present complex has an efficient catalytic activity of phosphoester bond cleavage. The catalytic rate constant kcat for the hydrolysis of 4-nitrophenyl phosphate disodium salt hexahydrate (pNPP) by the synthesized complex is 2.69 × 10?4 s?1 and 105 times faster than the spontaneous hydrolysis of the phosphate monoester. The complex shows a good binding ability to calf thymus (CT-DNA) and the corresponding binding constant is 1.9 × 105 M?1. The linear Stern-Volmer quenching constant obtained by the fluorescent spectroscopic is 6.3 × 104 M?1.
- Kou, Huizhi,Wang, Yang,Ding, Peipei,Li, Jianfen,Shi, Baoxian
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- An efficient electrochemical method for the synthesis of quinoxaline-dione derivatives from oxidation of catechols in the presence of N1, N 2-dibenzylethane-1,2-diamine
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A series of 1,4-dibenzyl-1,2,3,4-tetrahydroquinoxaline-6,7-dione derivatives (6a-6c) were electrosynthesized. In the present work, electrochemical oxidation of catechols 1a-1d in the presence of the N 1,N2-dibenzylethane-1,2-diamine (3) as a nucleophile, has been studied in aqueous solutions using cyclic voltammetry and controlled-potential coulometry (CPC) methods. Various parameters such as the applied potential, pH of the electrolytic solution, cell configuration and also purification techniques, were carried out to optimize the yields of corresponding products. New quinoxaline-6,7-dione derivatives were synthesized in excellent yield using an electrochemical procedure coupled with a Schiff base as a facile, efficient and practical method.
- Dowlati, Bahram,Nematollahi, Davood,Othman, Mohamed Rozali
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- Synthesis and supramolecular features of hybrid POM/onium solid-state assemblies
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Polyoxomolybdate-based organic-inorganic hybrid architectures were synthesised and characterised by X-ray crystallography. The supramolecular assemblies present rows of metallic clusters H-bonded by ammonium cations, with a 1:2 molybdate/ammonium ratio. The organic moieties of the ammonium cations establish hydrophobic contact among them such as van der Waals, C-Hπ and ππ interactions that stabilise the supramolecular architectures. In particular, for compound 5 the n-alkyl tails pack closely together giving a lipid-like bilayer. In compound 6, the aromatic phenyl rings of the organic cation allow the stabilisation of the supramolecular architecture by C-Hπ and ππ interactions. Regarding the X-ray structure of the compound 11, the tetraanionic octa-molybdate [Mo8O26]4- cluster is surrounded by four ethyl-triphenyl-phosphonium cations. Running along the b-axis open channels are occupied by DMF solvent molecules. Interestingly, a soaking experiment in n-pentane with the corresponding crystals of compound 11 afforded to a crystal structure very different from the native one. Van der Waals, C-Hπ and ππ interactions between large organic moieties are fundamental in the stabilization of hybrid organic-inorganic POM architectures.
- Talotta, Carmen,Rubino, Luca,Gaeta, Carmine,Capitelli, Francesco,Saviano, Michele,Brancatelli, Giovanna,Geremia, Silvano,Vasca, Ermanno,Neri, Placido
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- Synthesis and antitubercular activity of ferrocenyl diaminoalcohols and diamines
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A total of 21 ferrocenyl and benzyl diaminoalcohols and diamines were synthesized and evaluated against Mycobacterium tuberculosis H37Rv. Interestingly, ferrocenyl diamines exhibit better activities than ferrocenyl diaminoalcohols.
- Andrianina Ralambomanana, Dimby,Razafimahefa-Ramilison, Dorothee,Rakotohova, Andry Clement,Maugein, Jeanne,Pelinski, Lydie
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- Synthesis of single-component urethane sealants
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Single-component urethane sealing formulations with aldimines as cross-linking agents were developed. The temperature dependence of the curing time of the sealants was examined. The influence of the -CH=N-/-NCO ratio and of fillers (industrial carbon and chalk) on their physicochemical properties was studied.
- Elchueva,Aristova,Bortnikov,Tabachkov
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- Synthesis and spectral data of new 1,2-bis-(2-hetaryl-4-oxothiazolidin-3- yl)ethanes and 1,4-bis-(2-hetaryl-4-oxothiazolidin-3-yl)butanes
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New α,ω-bis-(2-hetaryl-4-oxothiazolidin-3-yl)alkanes were prepared via a common two step procedure using N,N-bis-hetarylidenamines condensation with α-mercaptoacetic acid. The used bis-aldimines were obtained from reaction between ethylenediamine or putrescine and benzaldehyde or the isomeric pyridinecarboxyaldehydes. The bis-(2-phenyl-4-oxothiazolidin-3-yl) alkanes were prepared by one-pot three component reaction of diamine, aldehyde and α-mercaptoacetic acid under very mild conditions.
