Supported Gold Nanoparticle-Catalyzed Selective Reduction of Multifunctional, Aromatic Nitro Precursors into Amines and Synthesis of 3,4-Dihydroquinoxalin-2-Ones.

The synthesis of 3,4-dihydroquinoxalin-2-ones via the selective reduction of aromatic, multifunctional nitro precursors catalyzed by supported gold nanoparticles is reported. The reaction proceeds through the in situ formation of the corresponding amines under heterogeneous transfer hydrogenation of the initial nitro compounds catalyzed by the commercially available Au/TiO-EtSiH catalytic system, followed by an intramolecular C-N transamidation upon treatment with silica acting as a mild acid. Under the present conditions, the Au/TiO-TMDS system was also found to catalyze efficiently the present selective reduction process.

Polyoxometalate-Driven Ease Conversion of Valuable Furfural to -,-4,5-Diaminocyclopenten-2-ones.

We investigated the catalytic efficacy of silicotungstic acid (HSiWO) polyoxometalate (POM) toward the reaction between furfural and amines that selectively yields -,-4,5-substituted-diaminocyclopenten-2-ones (-DACPs). HSiWO facilitates the synthesis of a library of -DACPs with loadings as low as 0.05 mol %, in open air, without additives, in short times and good to high isolated yields.

Direct and Indirect Chemiluminescence: Reactions, Mechanisms and Challenges.

Emission of light by matter can occur through a variety of mechanisms. When it results from an electronically excited state of a species produced by a chemical reaction, it is called chemiluminescence (CL). The phenomenon can take place both in natural and artificial chemical systems and it has been utilized in a variety of applications.

Diversity and Resistance Profiles of Human Non-typhoidal spp. in Greece, 2003-2020.

spp. is one of the most common foodborne pathogens in humans. Here, we summarize the laboratory surveillance data of human non-typhoidal salmonellosis in Greece for 2003-2020.

Selective C-H Allylic Oxygenation of Cycloalkenes and Terpenoids Photosensitized by [Cu(Xantphos)(neoc)]BF.

We present herein for the first time the use of the [Cu(Xantphos)(neoc)]BF as a photocatalyst for the selective C-H allylic oxygenation of cycloalkenes into the corresponding allylic hydroperoxides or alcohols in the presence of molecular oxygen. The proposed methodology affords the products at good yields and has also been applied successfully to several bioactive terpenoids, such as geraniol, linalool, β-citronellol, and phytol. A mechanistic study involving also kinetic isotope effects (KIEs) supports the proposed singlet oxygen-mediated reaction.