Composite carbon quantum dots (CQDs), characterize as zero-dimensional carbon nanomaterial, play a crucial role in accelerating the separation of photoelectron-hole pairs within photocatalysts. Moreover, they introduce abundant oxygen vacancies (OVs) and facilitate the formation of new defect levels. Therefore, in this study, CA/BiOCl-x was synthesized via the hydrothermal method using carbon aerogel (CA) as the precursor for CQDs endowed with visible light activity. Through the degradation of tetracycline hydrochloride (TCH), the results demonstrate that CA/BiOCl-6 % exhibits the most prominent photocatalytic efficiency, showcasing a degradation rate of TCH under visible light irradiation fourfold higher than that of pristine BiOCl. Furthermore, the degradation activity is significantly enhanced under full spectrum irradiation, achieving a degradation rate of similar to 100 %. The observation indicated efficient integration of CQDs into BiOCl through C = O, introducing abundant OVs. Electrochemical analysis revealed that the enhancement of catalyst recombination significantly augmented both the lifetime of photogenerated carriers and the intensity of photocurrent. Active species quenching experiments indicated the superior role of superoxide radical (center dot O-2(-)) in CA/BiOCl mediated TCH degradation. Liquid chromatography-mass spectrometry further confirmed the degradation pathways of contaminants. This study provides novel insights into the development of efficient photocatalysts for remediations of organic pollutants.

An iodoarene-driven electroreductive remote C(sp(3))-H arylation of unsymmetrical 1-(o-iodoaryl)alkyl ethers with cyanoarenes for the site selective synthesis of alpha-(hetero)aryl ethers is developed. With the introduction of cyanoarenes as both aryl sources and electron transfer mediators, this method includes an iodoarene-driven strategy to enable the regiocontrollable formation of two new bonds, one C(sp(2))-H bond, and one C(sp(2))-C(sp(3)) bond, in a single reaction step through the sequence of halogen atom transfer (XAT), hydrogen atom transfer (HAT), radical-radical coupling, and decyanation.

1,4-dioxane is a potential carcinogen in water and is difficult to deal with due to its robust cycloether bond and complete miscibility with water. To remove 1,4-dioxane in an economically viable and environmentally friendly way, a series of carbon aerogels were synthesized as adsorbents for 1,4-dioxane. The experiment results showed that adsorption performances were closely related to the preparation conditions of carbon aerogels, such as the molar ratio, heating rate, pyrolysis temperature and residence time, which were carefully controlled. Scanning electron microscope analysis revealed the presence of a three-dimensional porous network structure in carbon aerogels. Brunauer–Emmett–Teller analysis results demonstrated an increase in specific surface area (673.89 m2/g) and total pore volume after carbonization, with an increase in mesoporous porosity and a decrease in microporosity. When considering each variable individually, the highest specific surface area of prepared carbon aerogels was achieved at a pyrolysis temperature of 800 °C, a holding time of 1 h, and a heating rate of 2 °C/min. Under optimal experimental conditions, the adsorption removal of 1,4-dioxane by carbon aerogels exceeded 95%, following quasi-second-order kinetics and Langmuir isothermal adsorption isotherms, indicating that monolayer adsorption on the surface of carbon aerogels occurred. The maximum adsorption capacity obtained was 67.28 mg/g at a temperature of 318 K, which was attributed to the presence of a large proportion of mesopores and abundant micropores simultaneously in carbon aerogels. Furthermore, with the interference of chlorinated solvents such as trichloroethylene (TCE), the removal efficiency of 1,4-dioxane had no obvious inhibition effect. Regeneration experiments showed that after five continuous cycles, the carbon aerogels still kept a comparable adsorption capacity, which illustrates its potential application in 1,4-dioxane-polluted water purification.

Electrochemical transition metal catalysis has been regarded as a synthetically attractive method for the construction of diverse organic frameworks because it obviates the use of chemical redox reagents. Herein, we report an elegant rhodium-catalyzed electrochemical [2 + 2 + 2] cyclotrimerization of 1,3-butadiynes for the regioselective synthesis of structurally diverse hexasubstituted arenes in an undivided cell. This methodology features excellent regioselectivity, good functional group tolerance, and high atom economy. Mechanistic studies show that the formation of five-membered C-Rh metallacycle species is crucial, and it would sequentially undergo consecutive coordination, migratory insertion and reductive elimination to deliver the desired arenes. A cooperative rhodium-catalyzed electrochemical 1,3-butadiyne [2 + 2 + 2] cyclotrimerization to selectively produce hexasubstituted arenes is presented.

