Quadrol-Pd(II) complexes: phosphine-free precatalysts for the room-temperature Suzuki-Miyaura synthesis of nucleoside analogues in aqueous media

2022 ◽  
Author(s):  
Jose Luis Serrano ◽  
Sujeet Gaware ◽  
Jose Antonio Pérez de Haro ◽  
Jose Pérez ◽  
Pedro Lozano ◽  
...  

Commercially available Quadrol, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine (THPEN), has been used for the first time as N^N- donor neutral hydrophilic ligand in the synthesis and characterization of new water soluble palladium (II) complexes...

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Monir Tabatabai ◽  
Helmut Ritter ◽  
Monika Schmelzer

AbstractThe synthesis and characterization of N-methacryloyl-L-tyrosine methyl ester (3a) and ethyl ester (3b), and their acetyl derivatives O-acetyl-N-methacryloyl- L-tyrosine methyl ester (4a) and ethyl ester (4b) are described. Monomers 3 and 4 were complexed with RAMEB (randomly methylated ß-cyclodextrin) yielding water soluble host-guest complexes 5a-d. The radical polymerization of monomers 3 and 4 was investigated in the presence as well as in the absence of RAMEB in aqueous medium at room temperature and also at 60°C. It is shown that the polymerization tendency of complexes 5a-d at room temperature is lower, leading to polymers of higher molecular weight, compared to the free monomers 3 and 4. Furthermore, the polymerization of monomers 3 and 4 was carried out in homogenous organic solution using 2,2’-azoisobutyronitrile as initiator, and the results are discussed.


2017 ◽  
Vol 5 (22) ◽  
pp. 10986-10997 ◽  
Author(s):  
Xiaofei Zhang ◽  
Lixin Chen ◽  
Jin Yun ◽  
Xiaodong Wang ◽  
Jie Kong

In this work, we present, for the first time, the synthesis and characterization of magnetic Si–C–Fe hybrid microspheres and their catalytic performance in room temperature reduction of nitroarenes as a representative sustainable process for converting environmental pollutants to fine chemicals.


2018 ◽  
Vol 22 (08) ◽  
pp. 679-685 ◽  
Author(s):  
Mahdi Hajimohammadi ◽  
Maryam Khalaji Verjani ◽  
Hoda Ghasemi ◽  
Nasser Safari ◽  
Günther Knör

A new green, environmentally friendly and economically feasible method for the oxygenation of benzaldehyde, cinnamaldehyde, 4-chlorobenzaldehyde and 4-bromobenzaldehyde to the corresponding carboxylic acids using air in the presence of hemoglobin as a water-soluble catalyst in aqueous media at room temperature is illustrated. The resulting products were obtained with (77–100%) conversion and 100% selectivity within a reasonable amount of time. In addition, the first direct characterization of a high-valent iron intermediate (HbFe[Formula: see text]O) measured using Mass Spectroscopy (MS) and UV-vis spectroscopy proved that the major route for oxidation of aldehydes is (HbFe[Formula: see text]O) production.


2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.


RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13245-13255
Author(s):  
Mehdi Davoodi ◽  
Fatemeh Davar ◽  
Mohammad R. Rezayat ◽  
Mohammad T. Jafari ◽  
Mehdi Bazarganipour ◽  
...  

New nanocomposite of zeolitic imidazolate framework-67@magnesium aluminate spinel (ZIF-67@MgAl2O4) has been fabricated by a simple method at room temperature with different weight ratios.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1018
Author(s):  
Massimo Marcioni ◽  
Jenny Alongi ◽  
Elisabetta Ranucci ◽  
Mario Malinconico ◽  
Paola Laurienzo ◽  
...  

The hitherto known polyamidoamines (PAAs) are not suitable as structural materials because they are usually water-soluble or swellable in water. This paper deals with the synthesis and characterization of semi-crystalline hydrophobic PAAs (H-PAAs) by combining different bis-sec-amines with bis-acrylamides obtained from C6–C12 bis-prim-amines. H-PAAs were initially obtained in a solution of benzyl alcohol, a solvent suitable for both monomers and polymers. Their number average molecular weights, M¯n, which were determined with 1H-NMR by evaluating the percentage of their terminal units, varied from 6000 to >10,000. The solubility, thermal properties, ignitability and water resistance of H-PAAs were determined. They were soluble in organic solvents, semi-crystalline and thermally stable. The most promising ones were also prepared using a bulk process, which has never been previously reported for PAA synthesis. In the form of films, these H-PAAs were apparently unaffected by water. The films underwent tensile and wettability tests. They showed similar Young moduli (260–263 MPa), whereas the maximum stress and the stress at break depended on the number of methylene groups of the starting bis-acrylamides. Their wettability was somewhat higher than that of common Nylons. Interestingly, none of the H-PAAs considered, either as films or powders, ignited after prolonged exposure to a methane flame.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.


2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.


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