Controlling and Tuning the Dispersion Properties of Calcined Kaolinite Particles in Various Organic Solvents via the Modification Method Using Triethoxyvinylsilane and 3-Mercaptopropionic Acid.

The surface of calcined kaolinite particles underwent chemical modification using Vinyltriethoxysilane (VTMS) and 3-mercaptopropionic acid (3-MPA). The grafting ratio of VTMS on the calcined kaolinite surface was adjusted by varying its quantity. FT-IR analysis revealed the initial grafting of VTMS onto the kaolinite surface, resulting in the formation of a C=C reactive site on the surface.

Unsupported MoS-Based Catalysts for Bio-Oil Hydrodeoxygenation: Recent Advances and Future Perspectives.

In recent years, unsupported MoS-based catalysts have been reported as promising candidates in the hydrodeoxygenation (HDO) of bio-oil. However, preparing MoS-based catalysts with both high activity and good stability for HDO reaction is still challenging and of great importance. Hence, this mini-review is focused on the recent development of unsupported MoS-based HDO catalysts from the understanding of catalyst design.

Highly selective enrichment of Au using enaminone covalent organic polymers (COP).

The second recovery of gold has fundamental environmental and economic significance. In this study, an enaminone covalent organic polymer (COP) was synthesized and used to recover gold from secondary resources. The ketene covalent organic polymer (COP) possessed good gold adsorption performance, and the best adsorption capacity could reach up to 1945 mg g at 298 K, which was superior to traditional adsorbents.

Electrochemical Synthesis of Benzo[]imidazole via Intramolecular C(sp)-H Amination.

An electrochemical dehydrogenative amination for the synthesis of benzimidazoles was developed. This electrosynthesis method could address the limitations of the C(sp3)-H intramolecular amination synthesis reaction and provide novel access to obtain 1,2-disubstituted benzimidazoles without transition metals and oxidants. Under undivided electrolytic conditions, various benzimidazole derivatives could be synthesized, exhibiting functional group tolerance.

Electrochemical HI-mediated Intermolecular C-N Bond Formation to Synthesize Imidazoles from Aryl Ketones and Benzylamines.

An efficient and novel electrochemical oxidative tandem cyclization of aryl ketones and benzylamines for the synthesis of 1,2,4-trisubstituted-(1)-imidazoles has been developed under metal- and oxidant-free conditions. This direct C-N bond formation strategy, with a broad functional group tolerance, affords the desired imidazoles in moderate to excellent yields.

Preparation of a porous graphite felt electrode for advance vanadium redox flow batteries.

Rapid mass transfer and great electrochemical activity have become the critical points for designing electrodes in vanadium redox flow batteries (VRFBs). In this research, we show a porous graphite felt (GF@P) electrode to improve the electrochemical properties of VRFBs. The generation of pores on graphite felt electrodes is based on etching effects of iron to carbon.

Metal-Free, N-Iodosuccinimide-Induced Regioselective Iodophosphoryloxylation of Alkenes with P(O)-OH Bonds.

A simple and efficient method for the regioselective iodophosphoryloxylation of alkenes with P(O)-OH bonds has been established by using NIS (N-iodosuccinimide) as the iodination reagent under transition-metal-free conditions. The present protocol is compatible with different functional groups, and suitable for various alkenes and P(O)-OH compounds. A variety of functionalized β-iodo-1-ethyl phosphinic/phosphoric acid esters are obtained in good to excellent yields, which could be further transformed to diversified building blocks for the synthesis of bioactive compounds, pharmaceuticals and functional materials.

Electrochemical Oxidative Intramolecular N-S Bond Formation: Synthesis of 3-Substituted 5-Amino-1,2,4-Thiadiazoles.

A facile and efficient protocol for the synthesis of 3-substituted 5-amino-1,2,4-thiadiazoles has been developed through the electro-oxidative intramolecular dehydrogenative N-S bond formation of imidoyl thioureas. Various 1,2,4-thiadiazole derivatives were synthesized in good to excellent yields with broad substrate scope and excellent functional group tolerance under catalyst- and oxidant-free electrolytic conditions at room temperature.

One-Pot Synthesis of 5-Acyl-1,2,3-Thiadiazoles from Enaminones, Tosylhydrazine, and Elemental Sulfur under Transition-Metal-Free Conditions.

I/dimethyl sulfoxide (DMSO)-mediated C-S, S-N, and C-N bond cross-coupling cyclization reaction for the synthesis of 5-acyl-1,2,3-thiadiazoles from enaminones, tosylhydrazine, and elemental sulfur has been developed under transition-metal-free conditions. This strategy is operationally simple, compatible with a wide range of functional groups, and provides the desired products in moderate to excellent yields.

