Microwave-assisted and solvent-free peroxidative oxidation of 1-phenylethanol to acetophenone with a CuII–TEMPO catalytic system

Abstract The water-soluble copper(II) complex [Cu(H2R)(HL)]∙H2O (1) was prepared by reaction of copper(II) nitrate hydrate with (E)-2-(((1-hydroxynaphthalen-2-yl)methylene)amino) benzenesulfonic acid (H2L) and diethanolamine (H3R). It was characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. 1 shows a high catalytic activity for the solvent-free microwave (MW) assisted oxidation of 1-phenylethanol with tert-butylhydroperoxide, leading, in the presence of TEMPO, to yields up to 85% (TON = 850) in a remarkably short reaction time (15 min, with the corresponding TOF value of 3.40 × 103 h− 1) under low power (25 W) MW irradiation

A bio-based alginate aerogel as an ionic liquid support for the efficient synthesis of cyclic carbonates from co2 and epoxides

Funding Information: This work was supported by Ministerio de Ciencia y Universidades (project RTI2018-097456-B-I00) and Funda??o para a Ci?ncia e Tecnologia FCT/MCTES (project PTDC/EQU-EPQ/31926/2017), UIDB/50006/2020 of the Associate Laboratory for Green Chemistry?LAQV and UIDB/00100/2020 of Centro de Qu?mica Estrutural. This work was also supported by a Short Term Scientific Mission of the CMST COST Action CM1206. A.B. Paninho is thankful to FCT for the doctoral fellowship PD/BD/52497/2014 and pos-doctoral fellowship PTDC/EQU-EPQ/31926/2017. The authors also thanks to the project ?SunStorage-Harvesting and storage of solar energy?, with reference POCI-01-0145-FEDER-016387, funded by European Regional Development Fund (ERDF), through COMPETE 2020-Operational Program. The NMR spectrometers at FCT NOVA are part of Rede Nacional de RMN (PTNMR), supported by FCT/MCTES through ROTEIRO/0031/2013? PINFRA/22161/2016 and co-financed by FEDER through COMPETE 2020, POCI, and PORL and FCT/MCTES through PIDDAC.In this work, the ionic liquid [Aliquat][Cl] was supported into alginate and silica aerogel matrices and applied as a catalyst in the cycloaddition reaction between CO2 and a bio-based epoxide (limonene oxide). The efficiency of the alginate aerogel system is much higher than that of the silica one. The method of wet impregnation was used for the impregnation of the aerogel with [Aliquat][Cl] and a zinc complex. The procedure originated a well-defined thin solvent film on the surface of support materials. Final materials were characterised by Fourier Transform Infrared Spectroscopy, N2 Adsorption–Desorption Analysis, X-ray diffraction, atomic absorption and Field Emission Scanning Microscopy. Several catalytic tests were performed in a high-pressure apparatus at 353.2 K and 4 MPa of CO2.publishersversionpublishe

DNA and BSA binding, anticancer and antimicrobial properties of Co(II), Co(II/III), Cu(II) and Ag(I) complexes of arylhydrazones of barbituric acid

Two new cocrystalline compounds, (Hen)(H2L2)$2/3H2O (2) and (Him)(H3L3)$2H2O (8), were prepared by the reaction of 5-(2-(4-chlorophenyl)hydrazono)pyrimidine-2,4,6(1H,3H,5H)-trione (H3L2) and the sodium salt of 2-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazinyl)benzenesulfonic acid (H4L3), [Na(H3L3)(m-H2O)(H2O)2]2 (1) with protonated ethylenediamine (Hen) and imidazole (Him), respectively. By using 5-(2-(2-hydroxyphenyl)hydrazono)pyrimidine-2,4,6(1H,3H,5H)-trione (H4L1) and 1, several known CuII, CoII, CoII/III and new AgI complexes, [Cu(H2L1)(H2O)(im)]$3H2O (3), [Co(H2O)6]- [Co(H2L1)2]2$8H2O (4), [Co(H2L3)(im)3] (5), [Cu(H2L3)(im)2]$H2O (6), [Ag(H2O)(m-H3L3)]n (7) and [Co(H2O)6]- [H3L3]2$8H2O (9), were also prepared in order to study their DNA and BSA binding, anticancer and antimicrobial properties. The complexes are able to interact with DNA and BSA with high binding constant values. In particular, complex 4 strongly intercalates DNA and binds BSA. The antimicrobial activity of all compounds, determined against a panel of reference bacterial and fungal strains, indicates that only 2 and 7 possess antimicrobial activity. The same compounds 2 and 7 show a pronounced antiproliferative activity against the human tumor cell lines A375, MDA-MB 231 and HCT116

9-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one

The cyclohexene ring that constitutes a part of the tetrahydroxanthene fused-ring system of the title compound, C23H26O4, adopts a flattened half-chair conformation that approximates an envelope conformation (in which the methylene C atom bearing the two methyl substituents represents the flap) as five of the six atoms lie approximately on a plane (r.m.s. deviation = 0.020 Å). The mean plane of the cyclohexene ring with the hydroxy substituent is approximately perpendicular to the mean plane of the tetrahydroxanthene system. In the crystal, adjacent molecules are linked by O—H...Ocarbonyl hydrogen bonds into a chain running along the b axis

1D Zn(II) coordination polymer of arylhydrazone of 5,5-dimethylcyclohexane-1,3-dione as a pre-catalyst for the Henry reaction

Reaction of a new hydrazone of β-diketone, 5-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)isophthalic acid (H3L), with zinc(II) nitrate hexahydrate in a mixture of DMF and water (1:1) under hydrothermal conditions affords the 1D coordination polymer [Zn(μ3-HL)(H2O)2]n ∙ nH2O (1), where one of the carboxylic groups links two Zn(II) centers in a bridging bidentate (syn-syn-type) mode and the remaining one ligates a third metal cation in a monodentate fashion. It was characterized by IR and NMR spectroscopies, ESI-MS, elemental and single-crystal X-ray crystal structural analyses. 1 acts as an efficient pre-catalyst for the Henry reaction at 40 °C in aqueous medium, providing β-nitroalcohols with good yields (67–86%) and diastereoselectivities (syn:anti 77:23–69:31).info:eu-repo/semantics/publishedVersio