619-45-4Relevant academic research and scientific papers
Photosensitive self-assembled monolayers on gold: Photochemistry of surface-confined aryl azide and cyclopentadienylmanganese tricarbonyl
Wollman, Eric W.,Kang, Doris,Frisbie, C. Daniel,Lorkovic, Ivan M.,Wrighton, Mark S.
, p. 4395 - 4404 (1994)
Photosensitive self-assembled monolayers (SAMs) are prepared by the spontaneous reaction of di-11-(4-azidobenzoate)-1-undecyl disulfide, I, or 11-mercaptoundecylcyclopentadienylmanganese tricarbonyl, II, with polycrystalline Au. SAMs of I are photosensitive by virtue of a pendant aryl azide moiety (λmax = 270 nm, log ε = 4.2) which undergoes photoreaction with secondary amines to form Au-confined derivatives of 3-H azepine and hydrazine, while Au-II SAMs undergo photosubstitution of phosphine for CO. Au-I SAMs irradiated in the presence of various secondary amines were characterized by reflection absorption infrared spectroscopy (RAIRS), XPS, and cyclic voltammetry, and showed persistent attachment of approximately one monolayer of amine. Infrared spectroscopy was used to establish that primary photoproducts obtained upon irradiation of Au-I SAMs in diethylamine are nearly identical to primary photoproducts obtained upon irradiating an analog of I, methyl 4-azidobenzoate, in diethylamine solution. XPS analysis of Au-I SAMs before and after irradiation in the presence of secondary amines confirms loss of N2 from the Au-I SAM and incorporation of one nitrogen atom per surface-confined molecule. Most definitively, cyclic voltammetry of Au-I after irradiation in the presence of 2-ferrocenylethyl-2′,2′,2′-trifluoroethylamine, III, showed 3.3 × 10-10 mol cm-2 of surface-confined ferrocene. Positive ion SIMS spectra of Au-II irradiated in the presence of PPh2Et, PPh2(n-Pr), PPh2(CH2)11Fc, X, Fc = ferrocenyl, or PPh2(CH2)2(CF2)5CF 3, XI, show that introduction of the phosphine onto the surface occurs upon near-UV irradiation. Importantly, the surface photochemistry of I and II allows the high lateral resolution patterning of Au surfaces and Au microstructures with a variety of molecular reagents. SIMS maps for vinyl ferrocenium (m/z 212) or F- (m/z 19) of flat Au-II substrates irradiated through a Cr-on-glass mask in the presence of X or XI demonstrate photochemical patterning at a lateral resolution of 2H5OH)2NH.
Hypersensitive azobenzenes: Facile synthesis of clickable and cleavable azo linkers with tunable and high reducibility
Eom, Taejun,Khan, Anzar
, p. 420 - 424 (2020)
The aim of this work is to show that by increasing the number of donor substituents in a donor/acceptor system, the sensitivity of the azobenzene linkage towards a reductive cleavage reaction can be enhanced to unprecedented high levels. For instance, in a triple-donor system, less than a second constitutes the half-life of the azo (NN) bond. Synthetic access to such redox active scaffolds is highly practical and requires only 1-2 synthetic steps. The fundamental molecular design is also adaptable. This is demonstrated through scaffold functionalization by azide, tetraethylene glycol, and biotin groups. The availability of the azide group is shown in a copper-free 'click' reaction suitable in context with protein conjugation and proteomics application. Finally, the clean nature of the scission process is demonstrated with the help of liquid chromatography coupled with mass analysis. This work, therefore, describes development of cleavable azobenzene linkers that can be accessed with synthetic ease, can be multiply functionalized, and show a clean and rapid response to mild reducing conditions.
A new monoclinic polymorph of methyl p-aminobenzoate
Doriguetto, Antonio C.,De Paula Silva, Carlos H.T.,Rando, Daniela G.,Ferreira, Elizabeth I.,Ellena, Javier
, p. o69-o71 (2004)
The crystal structure of methyl-p-aminobenzoate (MAB) was analyzed. A P21/c polymorph of MAB was found and the intra and intermolecular geometries were compared with those of the previously known C2/c structure. It was found that in the C2/c polymorph, two hydrogen bonds formed infinite chains along the [110] and [110] directions. The molecule was also found to be almost flat, and the largest deviations from the least square plane through the aromatic rings were 0.300 (3) and 0.180 (2) A for the atoms C8 and O2 respectively.