Copper-Catalyzed Diphenylation of P(O)-OH Bonds with Cyclic Diaryliodonium Salts.

A copper-catalyzed diphenylation of P(O)-OH bonds with cyclic diaryliodonium salts is described. Valuable 2'-iodo substituted biaryl phosphinic/phosphoric acid esters were obtained in good to excellent yields, which could be further transformed to diversified building blocks for the synthesis of bioactive compounds, pharmaceuticals and functional materials.

Visible-light-mediated difunctionalization of vinylcyclopropanes for the synthesis of 1-sulfonylmethyl-3,4-dihydronaphthalenes.

An efficient method for visible-light-mediated sulfonylation/arylation of the C-C σ-bond in vinylcyclopropanes with sulfonyl chlorides to synthesize 1-sulfonylmethyl-substituted 3,4-dihydronaphalenes has been developed. A radical-type pathway has been proved in this transformation. This difunctionalization procedure shows a series of advantages, such as the use of commercially and easily available sulfonyl chlorides, mild conditions, and eco-friendly energy.

Synthesis of 2-Acyl-3,4-dihydronaphthalenes by Silver-Promoted Oxidative C-C σ-Bond Acylation/Arylation of Alkylidenecyclopropanes with α-Ketoacids.

A novel and efficient AgNO-facilitated oxidative C-C σ-bond difunctionalization of alkylidenecyclopropanes with α-ketoacids for preparing 2-acyl-substituted 3,4-dihydronaphthalenes is developed. This radical acylation/arylation transformation proceeds via decarboxylation of the α-ketoacid, acylation of the carbon-carbon double bond, cleavage of the carbon-carbon σ-bond, and cyclization with a connected aromatic ring and offers a mild and facile strategy for acylation/arylation of carbon-carbon σ-bonds with an acyl radical and an aromatic ring to build two new carbon-carbon bonds. This method uses an inexpensive oxidant, features a wide substrate scope, and is operationally simple.

Oxidative radical ring-opening/cyclization of cyclopropane derivatives.

The ring-opening/cyclization of cyclopropane derivatives has drawn great attention in the past several decades. In this review, recent efforts in the development of oxidative radical ring-opening/cyclization of cyclopropane derivatives, including methylenecyclopropanes, cyclopropyl olefins and cyclopropanols, are described. We hope this review will be of sufficient interest for the scientific community to further advance the application of oxidative radical strategies in the ring-opening/cyclization of cyclopropane derivatives.

Visible-Light-Catalyzed C-C Bond Difunctionalization of Methylenecyclopropanes with Sulfonyl Chlorides for the Synthesis of 3-Sulfonyl-1,2-dihydronaphthalenes.

A novel visible-light-catalyzed sulfonylation/arylation of carbon-carbon σ-bond with sulfonyl chlorides for the synthesis of 3-sulfonylated 1,2-dihydronaphthalenes is developed. This difunctionalization proceeds via a sequence of C═C bond sulfonylation, C-C σ-bond cleavage, and intramolecular cyclization, and the experiment result shows that the C-C σ-bond difunctionalization reaction includes a radical process. This strategy provides a simple and convenient route for difunctionalization of C-C bonds with an aromatic carbon and a sulfonyl radical by one-pot construction of a C-S bond and a new C-C bond.

Silver-mediated oxidative C-C bond sulfonylation/arylation of methylenecyclopropanes with sodium sulfinates: facile access to 3-sulfonyl-1,2-dihydronaphthalenes.

The novel AgNO3-mediated oxidative sulfonylation/arylation of a C-C σ-bond in methylenecyclopropanes with sodium sulfinates to synthesize various 3-sulfonylated 1,2-dihydronaphthalenes is reported. This sulfonylation/arylation transformation proceeds via a sequence of sulfonylation, C-C σ-bond cleavage and intramolecular cyclization, and the experimental results show that the C-C σ-bond difunctionalization reaction includes a radical process. This strategy provides a simple and convenient route for the difunctionalization of C-C bonds with a phenyl ring and a sulfonyl radical via the one-pot construction of a C-S bond and a new C-C bond.

Oxidative C-C Bond Functionalization of Methylenecyclopropanes with Aldehydes for the Formation of 2-Acyl-3,4-dihydronaphthalenes.

A new FeCl- and DTBP (di- tert-butyl peroxide)-promoted oxidative ring-opening and cyclization of methylenecyclopropanes with aldehydes for the synthesis of 2-acyl-3,4-dihydronaphthalenes is presented. This oxidative cyclization reaction proceeds via a radical addition, ring-opening, and cyclization sequence facilitated by a Lewis acid, and it offers a practical and straightforward route for the oxidative cyclization of methylenecyclopropanes with an aromatic carbon and a C(sp)-H bond by simultaneously forming two new carbon-carbon bonds.