- Kouznetsov, Vladimir V.,Amado, Diego F.,Bahsas, Ali,Amaro-Luis, Juan
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- Synthesis and study of N, N' -(ethane-1,2-diyl)bis(1-phenyl methanimine) and their complex derivative with in-vivo and in-vitro Bacterial biological study
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In this research, the synthesis and biological activity evaluation of N, N'-(ethane-1,2-diyl)bis(1-phenyl methanimine) as Schiff base with Zinc (II) dithiocarbamate complex are successfully reported. The suggested geometry around zinc ion centre was determined using selected unique physicochemical and spectroscopic techniques. These include melting point, conductance, FTIR, UV-Vis, mass spectroscopy and 1H-NMR spectroscopy. The analytical as well as the spectroscopic characterization data proves the formation of zinc complex with general formula [Zn(L)]2 and the complex of this ion is adopting tetrahedral geometry about the metal centre. Furthermore, the present study was carried out to evaluate antibacterial activity of obtained Schiff base ligand and Zn complex against five strains of bacteria (Staphylococcus aureus, Escherichia coli, Lacto bacillus, Klebsiella Pneumonae,and Salmonella typhi). The results of antimicrobial screening suggest that Schiff bases can show a considerable activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Salmonella typhi while Zn-complex was reported to be more active against all bacterial strains which is used in this test. The antibacterial activity of each compound has been examined practically (in vivo) by treating burns rats infected with tested bacteria (Staphylococcus aureus and Salmonella typhi), the results have shown signs of good recovery at short time if it compared with antibiotic Ofloxacin (OFX) used at the same time. And the number of bacteria was reduced significantly (P 0.001) during the treatment days. Furthermore, the results showed that Zn-complex is effective in treating various skin conditions; it is preferable to use it in the treatment of pathological injuries and against other skin infections.
- Alfahdawi, Aeed S.,Al-Sorchee, Sawsan M.,Saleh, Suhab E.,Saleh, Marwan M.
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p. 2879 - 2888
(2021/05/28)
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- In-vitro antimicrobial screening and coordination behavior of metals based bidentate compounds
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By condensing ethylene-1,2-diamine with different aldehydes such as benzaldehyde, 4-chloroacetophenone and 2-chlorobenzaldeyhde within 1:2 molar ratio, resulted new series of Schiff base ligands (L1)-(L3) containing bidentate nitrogen atom. Their metal complexes were synthesized by coordinating the ligands with transition metals as Co(II), Cu(II), Ni(II) and Zn(II) and exhibited octahedral geometry. Their characterization was done with the help of spectral, physical and analytical analysis. Spectral and elemental analysis of all bidentate ligands and their corresponding 3d-metal chelates was consistent with their proposed structures, signifying the high purity of these compounds. For in-vitro studies, these metal complexes along their ligands were screened against the six bacterial strains; Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Streptococcus faecalis. Six fungal strains; Aspergillus niger, Trichophyton mentogrophytes, Epidermophyton floccosum, Trichophyton schoenleinii, Microscopum canis and Fusarium culmorum were used to study antifungal activity of the compounds. Bioactivity results exhibited that metal complexes showed higher antimicrobial potential as compared with their corresponding ligands. The enhanced activity resulted due to chelation that decreases the polarity of metal ions by complexing with bidentate ligands.
- SUMRRA, SAJJAD HUSSAIN,IMRAN, MUHAMMAD,IBRAHIM, MUHAMMAD,AMBREEN, SABAHAT,MEHMOOD, RASHAD,ASSIRI, MOHAMMED ABDULLAH,IRFAN, AHMAD
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p. 5057 - 5062
(2021/03/26)
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- Design, synthesis and biological evaluation of Schiff’s base derivatives as multifunctional agents for the treatment of Alzheimer’s disease
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A series of Schiff’s base derivatives was rationally designed, synthesized, and evaluated as multi-function agents for the treatment of Alzheimer’s disease (AD). The results revealed that compound 3b was a novel multifunctional agent. It acted as a highly selective monoamine oxidase-B inhibitor (IC50 = 8.4 nM), which was explained by the docking study. Compound 3b also was an antioxidant agent (2.3 eq) and could significantly inhibit self-induced Aβ1-42 aggregation (31.8%). Meanwhile, compound 3b was a selective metal chelator and could inhibit Cu2+-induced Aβ1-42 aggregation (62.3%). Furthermore, compound 3b presented good neuroprotective effects on H2O2-induced PC12 cell injury. More importantly, compound demonstrated good blood brain barrier permeability and druglike properties. Therefore, compound 3b, a promising multi-targeted active molecule, offers an attractive starting point for further study in the drug-discovery process against AD.[Figure not available: see fulltext.].
- Shi, Jian,Zhou, Yi,Wang, Keren,Ma, Qinge,Wei, Rongrui,Li, Qingfeng,Zhao, Yiyang,Qiao, Zhanpin,Liu, Shuang,Leng, Yumin,Liu, Wenmin,Sang, Zhipei
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p. 624 - 634
(2020/11/30)
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- Nitrogen-modified graphene as a metal-free carbocatalyst for the solvent-free oxidative homo- and heterocoupling of amines
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In this study, graphene oxide (GO) has been prepared using Hammers’ method and the produced GO was converted to nitrogen-modified GO (NGO) using hydrothermal reaction with ammonia and hydrazine. The morphology of the product was confirmed with FESEM images and XRD, TEM, Raman, TGA, EDS, BET and FTIR analyses were employed to study the structure and properties of the product. The produced NGO has been employed as a catalyst for oxidative coupling of amines to imines. The reaction was carried out at 110?°C, using 4 wt% of catalyst (versus the used amine), oxygen gas as oxidative agent, solvent-free condition in 4?h with 80% yield. To determine the versatility of the reaction, different derivatives of amines such as benzylamine, phenyl hydrazine, aniline, ethylenediamine, ethanol amine and homoveratrylamine have been examined in this reaction and successfully converted to the related imines via heterocoupling reactions. Finally, the recyclability of the reaction was investigated and the results showed only 10% decreasing in the yield after 6 runs.
