Chemoselective hydrogenation of aromatic nitro compounds in the presence of homogeneous Pd based catalysts.

The chemoselective reduction of aromatic nitro compounds to amine derivatives was easily performed with remarkable yields under ultrasonic conditions in a H2O/MeOH mixture (v/v = 1/4). In this process, commercially available BINAP.PdCl2 and NaBH4 were used as homogenous catalysts and the hydrogen source, respectively. The developed method has a high economic value and can be adapted to the industry. A variety of nitroarene derivatives were reacted by undergoing the BINAP.PdCl2 catalyzed reduction reaction. All nitroarenes were selectively hydrogenated to aromatic primary amines with quantitative yields in 15 min. The obtained primary amines were determined by 1H and 13C nuclear magnetic resonance spectroscopy.

Correction to "Composites of Palladium-Nickel Alloy Nanoparticles and Graphene Oxide for the Knoevenagel Condensation of Aldehydes with Malononitrile".

[This corrects the article DOI: 10.1021/acsomega.9b00485.].

Synthesis of benzylidenemalononitrile by Knoevenagel condensation through monodisperse carbon nanotube-based NiCu nanohybrids.

Monodisperse nickel/copper nanohybrids (NiCu@MWCNT) based on multi-walled carbon nanotubes (MWCNT) were prepared for the Knoevenagel condensation of aryl and aliphatic aldehydes. The synthesis of these nanohybrids was carried out by the ultrasonic hydroxide assisted reduction method. NiCu@MWCNT nanohybrids were characterized by analytical techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), and Raman spectroscopy. According to characterization results, NiCu@MWCNT showed that these nanohybrids form highly uniform, crystalline, monodisperse, colloidally stable NiCu@MWCNT nanohybrids were successfully synthesized. Thereafter, a model reaction was carried out to obtain benzylidenemalononitrile derivatives using NiCu@MWCNT as a catalyst, and showed high catalytic performance under mild conditions over 10-180 min.

Single-Walled Carbon Nanotube Supported PtNi Nanoparticles (PtNi@SWCNT) Catalyzed Oxidation of Benzyl Alcohols to the Benzaldehyde Derivatives in Oxygen Atmosphere.

This study reports a developed process which is a general and facile method for the oxidation of benzyl alcohol (BnOH) compounds to the benzaldehyde (BA) derivatives, under mild conditions. The oxidation of BnOH species catalyzed by PtNi@SWCNT in toluene (3 ml) at 80 °C under a continuous stream of O2. Single wall carbon nanotube supported PtNi (PtNi@SWCNT) nanoparticles were synthesized using a single-step modified reduction process. The characterization of PtNi@SWCNT nanocatalyst was performed by transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and elemental analysis by ICP-OES. A variety of BnOH compounds were oxidized by the PtNi@SWCNT catalyst and all the expected oxidation products were obtained in high efficiency in 2 hours of reaction time. TLC was used to monitoring the reaction progress, and the products were identified by 1H/13C-NMR analysis.

A Novel Hydrogenation of Nitroarene Compounds with Multi Wall Carbon Nanotube Supported Palladium/Copper Nanoparticles (PdCu@MWCNT NPs) in Aqueous Medium.

A novel nanocatalyst, multi-wall carbon nanotube supported palladium/copper (PdCu@MWCNT) nanoparticles, was synthesized for the reduction of nitroarene compounds. Characterization of the nanocatalyst was achieved by XRD, XPS, TEM, and Raman spectroscopy analysis. In this study, the hydrogenation of nitroarenes to primary amine compounds was achieved in aqueous medium at room temperature. The aniline derivatives were synthesized with high yields at mild conditions via novel PdCu@MWCNT nanocatalyst. The conversion of nitroarenes to amine derivatives was accomplished at 99% efficiency. In addition to its high activity, the PdCu@MWCNT catalyst was determined to be stable and reusable after the 3rd consecutive use for the reaction and provided 99% conversion of various compounds in the reduction reaction.

Handy and highly efficient oxidation of benzylic alcohols to the benzaldehyde derivatives using heterogeneous Pd/AlO(OH) nanoparticles in solvent-free conditions.