Carboxyl Methyltransferase Catalysed Formation of Mono- and Dimethyl Esters under Aqueous Conditions: Application in Cascade Biocatalysis
Ashbrook, Chloe,Carnell, Andrew J.,Goulding, Ellie,Hatton, Harry,Johnson, James R.,Kershaw, Neil M.,McCue, Hannah V.,Rigden, Daniel J.,Ward, Lucy C.
supporting information, (2022/02/21)
Carboxyl methyltransferase (CMT) enzymes catalyse the biomethylation of carboxylic acids under aqueous conditions and have potential for use in synthetic enzyme cascades. Herein we report that the enzyme FtpM from Aspergillus fumigatus can methylate a broad range of aromatic mono- and dicarboxylic acids in good to excellent conversions. The enzyme shows high regioselectivity on its natural substrate fumaryl-l-tyrosine, trans, trans-muconic acid and a number of the dicarboxylic acids tested. Dicarboxylic acids are generally better substrates than monocarboxylic acids, although some substituents are able to compensate for the absence of a second acid group. For dicarboxylic acids, the second methylation shows strong pH dependency with an optimum at pH 5.5–6. Potential for application in industrial biotechnology was demonstrated in a cascade for the production of a bioplastics precursor (FDME) from bioderived 5-hydroxymethylfurfural (HMF).
A “universal” catalyst for aerobic oxidations to synthesize (hetero)aromatic aldehydes, ketones, esters, acids, nitriles, and amides
Bartling, Stephan,Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Rabeah, Jabor,Rockstroh, Nils,Senthamarai, Thirusangumurugan
supporting information, p. 508 - 531 (2022/02/11)
Functionalized (hetero)aromatic compounds are indispensable chemicals widely used in basic and applied sciences. Among these, especially aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides represent valuable fine and bulk chemicals, which are used in chemical, pharmaceutical, agrochemical, and material industries. For their synthesis, catalytic aerobic oxidation of alcohols constitutes a green, sustainable, and cost-effective process, which should ideally make use of active and selective 3D metals. Here, we report the preparation of graphitic layers encapsulated in Co-nanoparticles by pyrolysis of cobalt-piperazine-tartaric acid complex on carbon as a most general oxidation catalyst. This unique material allows for the synthesis of simple, functionalized, and structurally diverse (hetero)aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides from alcohols in excellent yields in the presence of air.
Selective Reduction of Nitroarenes to Arylamines by the Cooperative Action of Methylhydrazine and a Tris(N-heterocyclic thioamidate) Cobalt(III) Complex
Ioannou, Dimitris I.,Gioftsidou, Dimitra K.,Tsina, Vasiliki E.,Kallitsakis, Michael G.,Hatzidimitriou, Antonios G.,Terzidis, Michael A.,Angaridis, Panagiotis A.,Lykakis, Ioannis N.
supporting information, p. 2895 - 2906 (2021/02/27)
We report an efficient catalytic protocol that chemoselectively reduces nitroarenes to arylamines, by using methylhydrazine as a reducing agent in combination with the easily synthesized and robust catalyst tris(N-heterocyclic thioamidate) Co(III) complex [Co(κS,N-tfmp2S)3], tfmp2S = 4-(trifluoromethyl)-pyrimidine-2-thiolate. A series of arylamines and heterocyclic amines were formed in excellent yields and chemoselectivity. High conversion yields of nitroarenes into the corresponding amines were observed by using polar protic solvents, such as MeOH and iPrOH. Among several hydrogen donors that were examined, methylhydrazine demonstrated the best performance. Preliminary mechanistic investigations, supported by UV-vis and NMR spectroscopy, cyclic voltammetry, and high-resolution mass spectrometry, suggest a cooperative action of methylhydrazine and [Co(κS,N-tfmp2S)3] via a coordination activation pathway that leads to the formation of a reduced cobalt species, responsible for the catalytic transformation. In general, the corresponding N-arylhydroxylamines were identified as the sole intermediates. Nevertheless, the corresponding nitrosoarenes can also be formed as intermediates, which, however, are rapidly transformed into the desired arylamines in the presence of methylhydrazine through a noncatalytic path. On the basis of the observed high chemoselectivity and yields, and the fast and clean reaction processes, the present catalytic system [Co(κS,N-tfmp2S)3]/MeNHNH2 shows promise for the efficient synthesis of aromatic amines that could find various industrial applications.