- Ganbari, Alireza,Tavakol, Hossein
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- Rapid Thermodynamically Stable Complex Formation of [nat/111In]In3+, [nat/90Y]Y3+, and [nat/177Lu]Lu3+ with H6dappa
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A phosphinate-bearing picolinic acid-based chelating ligand (H6dappa) was synthesized and characterized to assess its potential as a bifunctional chelator (BFC) for inorganic radiopharmaceuticals. Nuclear magnetic resonance (NMR) spectroscopy was employed to investigate the chelator coordination chemistry with a variety of nonradioactive trivalent metal ions (In3+, Lu3+, Y3+, Sc3+, La3+, Bi3+). Density functional theory (DFT) calculations explored the coordination environments of aforementioned metal complexes. The thermodynamic stability of H6dappa with four metal ions (In3+, Lu3+, Y3+, Sc3+) was deeply investigated via potentiometric and spectrophotometric (UV-vis) titrations, employing a combination of acidic in-batch, joint potentiometric/spectrophotometric, and ligand-ligand competition titrations; high stability constants and pM values were calculated for all four metal complexes. Radiolabeling conditions for three clinically relevant radiometal ions were optimized ([111In]In3+, [177Lu]Lu3+, [90Y]Y3+), and the serum stability of [111In][In(dappa)]3- was studied. Through concentration-, time-, temperature-, and pH-dependent labeling experiments, it was determined that H6dappa radiolabels most effectively at near-physiological pH for all radiometal ions. Furthermore, very rapid radiolabeling at ambient temperature was observed, as maximal radiolabeling was achieved in less than 1 min. Molar activities of 29.8 GBq/μmol and 28.2 GBq/μmol were achieved for [111In]In3+ and [177Lu]Lu3+, respectively. For H6dappa, high thermodynamic stability did not correlate with kinetic inertness-lability was observed in serum stability studies, suggesting that its metal complexes might not be suitable as a BFC in radiopharmaceuticals.
- Jaraquemada-Pelaéz, Mariá De Guadalupe,Kostelnik, Thomas I.,Kubeil, Manja,Orvig, Chris,Southcott, Lily,Stephan, Holger,Wagner, Hannah K.,Wang, Xiaozhu
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p. 7238 - 7251
(2020/06/08)
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- Synthesis of Imines via Reactions of Benzyl Alcohol with Amines Using Half-Sandwich (η6-p-cymene) Ruthenium(II) Complexes Stabilised by 2-aminofluorene Derivatives
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A new class of half-sandwich (η6-p-cymene) ruthenium(II) complexes supported by 2-aminofluorene derivatives [Ru(η6-p-cymene)(Cl)(L)] (L?=?2-(((9H-fluoren-2-yl)imino)methyl)phenol (L1), 2-(((9H-fluoren-2-yl)imino)methyl)-3-methoxyphenol (L2), 1-(((9H-fluoren-2-yl)imino)methyl)naphthalene-2-ol (L3) and N-((1H-pyrrol-2-yl)methylene)-9H-fluorene-2-amine (L4)) were synthesized. All compounds were fully characterized by analytical and spectroscopic techniques (IR, UV–Vis, NMR) and also by mass spectrometry. The solid state molecular structures of the complexes [Ru(η6-p-cymene)(Cl)(L2)], [Ru(η6-p-cymene)(Cl)(L3)] and [Ru(η6-p-cymene)(Cl)(L4)] revealed that the 2-aminofluorene and p-cymene moieties coordinate to ruthenium(II) in a three-legged piano-stool geometry. The synthesized complexes were used as catalysts for the dehydrogenative coupling of benzyl alcohol with a range of amines (aliphatic, aromatic and heterocyclic). The reactions were carried out under thermal heating, ultrasound and microwave assistance, using solvent or solvent free conditions, and the catalytic performance was optimized regarding the solvent, the type of base, the catalyst loading and the temperature. Moderately high to very high isolated yields were obtained using [Ru(η6-p-cymene)(Cl)(L4)] at 1?mol%. In general, microwave irradiation produced better yields than the other two techniques irrespective of the nature of the substituents.
- Vinoth, Govindasamy,Indira, Sekar,Bharathi, Madheswaran,Durgadevi, Anandhan,Abinaya, Ravikumar,Alves, Luis G.,Martins, Ana Margarida,Bharathi, Kuppannan Shanmuga
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- Design and application of diimine-based copper(i) complexes in photoredox catalysis
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Structurally different bis(imino)copper(i) complexes were prepared in a highly modular manner and utilized as copper-based photocatalysts in the ATRA reactions of styrenes and alkyl halides. The new photocatalysts showed good catalytic activity and ensured efficient chemical transformations.
- F?ldesi, Tamás,Sipos, Gellért,Adamik, Réka,Nagy, Bálint,Tóth, Balázs L.,Bényei, Attila,Szekeres, Krisztina J.,Láng, Gyz G.,Demeter, Attila,Peelen, Timothy J.,Novák, Zoltán
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supporting information
p. 8343 - 8347
(2019/09/30)
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- Design, synthesis and evaluation against Mycobacterium tuberculosis of azole piperazine derivatives as dicyclotyrosine (cYY) mimics
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Three series of azole piperazine derivatives that mimic dicyclotyrosine (cYY), the natural substrate of the essential Mycobacterium tuberculosis cytochrome P450 CYP121A1, were prepared and evaluated for binding affinity and inhibitory activity (MIC) against M. tuberculosis. Series A replaces one phenol group of cYY with a C3-imidazole moiety, series B includes a keto group on the hydrocarbon chain preceding the series A imidazole, whilst series C explores replacing the keto group of the piperidone ring of cYY with a CH2-imidazole or CH2-triazole moiety to enhance binding interaction with the heme of CYP121A1. The series displayed moderate to weak type II binding affinity for CYP121A1, with the exception of series B 10a, which displayed mixed type I binding. Of the three series, series C imidazole derivatives showed the best, although modest, inhibitory activity against M. tuberculosis (17d MIC = 12.5 μg/mL, 17a 50 μg/mL). Crystal structures were determined for CYP121A1 bound to series A compounds 6a and 6b that show the imidazole groups positioned directly above the haem iron with binding between the haem iron and imidazole nitrogen of both compounds at a distance of 2.2 ?. A model generated from a 1.5 ? crystal structure of CYP121A1 in complex with compound 10a showed different binding modes in agreement with the heterogeneous binding observed. Although the crystal structures of 6a and 6b would indicate binding with CYP121A1, the binding assays themselves did not allow confirmation of CYP121A1 as the target.