A visible-light-driven photoredox dialkylation of styrenes with alpha-carbonyl alkyl bromides and pyridin-1-ium salts for the synthesis of polysubstituted 1,4-dihydropyridines is reported. This reaction enables the formation of two new C-(sp(3))-C-(sp(3)) bonds in a single reaction step and provides a strategy that employs pyridin-1-ium salts as the functionalized alkylating reagents via dearomatization to directly trap the resulting alkyl radicals from radical addition of alkenes and then terminate the alkene dialkylation.

A palladium(0)-catalyzed β-C(sp3)-H arylation of silyl prop-1-en-1-ol ethers with aryl halides for the synthesis of α,β-unsaturated ketones is presented. In contrast to the reported β-C(sp3)-H arylation of ketones, the chemoselectivity of this current method relies on the Pd(0) catalytic systems and reaction temperatures: While using the Pd(dba)2/DavePhos/KF system at 80 °C resulted in β-C(sp3)-H monoarylation to produce β-monoarylated α,β-unsaturated ketones, harnessing the Pd(OAc)2/t-Bu XPhos/K2HPO4 system at 110 °C induced β-C(sp3)-H diarylation to afford β,β-diarylated α,β-unsaturated ketones. The method provides a versatile route that uses readily available ketone-derivatized α-nonsubstituted silyl prop-1-en-1-ol ethers as the alkene sources and is characterized by a good functional group compatibility, a broad substrate scope, and an excellent selectivity.

A cooperative nickel and photoredox reductive catalysisfor 1,4-dicarbofunctionalizationof 1,3-enynes with tertiary N-methylamines and organohalidesto produce tetrasubstituted allenes is presented. This method enablesthe generation of the aminoalkyl C(sp(3))-centered radicalsby site selective cleavage of the N-methyl C(sp(3))-H bonds in tertiary N-methylaminesand is extended to alkyl bromides as the electrophilic terminatingregents. Mechanistic studies indicate that the reaction involves aradical process and a Ni-0/Ni-I/Ni-III catalytic cycle.

A new cooperative nickel reductive catalysis and N,N-dimethylformamide-mediated strategy for umpolung CS radical reductive cross coupling of S-(trifluoromethyl)arylsulfonothioates with alkyl halides to produce alkyl aryl thioethers is described. This reaction features excellent selectivity, wide functionality tolerance, broad substrate scope, and facile late-stage modification of biologically relevant molecules. Mechanistic studies recognize initial generation of an amidyl radical anion via thermoinduced reduction of DMF with Sn, followed by umpolung reduction and single electron transfer of the nucleophilic sulfonyl moiety to form a sulphydryl radical and engage the Ni0/NiI/NiIII/NiI catalytic cycle.

The radical-mediated reductive functionalization of aryl halides has been extensively studied. However, the related radical-mediated intermolecular reductive 1,2-diarylation of alkenes, using aryl halides as aryl radical sources, remains unexplored. Herein, a new electrophotocatalytic intermolecular reductive 1,2-diarylation of alkenes is reported using aryl halides and cyanoaromatics to produce polyarylated alkanes. Using synergistic cathodic reduction and visible-light photoredox catalysis, various electron-rich and electron-deficient aryl halides are combined with various alkenes and cyanoaromatics to characterize the broad substrate scope, excellent functional group compatibility, and excellent selectivity of this reaction. Mechanistic investigations reveal that this reaction may proceed via a radical process initiated by the reductive generation of aryl radicals from aryl halides and terminated by radical-radical coupling with cyanoaromatic radical anions.

A new method involving mild acryl transient-chelating-group-controlled stereoselective Rh(i)-catalyzed silylative aminocarbonylation of 2-alkynylanilines with CO and silanes is presented for producing (Z)-3-(silylmethylene)indolin-2-ones. Upon using an acryl transient chelating group, 2-alkynylanilines undergo an unprecedented alkyne cis-silylrhodation followed by aminocarbonylation to assemble (Z)-3-(silylmethylene)indolin-2-ones. Mechanistic studies show that acryl transient chelating effects result in the key alkyne cis-silylrhodation process.

Site-selective copper-catalyzed fluorosulfonamide-directedremote benzylic C(sp3)–Holefination reactions for producingfunctionalized internal alkenes are depicted.

A nickel-catalyzed C-S reductive cross-coupling of alkyl halides with arylthiosilanes for producing alkyl aryl thioethers is developed. This reaction is initiated by umpolung transformations of arylthiosilanes followed by C-S reductive cross-coupling with alkyl halides to manage an electrophilic alkyl group onto the electrophilic sulfur atom and then construct a C(sp3)-S bond, and features exquisite chemoselectivity, excellent tolerance of diverse functional groups, and wide applications for late-stage modification of biologically relevant molecules.