Visible-Light-Mediated Ipso-Carboacylation of Alkynes: Synthesis of 3-Acylspiro[4,5]trienones from N-(p-Methoxyaryl)propiolamides and Acyl Chlorides.

A novel visible-light-mediated ipso-carboacylation of N-(p-methoxyaryl)propiolamides with acyl chloride has been established for the synthesis of diverse 3-acylspiro[4,5]trienones with high selectivity and efficiency. This method represents a new difunctionalization of alkynes through cross coupling of the acyl chloride C-Cl bonds with an ipso-aromatic carbon by simultaneously forming two new carbon-carbon bonds and one carbon-oxygen double bond.

BuNI-Catalyzed Dehydrogenative Coupling of Diaryl Phosphinic Acids with C(sp)-H Bonds of Arenes.

An efficient phosphorylation of C(sp)-H bonds of arenes with diaryl phosphinic acids via BuNI-catalyzed dehydrogenative coupling has been developed. This transformation proceeds efficiently under transition-metal-free reaction conditions and represents a straightforward method to prepare valuable organophosphorus compounds from readily available arenes and diaryl phosphinic acids.

Metal-Free Oxidative C-C Bond Functionalization of Methylenecyclopropanes with Ethers Leading to 2-Substituted 3,4-Dihydronaphthalenes.

A novel metal-free oxidative ring-opening/cyclization of methylenecyclopropanes with ethers was established for the synthesis of diverse 2-substituted 3,4-dihydronaphthalenes with high selectivity and efficiency. This oxidative cyclization is achieved by C(sp)-H functionalization, ring-opening, and cyclization, and this method represents a new example of methylenecyclopropane oxidative cyclization with an aromatic carbon and a C(sp)-H bond by simultaneously forming two new carbon-carbon bonds.

Enantiomeric separation of oxybutynin by recycling high-speed counter-current chromatography with hydroxypropyl-β-cyclodextrin as chiral selector.

Recycling high-speed counter-current chromatography was successfully applied to the preparative separation of oxybutynin enantiomers. The two-phase solvent system consisted of n-hexane, methyl tert-butyl ether, and 0.1 mol/L phosphate buffer solution (pH = 5.

Studies on enantioselective liquid-liquid extraction of amino-(4-nitro-phenyl)-acetic acid enantiomers: modeling and optimization.

BINAP-metal complexes were prepared as extractant for enantioselective liquid-liquid extraction (ELLE) of amino-(4-nitro-phenyl)-acetic acid (NPA) enantiomers. The influence of process variables, including types of organic solvents and metal precursor, concentration of ligand, pH, and temperature on the efficiency of the extraction, were investigated experimentally. An interfacial reaction model was established for insightful understanding of the chiral extraction process.

Formal syntheses of (±)-platensimycin and (±)-platencin via a dual-mode Lewis acid induced cascade cyclization approach.

A mild and efficient dual-mode Lewis acid induced Diels-Alder (DA)/carbocyclization cascade cyclization reaction has been developed for construction of the tricyclic core of ent-kaurenoids in one pot with the aid of a theoretical study on the π,σ-Lewis acidities of a variety of Lewis acids. With ZnBr2 as the dual-mode Lewis acid, a series of substituted enones and dienes underwent DA/carbocyclization cascade cyclization reaction smoothly at room temperature and provided the tricyclic cyclized products in one pot with good yields and high diastereoselectivity. The tricyclic cyclized product has been successfully utilized as a common intermediate for formal syntheses of (±)-platensimycin and (±)-platencin.

2-Chloro-N'-(2,4-dichloro-benzyl-idene)benzohydrazide.

The title Schiff base compound, C(14)H(9)Cl(3)N(2)O, exists in a trans configuration with respect to the C=N bond and the dihedral angle between the two benzene rings is 13.5 (2)°. In the crystal, inter-molecular N-H⋯O hydrogen bonds link adjacent mol-ecules into extended C(4) chains propagating along the c-axis direction.

N'-(5-Bromo-2-hydroxy-benzyl-idene)-4-chloro-benzohydrazide.

The title Schiff base, C(14)H(10)BrClN(2)O(2), exists in a trans configuration with respect to the C=N bond and the dihedral angle between the two benzene rings is 0.8 (2)°. There is an intra-molecular O-H⋯N hydrogen bond in the mol-ecule, which generates an S(6) loop.