- El-wahab, Hend A.A. Abd,Accietto, Mauro,Marino, Leonardo B.,McLean, Kirsty J.,Levy, Colin W.,Abdel-Rahman, Hamdy M.,El-Gendy, Mahmoud A.,Munro, Andrew W.,Aboraia, Ahmed S.,Simons, Claire
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p. 161 - 176
(2017/11/29)
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- Manganese catalyzed reductive amination of aldehydes using hydrogen as a reductant
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A one-pot two-step procedure was developed for the alkylation of amines via reductive amination of aldehydes using molecular dihydrogen as a reductant in the presence of a manganese pyridinyl-phosphine complex as a pre-catalyst. After the initial condensation step, the reduction of imines formed in situ is performed under mild conditions (50-100 °C) with 2 mol% of catalyst and 5 mol% of tBuOK under 50 bar of hydrogen. Excellent yields (>90%) were obtained for a large combination of aldehydes and amines (40 examples), including aliphatic aldehydes and amino-alcohols.
- Wei, Duo,Bruneau-Voisine, Antoine,Valyaev, Dmitry A.,Lugan, No?l,Sortais, Jean-Baptiste
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supporting information
p. 4302 - 4305
(2018/05/03)
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- One-pot synthesis of imidazolinium salts via the ring opening of tetrahydrofuran
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A new one-pot synthesis of C2-hydroxypropyl-substituted imidazolinium salts via the ring opening of tetrahydrofuran (THF) with N,N′-disubstituted diamines has been developed. Preliminary studies of the reaction mechanism suggest the CO2-promoted oxidative ring opening of THF followed by Hg(ii)-mediated oxidation of an imidazolidine intermediate. These novel C2-substituted imidazolinium salts have shown to be active catalysts for the aza-Diels-Alder reactions.
- Huang, Yong-Qing,Zhao, Yue,Wang, Peng,Okamura, Taka-Aki,Laforteza, Brian N.,Lu, Yi,Sun, Wei-Yin,Yu, Jin-Quan
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supporting information
p. 12430 - 12433
(2017/10/06)
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- Photoinduced Copper(I)-Catalyzed Cyanation of Aromatic Halides at Room Temperature
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The first photoinduced copper(I)-catalyzed cyanation of aromatic halides at room temperature has been developed. The sp2 cyanation reaction exhibits outstanding tolerance to functional groups including primary amines and carboxylic acids, and chemoselectivity to SN2-reactive alkyl chlorides. Mechanistic investigations indicate that the reaction occurs via a single-electron transfer (SET) between the aryl halide and an excited copper(I) cyanide catalytic intermediate. (Figure presented.).
- Kim, Kicheol,Hong, Soon Hyeok
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supporting information
p. 2345 - 2351
(2017/07/22)
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- Efficient route to pre-organized and linear polyaminopolycarboxylates: Cy-TTHA, Cy-DTPA and mono/di- reactive, tert-butyl protected TTHA/Cy-TTHA
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Pre-organized polyaminopolycarboxylate chelators Cy-TTHA and Cy-DTPA were synthesized via modular five-step syntheses from commercially available starting materials in ～62% and 47% overall yields, respectively. Furthermore, strategies are reported for the efficient preparation of mono- and di-reactive, tert-butyl-protected TTHA/Cy-TTHA to selectively functionalize central chelators’ carboxylic acids.
- Mohamadi, Ali,Miller, Lawrence W.
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supporting information
p. 1441 - 1444
(2017/03/23)
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- Photophysical properties of di-Schiff bases: Evaluating the synergistic effect of non-covalent interactions and alkyl spacers in enhanced emissions of solids
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Photophysical properties of di-Schiff base compounds in the solution and solid states are explored. The di-Schiff bases with alkyl spacers (ethyl, butyl and hexyl) showed enhanced light emitting properties in the solid state, while quenching was observed for di-Schiff bases with a hydrazine spacer. The photoluminescence spectra and the crystal structure were compared with bis-pyridyl-ethyl-di-imine and bis-pyridyl-butyl-di-imine. The crystal structure analysis of the compounds rationalizes the observed results. The concentration dependent 1H-NMR and NOESY spectra showed the aggregation behaviour of the compounds.