Cadmium (Cd) contamination poses a serious problem in paddy soils because of its high health risk through soilfood chain transfer. To evaluate the effect of biochar-based fertilizer on Cd uptake, soil and rice quality, biochar amendment at rates from 0 to 15 t/hm(2) was conducted in Cd polluted paddy soils. For successive two rice seasons, biochar treatments greatly reduced rice Cd and soil bioavailable Cd content. Furthermore, the concentration of bioavailable Cd decreased accordingly with the increase of biochar content. When soil properties, such as pH and soil organic carbon (SOC) were significantly improved, grow indexes of rice, especially for the late rice, would be partly improved. Most of the bioavailable Cd was immobilized in root, only a small partition of Cd was transferred to brown rice. The main stage for Cd accumulation was from heading stage to harvest stage.

An unprecedented palladium-catalyzed asymmetric carbonylation of ArI with carbon monoxide (CO) to expand a class of atroposelective cyclic and acyclic amides in good yields with high enantioselectivities has been reported.

Owing to their easy availability and cheapness, simple alkyl chlorides are good raw materials for introducing complex polychlorinated groups. Polychlorinated hydrocarbons units, such as di- or trichloromethyl groups, not only widely found in pesticide and bioactive molecule, but also can be as a precursor to converted into different functional groups such as -COOH, -CHO and -CO. The direct polychloroalkylation reaction by using simple alkyl chlrides has been considered to be an important tool for synthesizing complex polychlorinated compounds. This review summarizes recent developments, especially free radical strategies, in the polychloroalkylation of different substrates (such as 2-acylpyridines, benzyl tertiary amines, alkenes, imine and 1,n-enynes). We hope that this review provides a new perspective on this field and also provides a reference to develop environmentally friendly and sustainable methods.

Metal-free amino-assisted electrochemical intramolecular C–O or C–N couplings of amino-2-(2-aminoaryl)phenols are described.

Using terminal alkyne as a nontraditional one-carbon (C1) unit and silylborane as an external silicon pronucleophile, a relay palladium/copper-catalyzed silylative [5 + 1] benzannulation of 3-acetoxy-1,4-enynes for producing polysubstituted arylsilanes, especially including bioactive motif-based analogues, in a single reaction step through benzene ring skeleton assembly and silyl intermolecular incorporation cascades is developed. Mechanistic studies show that this reaction allows the terminal sp-hybridized carbon atom in terminal alkynes as a C1 unit via cleavage of two π-bonds and one C(sp)-H bond.

An efficient photocatalytic dual decarboxylative alkenylation of α,β-unsaturated carboxylic acids and alkyl N-hydroxyphthalimide (NHP) esters mediated by triphenylphosphine and sodium iodide has been developed. This protocol proceeds under 456-nanometer irradiation by visible blue light in the absence of transition metals or organic dye based photoredox catalysts. The reaction is successfully applied to a wide range of redox-active esters derived from aliphatic carboxylic acids (1°, 2° and 3°) and α-amino acids, enabling transformations of diverse α,β-unsaturated carboxylic acids to α,β-alkylated styrenes with high efficiency and excellent selectivity under mild conditions.

We here describe an alkynylative [5+1] benzannulation of 3-acetoxy-1,4-enynes with terminal alkynes, which enables both the construction of a benzene ring skeleton and intermolecular incorporation of an alkynyl group in a single reaction using Pd and Cu cooperative catalysts. The method represents efficient access to internal aryl alkynes through divergent functionalization of two terminal alkyne components: one alkyne serves as the one-carbon unit to realize the [5+1] benzannulation and the other alkyne as a nucleophile terminates the reaction.

Metal oxides (manganese oxide, MnO, manganese dioxide, MnO2, copper oxide, CuO, zinc oxide, ZnO and nickel oxide, NiO) doped carbon aerogel (CA) were prepared and used as catalysts in heterogeneous oxidation of phenol from aqueous solution in a three-dimensional (3D) electrode reactor. Textural characterization of metal oxides doped CA showed that the metal oxide nanoparticles are dispersed separately throughout the carbon matrix. The experimental results showed that phenol was degraded mainly by hydroxyl (•OH) radicals. The presence of metal oxides accelerated •OH radical generation. The •OH radical quantity depends on the type of metal oxide. The n-type semiconductor was more active than p-type semiconductor for •OH radical generation. Furthermore, acceleration effect of •OH radical generation catalyzed by metal oxides doped CA was investigated and demonstrated.