The selective oxidation of benzylic alcohols was performed by using commercially available aluminum oxy-hydroxide-supported palladium (Pd/AlO(OH)) nanoparticles (0.5 wt.% Pd, about 3 nm size) under mild conditions. The oxidation method comprises the oxidation of benzyl alcohols catalyzed by aluminum oxy-hydroxide-supported palladium under ultrasonic and solvent-free conditions and a continuous stream of O2. The characterization of aluminum oxy-hydroxide-supported palladium nanocatalyst was conducted by several advanced analytical techniques including scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and elemental analysis by ICP-OES. The oxidation of a variety of benzyl alcohol compounds were tested by the aluminum oxy-hydroxide-supported palladium nanoparticles, and all expected oxidation products were obtained by the high conversion yields within 3 hours. The reaction progress was monitored by TLC (Thin-layer chromatography), and the yields of the products were determined by 1H-NMR and 13C NMR analysis.

Oxidation of Benzyl Alcohol Compounds in the Presence of Carbon Hybrid Supported Platinum Nanoparticles (Pt@CHs) in Oxygen Atmosphere.

A novel catalyst which carbon hybrid supported platinum nanoparticles were synthesized by our group for the oxidation of benzyl alcohol derivatives. In this study, this catalyst was utilized for the oxidation of benzyl alcohol derivatives to benzaldehyde compounds in aqueous toluene at 80 °C. The benzaldehyde derivatives were synthesized in high yields and mild conditions in the presence of the catalyst by the developed method. Additionally, the prepared nanoparticles have been characterized by Transmission Electron Microscopy (TEM), the high-resolution electron micrograph (HR-TEM), X-ray Photoelectron Spectroscopy (XPS), and X-ray Diffraction (XRD). The mean particle size of the nanoparticles determined by the XRD technique was found to be 2.83 nm in parallel with TEM analysis. TEM analysis also indicated that the Pt nanoparticles were evenly dispersed on the support material. Finally, the Pt@CHs catalyst was shown also stable and reusable for the oxidation reaction, providing ≤95% conversion after its 3rd consecutive use in the oxidation reaction of various compounds.

Composites of Palladium-Nickel Alloy Nanoparticles and Graphene Oxide for the Knoevenagel Condensation of Aldehydes with Malononitrile.

Herein, we have described uniformly dispersed palladium-nickel nanoparticles furnished on graphene oxide (GO-supported PdNi nanoparticles) as a powerful heterogeneous nanocatalyst for the promotion of Knoevenagel reaction between malononitrile and aromatic aldehydes under mild reaction conditions. The successful characterization of PdNi nanoparticles on the GO surface was shown by X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and TEM. GO-supported PdNi nanoparticles, which are used as highly efficient, stable, and durable catalysts, were used for the first time for the Knoevenagel condensation reaction. The data obtained here showed that the GO-supported PdNi nanocatalyst had a unique catalytic activity and demonstrated that it could be reused five times without a significant decrease in the catalytic performance. The use of this nanocatalyst results in a very short reaction time under mild reaction conditions, high recyclability, excellent catalytic activity, and a straightforward work-up procedure for Knoevenagel condensation of malononitrile and aromatic aldehydes.

9,10-Dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones: Synthesis and Investigation of Their Effects on Carbonic Anhydrase Isozymes I, II, IX, and XII.

N-substituted maleimides were synthesized from maleic anhydride and primary amines. 1,4-Dibromo-dibenzo[e,h]bicyclo-[2,2,2]octane-2,3-dicarboximide derivatives (4a-f) were prepared by the [4+2] cycloaddition reaction of dibromoanthracenes with the N-substituted maleimide derivatives. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the new derivatives were assayed against the human (h) isozymes hCA I, II, IX, and XII. All tested bicyclo dicarboximide derivatives exhibited excellent inhibitory effects in the nanomolar range, with Ki values in the range of 117.73-232.87 nM against hCA I and of 69.74-111.51 nM against hCA II, whereas they were low micromolar inhibitors against hCA IX and XII.