- Das, Moyna,Baig, Fayaz,Sarkar, Madhushree
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p. 57780 - 57792
(2016/07/06)
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- Functionalized Salen ligands linking with non-conjugated bridges: unique and colorful aggregation-induced emission, mechanism, and applications
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A series of novel, simple, and colorful Salen ligands (56 samples), salicylaldehyde-based bis-Schiff bases, linking with different non-conjugated alkyl bridges ((CH2)n, n = 2-9, 12; cyclohexyl) and containing different electron-accepting (-NO2, -F, and -Cl), electron-donating (-OMe, -OH, and -NEt2), or sterically hindering (-t-butyl) substituents or a π-extended system (naphthalene ring) have been designed and synthesized. The photophysical properties of these Salen ligands can be well-tuned by the introduction of side functional substituents, π-extended systems, and central N-alkyl chain bridges. It is unusual that they contain a small π-conjugated system but display strong blue, green, and red aggregation-induced emission (AIE) with large Stokes shifts (up to 162 nm) and high fluorescence quantum yields (up to 0.44 and 0.75 in water and in solid, respectively). Combining with their advantages of AIE and good stability and biocompatibility, the Salen ligands can be potentially used in mechanofluorochromism (crystal-defect-induced emission) and living cell imaging. Moreover, the inherent relationships between their chemical structures and AIE properties are studied, which provide unequivocal insights for the design of AIE-active dyes.
- Cheng, Jinghui,Li, Yuanxi,Sun, Rui,Liu, Jiaoyan,Gou, Fei,Zhou, Xiangge,Xiang, Haifeng,Liu, Jin
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supporting information
p. 11099 - 11110
(2015/11/09)
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- Structure-property relationships of aromatic polyamides and polythioamides: comparative consideration with those of analogous polyesters, polythioesters and polydithioesters
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Conformational characteristics and configurational properties of aromatic polyamides and polythioamides, analogues of common aromatic polyesters such as poly(ethylene terephthalate) and poly(trimethylene terephthalate), have been investigated via NMR experiments and molecular orbital calculations on model compounds, and the refined rotational isomeric state calculations for the polymers. The polyamides and polythioamides were actually synthesized and characterized in terms of solubility, molecular weight, crystallinity, thermal transition, and thermal stability. Herein, the experimental results are discussed mainly from the viewpoint of the conformational characteristics and compared with those obtained from analogous aromatic polyesters, polythioesters, and polydithioesters to reveal the effects of the heteroatoms O, S, and NH included in the backbone on the polymer structures and properties.
- Nagasawa, Masayuki,Ishii, Tatsuya,Abe, Daisuke,Sasanuma, Yuji
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p. 96611 - 96622
(2015/11/24)
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- Synthesis, ir and nmr spectral correlations in some symmetrical diimines
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A series of diimines have been synthesized by coupling of diamine with substituted benzaldehydes. The purities of these diimines were checked by their analytical and spectroscopic data. The spectral frequencies vCN (cm-1), NMR chemical shifts (v, ppm) of C-H and C=N of these diimines have been correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral data has been studied.
- Thirunarayanan
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- Synthesis and tripanocidal activity of ferrocenyl and benzyl diamines against Trypanosoma brucei and Trypanosoma cruzi
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Trypanosoma brucei and Trypanosoma cruzi are the etiologic agents of sleeping sickness and Chagas disease, respectively, two of the 17 preventable tropical infectious diseases (NTD) which have been neglected by governments and organizations working in the health sector, as well as pharmaceutical industries. High toxicity and resistance are problems of the conventional drugs employed against trypanosomiasis, hence the need for the development of new drugs with trypanocidal activity. In this work we have evaluated the trypanocidal activity of a series of N1,N2-dibenzylethane-1,2-diamine hydrochlorides (benzyl diamines) and N1-benzyl,N2-methyferrocenylethane-1,2- diamine hydrochlorides (ferrocenyl diamines) against T. brucei and T. cruzi parasite strains. We show that incorporation of the ferrocenyl group into the benzyl diamines increases the trypanocidal activity. The molecules exhibit potential trypanocidal activity in vitro against all parasite strains. Cytotoxicity assay was also carried out to evaluate the toxicity in HepG2 cells.
- Velásquez, Angela Maria Arenas,Francisco, Acácio Ivo,Kohatsu, Andréa Akiko Nakaima,Silva, Flavia Alves De Jesus,Rodrigues, Danilo Fernando,Teixeira, Rafaela Gomes Da Silva,Chiari, Bruna Galdorfini,De Almeida, Maria Gabriela José,Isaac, Vera Lucia Borges,Vargas, Maria D.,Cicarelli, Regina Maria Barretto
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p. 1707 - 1710
(2014/04/17)
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- N-heterocyclic carbene-catalyzed α-alkylation of ketones with primary alcohols
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Several N-heterocyclic carbene precursors are synthesized and used in the α-alkylations of ketones with primary alcohols. With the assistance of a base, these N-heterocyclic carbenes can catalyze the reaction smoothly to furnish dialkylated ketones in good-to-excellent yields.
- Zhu, Yanfang,Cai, Chun,Lu, Guoping
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p. 1666 - 1671
(2015/01/09)
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- Preparation of imines by oxidative coupling of benzyl alcohols with amines catalysed by dicopper complexes
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Complexation of 2,7-bis(2-pyridyl)-1,8-naphthyridine (bpnp) with Cu 2O in formic acid under aerobic conditions provided a dicopper complex [Cu2(bpnp)(μ-OH)(HCOO)3] (1). This complex has been characterized by X-ray crystallographic and spectroscopic analysis. With O2 as the oxidant, complex 1 is an efficient catalyst for the oxidative coupling of alcohols with amines or diamines, leading to the corresponding imines or diimines in good to excellent yields. A dicopper complex has been found to be an efficient catalyst for the oxidative coupling of benzyl alcohols with amines or diamines, leading to the corresponding imines or diimines in good to excellent yields without using any organic solvent. Copyright
- Lan, Yung-Syuan,Liao, Bei-Sih,Liu, Yi-Hong,Peng, Shie-Ming,Liu, Shiuh-Tzung
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supporting information
p. 5160 - 5164
(2013/11/06)
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- Synthesis and evaluation of hexahydropyrimidines and diamines as novel hepatitis C virus inhibitors
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In order to identify novel anti-hepatitis C virus (HCV) agents we devised cell-based strategies and screened phenotypically small molecule chemical libraries with infectious HCV particles, and identified a hit compound (1) containing a hexahydropyrimidine (HHP) core. During our cell-based SAR study, we observed a conversion of HHP 1 into a linear diamine (6), which is the active component in inhibiting HCV and exhibited comparable antiviral activity to the cyclic HHP 1. In addition, we engaged into the biological characterization of HHP and demonstrated that HHP does not interfere with HCV RNA replication, but with entry and release of viral particles. Here we report the results of the preliminary SAR and mechanism of action studies with HHP.