METHOD OF PREPARING(3R,5R)-7-(2-(4-FLUOROPHENYL)-5-ISOPROPYL-3-PHENYL-4-((4-HYDROXYMETHYLPHENYLAMINO)CARBONYL)-PYRROL-1-YL)-3,5-DIHYDROXY-HEPTANOIC ACID HEMI CALCIUM SALT, AND METHOD OF PREPARING INTERMEDIATES USED THEREIN
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Paragraph 0079-0082, (2021/02/05)
The present invention provides a method for preparing (3R,5R)-7-(2-(4-flurophenyl)-5-isopropyl-3-phenyl-4-((4-hydroxymethylphenylamino)carbonyl)-pyrrole-1-yl)-3,5-dihydroxy heptanoic acid hemicalcium salt. The preparation method of the present invention is performed in a convergent synthesis manner in which main structural moieties of a (3R,5R)-7-(2-(4-flurophenyl)-5-isopropyl-3-phenyl-4-((4-hydroxymethylphenylamino)carbonyl)-pyrrole-1-yl)-3,5-dihydroxy heptanoic acid hemicalcium salt are independently synthesized, and then coupled. Accordingly, related substances can be easily controlled and preparing time can be reduced, thus improving the productivity of a compound, and the yield of a final compound can also be increased.
Optimizing the structure of (salicylideneamino)benzoic acids: Towards selective antifungal and anti-staphylococcal agents
Krátky, Martin,Kone?ná, Klára,Broke?ová, Kate?ina,Maixnerová, Jana,Trejtnar, Franti?ek,Vin?ová, Jarmila
, (2021/02/03)
An increasing resistance of human pathogenic bacteria and fungi has become a global health problem. Based on previous reports of 4-(salicylideneamino)benzoic acids, we designed, synthesised and evaluated their me-too analogues as potential antimicrobial agents. Forty imines derived from substituted salicylaldehydes and aminobenzoic acids, 4-aminobenzoic acid esters and 4-amino-N-phenylbenzamide were designed using molecular hybridization and prodrug strategies. The target compounds were synthesized with high yields and characterized by spectral methods. They were investigated against a panel of Gram-positive and Gram-negative bacteria, mycobacteria, yeasts and moulds. The most active imines were tested to determine their cytotoxicity and selectivity in HepG2 cells. Dihalogenosalicylaldehydes-based derivatives showed potent broad-spectrum antimicrobial properties, particularly against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (minimum inhibitory concentrations, MIC, from 7.81 μM) and Enterococcus faecalis (MIC of ≥15.62 μM), yeasts (MIC from 7.81 μM) and Trichophyton interdigitale mould (MIC of ≥3.90 μM). Methyl 4-[(2-hydroxy-3,5-diiodobenzylidene)amino]benzoate 4h exhibited excellent in vitro activity along with low toxicity to mammalian cells. This compound is selective for staphylococci, Candida spp. and Trichophyton interdigitale. In addition, this imine was evaluated as a potential inhibitor of Gram-positive biofilms. The successful approach used provided some promising derivatives with more advantageous properties than the parent 4-(salicylideneamino)benzoic acids.
An amino-functionalized three-dimensional cadmium metal–organic framework: Synthesis, characterization and excellent fluorescence sensing of Fe3+
Han, Youjie,Tian, Ye,Yin, Jifa,Zhu, Hongmei
, p. 845 - 849 (2021/06/06)
An amino-functionalized three-dimensional cadmium metal–organic framework, [Cd1.5(L)(DMF)]·2H2O (complex 1) L = H3TTCA-NH2 = 2′-amino-[1,1′:3′,1″-terphenyl]-4,4″,5′-tricarboxylic acid), is successfully synthesized under solvothermal conditions and structurally characterized. Interestingly, as a transition metal organic framework, the cadmium metal–organic framework exhibits favorable luminescence properties. In addition, the cadmium metal–organic framework reveals excellent selective and sensitive fluorescence sensing for the recognition of Fe3+ with high quenching efficiency (Ksv = 3.340 × 103 M?1), demonstrating that the cadmium metal–organic framework can be used as a potential sensor for Fe3+.
Biobased Spiroimides from Itaconic Acid and Formamides: Molecular Targets for a Novel Synthetic Application of Renewable Chemicals
Hornink, Milene Macedo,Lopes, Alice Uva,Andrade, Leandro Helgueira
supporting information, p. 296 - 308 (2020/11/09)
Spiroimides exhibit a wide range of biological activities, such as anticonvulsant, antiarrhythmic, and antihyperglycemic activities. Herein, a novel synthetic application of renewable chemicals, itaconic acid and formamides, is described. Proper exploitation of the reactivity of itaconic acid and formamide allows for the development of an efficient synthetic approach for the production of several new biobased spiroimides, spiro[dihydroquinolin-2-one-succinimides] and spiro[indolin-2-one-glutarimides], in excellent overall yields (up to 98%).
