Role of coke media strategy in an adsorption-biological coupling technology for wastewater treatment performance, microbial community, and metabolic pathways features.

With the increase of wastewater discharge, the requirement of wastewater treatment technology is gradually increased. How to treat wastewater economically, while making the treatment process short, easy to manage and low running cost, is the focus of attention. Adsorption-biological coupling technology could make adsorption and biodegradation complement each other, which has coupled accumulation effect. In this study, with coke as the adsorbent, the efficiency of the adsorption-biological coupling reactor on the treatment of total phosphorus (TP), chemical oxygen demand (COD), and ammonia nitrogen (NH3-N) in domestic wastewater under different influent modes was investigated. Meanwhile, microbial community and metabolic pathways analysis of the reactor were carried out. Results showed that when the influent modes of the coupling reactor was once a day and the daily sewage treatment capacity was 2 L, the treatment efficiency of TP, COD, and NH3-N was the best. The removal rate of TP and NH3-N was 87.96% and 96.14%, respectively. The dominant phylum was Proteobacteria (39.84-44.49%), and the dominant genus was Sphingomonas (4.27-7.16%), and Gemmatimonas (1.27-3.58%). According to the metagenomic analysis, carbon metabolism process was evenly distributed in U (upper), M (middle), and L (lower) layers of the coupling reactor. Phosphate metabolism was mainly in the U layer at first, then in the M and L layers gradually. Carbon metabolism and phosphate metabolism provided sufficient energy for microbial degradation of pollutants. Nitrogen removal in the reactor mainly happened in the S and Z layers by nitrification (M00528) and denitrification (M00529), respectively.

Palladium-Catalyzed Allyl-Allyl Reductive Coupling of Allylamines or Allylic Alcohols with H2 as Sole Reductant.

Catalytic carbon-carbon bond formation building on reductive coupling is a powerful method for the preparation of organic compounds. The identification of environmentally benign reductants is key for establishing an efficient reductive coupling reaction. Herein an efficient strategy enabling H2 as the sole reductant for the palladium-catalyzed allyl-allyl reductive coupling reaction is described. A wide range of allylamines and allylic alcohols as well as allylic ethers proceed smoothly to deliver the C-C coupling products under 1 atm of H2. Kinetic studies suggested that the dinuclear palladium species was involved in the catalytic cycle.

Palladium-Catalyzed Carbonylative Difunctionalization of C=N Bond of Azaarenes or Imines to Quinazolinones.

Supporting information for this article is given via a link at the end of the document. By intercepting the acylpalladium species with C=N bond of azaarenes or imines other than free amines or alcohols, the difunctionalization of C=N bond was established via palladium-catalyzed carbonylation/nucleophilic addition sequence. This method is compatible with a diverse range of azaarenes and imines and allows for the efficient synthesis of a wide range of quinazolinones and derivatives. The synthetic utility has been demonstrated by one-step synthesis of evodiamine and its analogue with inexpensive starting materials.

Palladium-Catalyzed Hydrocarbonylative Cyclization Enabled by Formal Insertion of Aromatic C═N Bonds into Pd-Acyl Bonds.

An efficient new formal insertion strategy via combination of reductive elimination and oxidative addition sequence was reported, in which the transient N-acyliminium ions formed via hydrocarbonylation function as key intermediates. This strategy has enabled a novel palladium-catalyzed hydrocarbonylative cyclization of azaarene-tethered alkenes or dienes via sequential insertion of a C═C bond, CO, and a C═N bond into palladium-hydride bonds. This method provides a new and highly efficient synthetic approach to quinolizinones and its derivatives with extended π-conjugated systems, possessing tunable emission wavelengths and good photoluminescence capabilities.

Palladium-Catalyzed Regioselective Hydroaminocarbonylation of Alkynes to α,ß-Unsaturated Primary Amides with Ammonium Chloride.

α,ß-Unsaturated primary amides have found numerous applications in drug development, organic materials, and polymer sciences. However, the catalytic synthesis of α,ß-unsaturated primary amides via carbonylation of alkynes has long been an elusive endeavor. Here, we report a novel palladium-catalyzed hydroaminocarbonylation of alkynes with NH4Cl as the amine source, enabling the highly chemo- and regioselective synthesis of α,ß-unsaturated primary amides. A variety of alkynes, including aromatic alkynes, aliphatic alkynes, terminal alkynes, internal alkynes, as well as diynes with various functional groups, react well. The method turns the parasitic noncoordination ability of ammonium salts into a strategic advantage, enabling the gram-scale reaction to be performed in the presence of 0.05 mol % of catalyst with excellent selectivity.