- Hwang, Jong Yeon,Kim, Hee-Young,Jo, Suyeon,Park, Eunjung,Choi, Jihyun,Kong, Sunju,Park, Dong-Sik,Heo, Ja Myung,Lee, Jong Seok,Ko, Yoonae,Choi, Inhee,Cechetto, Jonathan,Kim, Jaeseung,Lee, Jinhwa,No, Zaesung,Windisch, Marc Peter
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p. 315 - 325
(2013/11/19)
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- Zn2+-K10-clay (clayzic) as an efficient water-tolerant, solid acid catalyst for the synthesis of benzimidazoles and quinoxalines at room temperature
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A very simple, green and efficient protocol is developed in which zinc chloride-exchanged K10-montmorillonite (clayzic) is employed as a Lewis acid catalyst in aqueous media at room temperature for the synthesis of various benzimidazoles and quinoxalines from carbonyl compounds and o-phenylenediamine. Among the various catalysts (including claycop and Zn2+-Y) studied, clayzic produces benzimidazoles and quinoxalines in higher yield, and with a flexible diamine such as ethylenediamine only the bis-Schiff base is formed. Other salient features of this protocol include milder conditions, atom-economy, absence of coupling agents, and no wastes.
- Dhakshinamoorthy, Amarajothi,Kanagaraj, Kuppusamy,Pitchumani, Kasi
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supporting information; scheme or table
p. 69 - 73
(2011/02/25)
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- Design, synthesis and biological activity of peptidomimetic analogs of insect allatostatins
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Allatostatins (ASTs) comprise a family of insect neuropeptides isolated from cockroaches and found to inhibit the production of juvenile hormone (JH) by the corpora allata (CA). For this reason, the ASTs can be regarded as possible IGR candidates for pest control. Six peptidomimetic analogs according to the C-terminal pentapeptide of ASTs were prepared by solid-phase organic synthetic methods in an attempt to obtain new simple substitution agents. Assays of inhibition of JH biosynthesis in vitro by corpora allata from the cockroach Diploptera punctata showed that the activity of analog I (IC50: 0.09 μM) was more active than that of the C-terminal pentapeptide (Tyr-Xaa-Phe-Gly-Leu-NH2, IC50: 0.13 μM) it mimicked and the activity of the analog II (IC50: 0.13 μM) proved roughly equivalent to the C-terminal pentapeptide. The results indicate that a new simple mimicry for Tyr-Xaa-Phe-Gly has been discovered; analog I may be a novel compound candidate for potential IGRs. This study will be useful for the design of new AST analogs for insect management.
- Xie, Yong,Kai, Zhen Peng,Tobe, Stephen S.,Deng, Xi Le,Ling, Yun,Wu, Xiao Qin,Huang, Juan,Zhang, Li,Yang, Xin Ling
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experimental part
p. 581 - 586
(2012/01/13)
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- Copper-catalyzed amidation of aryl iodides in the presence of various chelating ligands
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N,N′-Dibenzylethylenediamine is presented as a new, efficient, and versatile bidentate ligand suitable for the copper catalyzed formation of the C-N bond. This bidentate ligand has been demonstrated to facilitate the copper catalyzed cross-coupling reactions of aryl iodides with amides to afford the desired products in good to excellent yields.
- Hosseinzadeh, Rahman,Golchoubian, Hamid,Masoudi, Mahtab
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body text
p. 649 - 653
(2009/05/11)
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- Synthesis of [N, N'-Bis(5-benzoyl-4-phenylthiazol-2-yl)-N, N-bisbenzyl]ethane-1, 2-diamines
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Synthesis of [N,N'-bis(N-benzoylthiocarbamoyl)-N,N'-bis(benzyl)]ethane-1,2- diamines 4a-h, their cyclization to [N,N'-bis(5-benzoyl-4-phenylthiazol-2-yl)-N, N'-bisbenzyl]ethane-1,2-diamines 5a-h by reaction with phenacyl bromide and the results of antibacterial activity assay of 4a-h and 5a-h are reported.
- Asha,Manju,Pradeep,George,Rajasekharan
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scheme or table
p. 1726 - 1730
(2009/05/30)
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- Microwave-assisted efficient synthesis of diimines in dry media using silica gel supported sodium hydrogen sulfate as reusable solid support
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A simple and efficient method for synthesis of diimines using silica gel supported sodium hydrogen sulfate as reusable solid support in solvent-free conditions under microwave irradiation is described.
