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An eco-friendly, sustainable and practical method for the efficient preparation of 5-organylselanyl uracils through the electrochemical selenylation of uracils and diorganyl diselenides at room temperature under oxidant- and external electrolyte-free conditions was developed.

A safe, practical and eco-friendly method for the switchable synthesis of sulfoxides and sulfones through visible-light-initiated oxygenation of sulfides at ambient temperature under transition-metal-, additives-free and minimal solvent conditions. The synergistic catalytic efforts between CF3SO2Na and 2-butoxyethyl ether represents the key promoting factor for the reaction.

Aerobic oxidation using pure dioxygen gas as the oxidant has attracted much attention, but its application in synthetic chemistry has been significantly hampered by the complexity of catalytic system and potential risk of high-energy dioxygen gas. By employing 1,2-diethoxyethane as a catalyst and ambient air as an oxidant, an efficient protocol for the construction of various aryl-alkyl and diaryl ketones through oxidative cleavage of gem-disubstituted aromatic alkenes under minimal solvent conditions has been achieved.

The development of eco-friendly and switchable catalytic systems for the conversion of a sole raw-material into distinct high-value products is a particularly attractive concept and a daunting synthetic challenge. In the present work, the first example of efficient and selective oxidation of sulfides to sulfones and sulfoxides using molecular oxygen under clean conditions was established.

An eco-friendly and economical route for the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) with atmospheric dioxygen as the sole oxidant under acid-, base-, metal-, and external initiator-free conditions in minimal solvent was reported. In the present reaction, the 1,2-diethoxyethylane has a dual role: reaction medium and free-radical initiator. The FDCA easily crystallizes during the reaction and was simple purified via recrystallization to provide the pure FDCA.

By employing atmospheric dioxygen as the sole oxidant, an eco-friendly protocol for the clean preparation of various aromatic (cyclic) ketones through phosphinate-promoted oxidation of benzylic Csp...

A direct and efficient palladium-catalyzed reductive coupling reaction of nitroarenes with phenols has been developed. A series of N-cyclohexylaniline derivatives was easily and efficiently obtained in moderate to good yields via C–N bond formation by the simple use of safe and inexpensive sodium formate as the hydrogen donor.

An economic, safe, practical, and environmentally benign protocol for the oxidation of aldehydes to carboxylic acids and acid anhydrides with ambient air as the sole oxidant was developed. This oxidation is operationally simple and external catalyst-, initiator-, and base-free, with outstanding functional group tolerance (moisture-, acid-, base-, and oxidant-sensitive groups). It also provides a practical protocol for large scale synthesis (>100 g), late-stage modification of polyfunctional compounds, and one-pot sequential transformation starting from aldehydes.

We describe an eco-friendly, practical and operationally simple procedure for the bis(methoxypropyl) ether-promoted oxidation of aromatic alcohols into aromatic carboxylic acids and aromatic ketones with atmospheric dioxygen as the sole oxidant. This chemical process is clean with high conversion and good selectivity, and an external initiator, catalyst, additive and base are not required. The virtue of this reaction is highlighted by its easily available and economical raw materials and excellent functional group tolerance (acid-, base- and oxidant-labile groups).

A practical and environmentally attractive methodology for the direct diversification of N-heterocycles at ambient temperature under open-air conditions was developed. The obvious advantage of the process is that no toxic reagent, transition metal, base or other additive is employed, thus greatly reducing costs, facilitating post-reaction neutralization and purification and minimizing the environmental impact.

Without using any base and organic solvent, an environmentally benign methodology was developed for the aqueous synthesis of various functionalized quinolin-2(1H)-ones at ambient temperature. The developed protocol has a wide substrate scope, excellent to quantitative yields, short reaction time (1–8 min), operational simplicity, reusable reaction medium and avoids further chromatographic purification. More importantly, this methodology is markedly greener than the traditional routes with an E-factor of 1.6 and eco-scale score of 89.5.

The control of a reaction that can produce multiple products from the same starting material is a highly attractive and challenging concept in organic synthesis. An efficient protocol for the selective synthesis of α-mono or α,α′-dihalo ketones via a water-controlled three-component thiourea-catalyzed cascade reaction of unactivated alkynes, 1,3-dihalo-5,5-dimethylhydantoin and water has been developed. α-Monohaloketones were obtained in aqueous acetone at 45 °C; conversely, α,α′-dihalo ketones were formed with pure water as the sole solvent at room temperature.

Without employing any base and organic solvent, an economical, practical and eco-friendly protocol has been developed for the one-pot synthesis of various functionalized 2-sulfonylquinolines from easily accessible starting materials in water under open-air conditions. Compared with conventional heating conditions, the use of ultrasound techniques not only improves the reaction efficiency and enhances the reaction rate but also minimizes the side reactions. This process has a broad substrate scope, mild reaction conditions, good yields, excellent chemo- and regioselectivities, operational simplicity, ease of scale-up and high energy efficiency. In addition, the process is remarkably greener than the previous routes with an atom economy of 70.7%, an E-factor of 1.17 and an eco-scale score of 71.

Rolling circle amplification is an isothermal method for amplifying DNA. The technique rapidly synthesizes a long (more than 1000 bases), linear, tandemly-repetitive single-stranded DNA chain by a short (less than 100 bases long) circular template. The reaction may proceed in either linear or exponential amplification modes and may provide copies of the circle up to 104-fold. The robustness, speed, and sensitivity of the rolling circle amplification strategies have gained widespread application in DNA and protein assays, single nucleotide polymorphism, in situ signal amplification, drug discovery, and nanotechnology.

A new, simple and sensitive fluorescence strategy was developed for the trypsin assay based on copper nanoparticles (CuNPs) and its different fluorescence response toward trypsin-catalyzed hydrolysis of cytochrome c (Cyt c). Polythymine (poly T)-templated CuNPs served as effective fluorescent probes. Cyt c is well-known to act as a quencher. However, herein, a low concentration of Cyt c was designed specially to act as the substrate of trypsin to avoid the quenching effects by electron transfer from Cyt c to CuNPs. In the presence of trypsin, Cyt c hydrolyzes to small peptides, releasing free cysteine residues. Nonfluorescent coordination complexes were formed upon exposure to free cysteine residues by a metal-ligand bond between Cu atoms and sulfur atoms, leading to a decreased fluorescence response to CuNPs. This novel method for the quantitative determination of trypsin has a linear detection range from 0.25 μg mL(-1) to 1000 μg mL(-1) and a relatively low detection limit of 42 ng mL(-1). To the best of our knowledge, this is the first application of the trypsin-catalyzed hydrolysis reaction of Cyt c to produce quenching effect in bioanalysis, which provided a novel approach for the biochemical sensing strategy.