Palladium-catalyzed regiodivergent hydroaminocarbonylation of alkenes to primary amides with ammonium chloride.

Palladium-catalyzed hydroaminocarbonylation of alkenes for the synthesis of primary amides has long been an elusive aim. Here, we report an efficient catalytic system which enables inexpensive NH4Cl to be utilized as a practical alternative to gaseous ammonia for the palladium-catalyzed alkene-hydroaminocarbonylation reaction. Through appropriate choice of the palladium precursors and ligands, either branched or linear primary amides can be obtained in good yields with good to excellent regioselectivities. Primary mechanistic studies were conducted and disclosed that electrophilic acylpalladium species were capable of capturing the NH2-moiety from ammonium salts to form amides in the presence of CO with NMP as a base.

Palladium-Catalyzed Hydrocarbonylative C-N Coupling of Alkenes with Amides.

An efficient palladium-catalyzed hydrocarbonylative C-N coupling of alkenes with amides has been developed. The reaction was performed via hydrocarbonylation of alkenes, followed by acyl metathesis with amides. Both intermolecular and intramolecular reactions proceed smoothly to give either branched or linear amides in high turnover number (3500) with NH4Cl or NMP·HCl as a proton source under the palladium catalysis. This reaction offers a catalytic convenient approach to deuterated amides when inexpensive NMP·DCl served as a deuterium source.

Palladium-Catalyzed Dehydrogenative Difunctionalization of Aminoalkenes with Aminals as Oxidants and Electrophiles.

A novel palladium-catalyzed aminomethylamination of aminoalkenes with an aminal, functioning not only as an aminomethylation reagent but also as an oxidant, was developed. This direct and operationally simple protocol provides a fundamentally novel and unique approach toward the synthesis of 2-(2-aminoethyl)indoles and 2-(2-aminoethyl)pyrrolidines, which are important building blocks in synthetic organic chemistry. The unity of this method was highlighted by the rapid synthesis of Alosetron, a drug used for the treatment of irritable bowel syndrome.

A high-performance and simple method for rapid and simultaneous determination of dihydroxybenzene isomers.

A novel idea on the basis of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (THPP) functionalized carbon nanotubes (CNTs) film was developed to simulate the chromatographic separation, which was able to rapidly and simultaneously detect dihydroxybenzene isomers based on their different oxidation potentials and corresponding currents. The mechanism involved in the recognition and isolation of the dihydroxybenzene isomers was explored and confirmed by UV spectra and density functional theory. It was proven that the current method for simultaneously detecting and isolating dihydroxybenzene isomers was ascribed to the priority of porphyrin film to induce oxidation of the three kinds of isomers, and the priority depends to a large extent on the different tendencies of dihydroxybenzene to interact with the peripheral hydroxyl group and with the extended π-conjugated ring of porphyrin. Most important of all, porphyrin functionalized CNTs film allows for the formation of well-defined interface and provides an advantageous and high-performance platform for the simultaneous determination and isolation of dihydroxybenzene isomers.

Highly dispersive Ag nanoparticles on functionalized graphene for an excellent electrochemical sensor of nitroaromatic compounds.

A facile carbon radical reaction procedure and a chemical reduction method were proposed to synthesize Ag nanoparticles on functionalized graphene with uniform, high dispersion and excellent stability. The resultant material showed excellent electrocatalytic activity to nitroaromatic compounds and high sensitivity to the detection of nitroaromatic compounds.

Heterogeneous consecutive electron transfer at graphite electrodes under steady state.

In this report, the theory based on thin-layer cyclic voltammetry (TLCV) for consecutive electron transfer (ET) across the interface between two immiscible electrolyte solutions (ITIES) is well developed and experimentally verified. The voltammetric responses to multistep electron transfer at the ITIES are predicted by numerical simulations. Moreover, the impact of empirical parameters on the shape of the multistep current-voltage curve has been examined. The results obtained not only give information regarding the effect of the concentration ratio of the reactants in two phases and the thin-layer thickness on multistep electron transfer, but also prove the excellent agreement between simulations and experiments. The model system of two-step electron transfer of ZnTPP/[Fe(CN)6]4⁻ was studied, indicating that the Bulter-Volmer (B-V) theory is suitable for the consecutive electron transfer. Thus, TLCV is demonstrated to be a useful means for investigating the kinetics of heterogeneous consecutive ET.