- Bazgir, Ayoob
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- Discovery of chiral catalysts by asymmetric activation for highly enantioselective diethylzinc addition to imines: Using racemic and achiral diimines as effective activators
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A library of chiral zinc complexes formed in situ by the combination of achiral and racemic diimines with 3,3′-di(3,5-ditrifluoromethylphenyl)- BINOL and diethylzinc were evaluated in the asymmetric addition of diethylzinc to N-acylimines. In the presence of 10 mol % of chiral ligand 4 and racemic diimine 5, high enantioselectivities of up to 97% ee and yields of up to 96% were achieved for a wide range of aromatic imines in dichloromethane at -30°C.
- Liu, Hua,Zhang, Hai-Le,Wang, Shuang-Jun,Mi, Ai-Qiao,Jiang, Yao-Zhong,Gong, Liu-Zhu
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p. 2901 - 2907
(2007/10/03)
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- Synthesis, crystal structures, and third-order nonlinear optical properties of two novel complexes of H4edbbp with Zn(II), Cd(II)
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We synthesized a new organo-diphosphonic acid ligand H2O 3PCH(Ph)NH(CH2)2NH(Ph)CHPO3H 2 [ethane-1,2-diamino-N,N′-bis(benzyl phosphonic)acid, H 4edbbp] and its two complexes [NH3CH(CH 3)CH2NH3]2M2(edbbp) 2·H2O [M=Zn(II) (1), Cd(II) (2)] in this paper. The complexes 1-2 were structurally characterized by means of X-ray single crystal diffraction. The central ion (M=Zn or Cd) has a distorted square-pyramidal coordination environment by three oxygen atoms from phosphonate units and two nitrogen atoms of H4edbbp. The fundamental structural units [M 2(edbbp)2]4- are linked by extensive intermolecular hydrogen bonds between 1,2-propyldiamine cations and phosphonate oxygen atoms, forming a one-dimensional chain structure. The third-order nonlinear optical (NLO) properties of 2 were determined by Z-scan techniques. NLO refractive index n2, χ(3) of 2's, and hyperpolarizability γ values were calculated to be 1.31×10 -17 m2 W-1, 3.19×10-11 and 8.57×10-30 esu, respectively. The results indicate that complex 2 exhibits very strong NLO absorption and self-focusing effects.
- Fan, Yao-Ting,Xue, Dong-Xu,Li, Gang,Hou, Hong-Wei,Du, Chen-Xia,Lu, Hui-Jie
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p. 153 - 160
(2007/10/03)
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- A convenient "one-pot" reaction for selective monoalkylation of N,N′-disubstituted ethylenediamines
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A study on the scope of the method to obtain N,N,N′-trisubstituted ethylenediamines III by monoalkylation of N,N′-disubstituted ethylenediamines I through a "one-pot" reaction is presented. It involves condensation of compounds I with aldehydes followed by reduction of the formed imidazolidines II without previous isolation.
- Salerno, Alejandra,Figueroa, Maria Amalia,Perillo, Isabel A.
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p. 3193 - 3204
(2007/10/03)
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- Synthesis of imines, diimines and macrocyclic diimines as possible ligands, in aqueous solution
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Although it is recognized that the presence of water is disadvantageous for imine synthesis, we demonstrate that such synthesis can be effective in completely aqueous media, without any catalyst and under mild conditions. Thus, arylaryl, aryl-alkyl, alkyl-aryl and alkyl-alkyl monoimines as well as a large variety of diimines are obtained by direct condensation of the corresponding carbonyl compounds and amines, in water. The same process is used to synthesize macrocyclic diimines starting from methylene, ethylene, trimethylene and tetramethylene glycol bis(2-formylphenyl ether) and ethylene-, trimethylene- and tetramethylene-diamine, some of these macrocycles being known for their chelating properties.
- Simion, Alina,Simion, Cristian,Kanda, Tadeshige,Nagashima, Satoko,Mitoma, Yoshiharu,Yamada, Tomoko,Mimura, Keisuke,Tashiro, Masashi
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p. 2071 - 2078
(2007/10/03)
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- Synthesis of novel tetrahydroimidazole derivatives and studies for their biological properties
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Ethylenediamine was reacted with suitable aromatic aldehydes in order to prepare their respective diSchiff bases. These compounds were then reduced to give the corresponding tetrahydrodiSchiff bases, which were low melting in nature. Finally, these derivatives were condensed with different aromatic aldehydes to give the desired tetrahydroimidazoles. The structures of all these compounds were established on the basis of spectral data. These novel tetrahydroimidazoles showed promising anti-inflammatory and analgesic activity. The compounds were also screened for their anti-bacterial property against Staphylococcus aureus and Escherichia coli.
- Sharma, Vibha,Khan
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p. 651 - 658
(2007/10/03)
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- New photoluminescent Cu1N4 chromophores. Stabilisation of copper(1) by unconjugated diimines
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Two new photoluminescent homoleptic distorted tetrahedral Cu1N4 chromophores with CuII/I potentials of 0.66-0.81 V vs. SCE are isolated by using two unconjugated diimines (2:1 condensates of R1R2C=O and ethylenediamine; R1 = Ph, R2 = H; R1 = R2 = Ph) as ligands. The Royal Society of Chemistry 2000.
- Chowdhury, Shubhamoy,Patra, Goutam K.,Drew, Michael G.B.,Chattopadhyay, Nitin,Datta, Dipankar
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p. 235 - 237
(2007/10/03)
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- O2 activation and aromatic hydroxylation performed by diiron complexes
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Chemical models of active sites of diiron oxo proteins have been synthesized. The polydendate ligands are EDTA derivatives which provide a balanced supply of nitrogen atoms and carboxylate groups together with an oxidizable phenyl moiety, thus mimicking both the iron coordination in methane monooxygenase and a nearby substrate site. All the diferric complexes have been characterized in solution by ESI-MS, optical absorption, and in some cases by 1H NMR. In the case of the ligand L1 [L1 = (N,N'-bis(3,4,5- trimethoxybenzyl)ethylenediamine N,N'-diacetic acid)], the X-ray structure of the corresponding iron complex has been determined, revealing an original tetranuclear unit, Fe4O2(L1)4·10H2O, issued from the dimerization of two [Fe2O(L1)2] units linked by carboxylate bridges. In a solution containing water or acetate, the tetranuclear complex decomposed into dinuclear complexes, which proved to be able to react with hydrogen peroxide or dioxygen in the presence of ascorbate. The final product was a mononuclear complex identified as [Fe(III)L'1(H2O)] with L'1 resulting from the quantitative hydroxylation of L1. The complex and the oxidized ligand were characterized by EPR, NMR, and UV-vis spectroscopies and by mass spectrometry. Labeling experiments showed that with both H2O2 or O2 and ascorbate, the incorporated oxygen came from the oxidant exclusively. This reaction mimicks the transformation of a tyrosine residue, brought into proximity of the active center of Ribonucleotide reductase of Escherichia coli by site-directed mutagenesis, into 3,4-dihydroxyphenylalanine.
- Ménage, Stéphane,Galey, Jean-Baptiste,Dumats, Jacqueline,Hussler, Georges,Seité, Michel,Luneau, Isabelle Gautier,Chottard, Geneviève,Fontecave, Marc
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p. 13370 - 13382
(2007/10/03)
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- Synthesis of a new type of N2S2 tetradentate ligand
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Synthesis of a new type of N2S2 tetradentate ligand 3 possessing the bis-(hydrazonothioamide) structure based on condensation of the dihydrazines 8 with an α-ketoester is described.
- Charrier, Jean-Damien,Reliquet, Alain,Meslin, Jean-Claude
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p. 8645 - 8646
(2007/10/03)
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- Homochiral lithium amides: Enantioselective deprotonation of cyclohexene oxide
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Reaction of cyclohexene oxide with chiral lithium amides has been studied and (S)-2-cyclohexen-1-ol was prepared in 20-82% ee. The optical purity was determined by proton NMR measurement of α-methoxy-α- (trifluoromethyl)phenylacetic acid (MTPA) derivative of the corresponding alcohol.
- Bhuniya,Singh
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p. 375 - 385
(2007/10/02)
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- Studies on the Oxidation of the Azomethine Compounds with 3-Chloroperbenzoic Acid
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Oxidation of the azomethine compounds such as Schiff bases and azines having several nucleophilic centers with 3-chloroperbenzoic acid (MCPBA) being an electrophilic oxidant was investigated.From azines 4, bisaldimines 5, 6, and pyridine derived monoaldimines 7, 8, having various substituents on the imine carbon and nitrogen atoms, the products such as nitrones 9, 15, bisoxaziridines 11, 12; acyldiimine 10 and amide 14 were obtained in high yields.The influence of the structure of substrate on the reaction result is discussed.Key words: aldimines, azines, nitrones, oxaziridines
- Mlochowski, J.,Abdel-Latif, F. F.,Kubicz, E.,Said, S. B.
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p. 711 - 722
(2007/10/02)
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- NOVEL SYNTHESES OF HETEROCYCLES WITH N-(1-HALOALKYL)AZINIUM HALIDES PART 1. PREPARATION OF IMIDAZOLIDINES
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N-(1-Chloroalkyl)pyridinium chlorides, prepared from thionyl chloride, pyridine, and an aldehyde, readily react with N,N'-disubstituted 1,2-ethanediamine to yield imidazolidines under mild and neutral conditions.
- Eynde, J.-J. Vanden,Mayence, A.,Maquestiau, A.,Anders, E.
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p. 233 - 236
(2007/10/02)
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- Stereochemistry of N,N'-Bis--ethylenediamine
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N,N'-Bis--ethylene diamine (5), synthesized from racemic 1,2-anhydro-3-O-(o-ethoxyphenyl)-glycerol (1) and ethylene diamine (2) or N,N'-dibenzyl ethylene diamine (3) crystallized in two fractions with different melting points.Both of these analytically pure products gave identical two spot tl-chromatograms on achiral phases.Attempts were made to resolve the mixtures which proved to consist of configurative but not constitutive isomers.Optically pure products were synthesized from chiral precursors.
- Kristen, H.,Wrubel, F.,Widuwild, H.,Luecke, L.
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p. 545 - 554
(2007/10/02)
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- Dioxouranium(VI) complexes of tetradentate schiff base ligands
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Twelve neutral dioxouranium(VI) complexes of tetradentate schiff bases obtained by the condensation of pyridine-2-carboxaldehyde or 2-acetylpyridine with ethylenediamine and propylenediamine are reported.The complexes have the general formula UO2(L)X2, where L = neutral tetradentate ligand and X = Cl-, NCS-, NO3-.The complexes are characterized by analytical, electrical conductivity and infrared spectral studies.The thiocyanate ions are N-bonded and the nitrate ions are bonded in a bidentate manner.
- Singh, S,Chakravortty, V,Dash, K C
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p. 713 - 715
(2007/10/02)
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- ACCESS TO AMINOPHENYLCARBENES VIA DIAZIRINE EXCHANGE REACTIONS
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Phenylbromodiazirine (1) reacts with a variety of primary and secondary amines affording a series of aminophenylcarbenes.
- Moss, Robert A.,Cox, D. Phillip,Tomioka, Hideo
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p. 1023 - 1026
(2007/10/02)
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