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We have successfully synthesized a series of bidentate ligands by utilizing 2-(trimethylsilyl)phenyl trifluorosulfonate as a precursor for the benzyl group. This method proceeded by inserting a polythiourea into the C═S π-bond, intramolecular ring proton migration, and ring opening. Salient features of this strategy are mild reaction conditions, a novel product structure, excellent stereochemistry, and a good functional group tolerance. Furthermore, a series of density functional theory calculations were performed to gain insights into the transfer mechanism.

A novel three-component cyclization carbonylation reaction of iodoarene-tethered propargyl ethers with amine and CO is reported. This palladium-catalyzed cascade reaction undergoes a sequence of oxidative addition, unsaturated bond migration, carbonyl insertion, and nucleophilic attack to deliver the benzofuran skeleton. Both aromatic amines and aliphatic amines could proceed smoothly in this transformation under one atm of CO.

We introduce switchable chemoselectivity strategies based on the hydrazone phosphaketene intermediate to synthesize three classes of 1,2,4-diazaphosphol derivatives. First, the five-membered heterocyclic P and O anion intermediates acted as nucleophilic agents in the selective construction of C–P and C–O bonds. Second, the phosphinidene served as a phosphorus synthon, allowing for the formation of C–P and C–N bonds. Finally, a stepwise mechanism, supported by DFT calculations, was invoked to explain the reaction selectivity.

Herein, we disclosed a highly chemoselective synthesis of quinoline-2-one and quinoline-2-thione derivatives using EtOS2K as the C1 source. Quinoline-2-one derivatives were synthesized selectively with NaCl as a catalyst in the solvent DMSO/H2O, while quinoline-2-thione derivatives were produced without the need for any catalyst in an environmentally friendly solvent EtOH/H2O. The reaction conditions were mild and had good functional group tolerance.

We report a highly regioselective three-component coupling reaction of styrene, CO gas, and an amine compound to synthesize multisubstituted α,β-unsaturated amides, which involves a palladium-catalyzed sequential 1,4-palladium migration, C(sp2)–H activation, carbonylation, and amination. Salient features of this strategy include the use of 1 atm of CO, excellent stereochemistry, and good functional group tolerance. Further, a series of control experiments and density functional theory calculations were performed to afford some insights for the transfer mechanism.

A nickel-catalyzed three-component tandem radical cyclization reaction of aryl bromides with 1,3-enynes and aryl boric acids to construct γ-lactam-substituted allene derivatives has been described. This protocol provides lactam alkyl radicals through the free radical cyclization process, which can be effectively used to participate in the subsequent multicomponent coupling reaction so that 1,3-enynes could directly convert into corresponding poly-substituted allene compounds. In addition, this efficient method enjoys a broad substrate scope and provides a series of 1,5-difunctionalized allenes in a one-pot reaction.

We report a cathodic reduction-dominated electrochemical approach for the hydrogenation of azobenzenes in dichloromethane. With cheap and readily available N,N-diisopropylethylamine as a catalytic mediator, the reaction proceeded smoothly in a simple undivided cell under constant-current electrolysis. A series of azobenzenes were successfully reduced to the corresponding hydrazobenzenes in moderate to high yields at room temperature. Preliminarily mechanistic studies indicate that solvent dichloromethane acts as a hydrogen source. The use of a common solvent as a hydrogen source, no need for stoichiometric mediators or metallic reductants, and mild conditions make this work a more straightforward and sustainable protocol for hydrogenation of azobenzenes.

The inverse vulcanization (IV) of elemental sulfur to generate sulfur-rich functional polymers has attracted much recent attention. However, the harsh reaction conditions required, even with metal catalysts, constrains the range of feasible crosslinkers. We report here a photoinduced IV that enables reaction at ambient temperatures, greatly broadening the scope for both substrates and products. These conditions enable volatile and gaseous alkenes and alkynes to be used in IV, leading to sustainable alternatives for environmentally harmful plastics that were hitherto inaccessible. Density functional theory calculations reveal different energy barriers for thermal, catalytic and photoinduced IV processes. This protocol circumvents the long curing times that are common in IV, generates no H2S by-products, and produces high-molecular-weight polymers (up to 460,000 g mol−1) with almost 100% atom economy. This photoinduced IV strategy advances both the fundamental chemistry of IV and its potential industrial application to generate materials from waste feedstocks.

A procedure utilizing [TBA][P(SiCl3)2] as P source for the synthesis of phosphinecarboxamides is presented. The synthesis involves the reaction of [TBA][P(SiCl3)2] with isocyanates. These compounds act as highly effective reagents for the subsequent phosphination of isocyanates, leading to the formation of phosphine(triscarboxamides). This reaction proceeds swiftly under mild and straightforward conditions, making it suitable for a wide range of commercially available isocyanates. A method has been developed for the reaction of isocyanates with [TBA][P(SiCl3)2] at room temperature to give the corresponding phosphinecarboxamide (RN(H)COPH2) in excellent yields. These compounds serve as excellent reactants for the subsequent hydrophosphination of isocyanates, resulting in the production of phosphine(triscarboxamides).

We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines or β-amino alcohols compounds using ruthenium catalysis. The reaction outcome is readily tuned by the simple addition of 4 ​Å molecular sieves (furfurylamines vs.β-amino alcohols) with high chemo-selectivity. The proposed reaction mechanism involves ruthenium-catalyzed hydrogen borrowing for the reduction of the imine intermediate and C–C bond cleavage of polyols viaa retro-aldol process. A series of arylamines was successfully transformed into the desired products with moderate to good yields.

Sulfur-rich polymers prepared by inverse vulcanization (IV), as a new chemistry and polymerization technique, have attracted increasing attention since their invention in 2013. Although extensive research has been devoted to IV, there is still huge scope for advance, particularly in terms of the practical applications of the resultant polymers. Previously SiO2-embedded sulfur-rich polymers from IV were reported as superhydrophobic, antibacterial and anti-corrosion coating materials. We report herein the improved properties of superhydrophobic and anti-corrosion functional materials prepared by embedding more hydrophobic TiN nanoparticles into sulfur-rich polymers. This method provides fluoride-free composite materials, which is important considering the possible hazard to humans and the environment and concerns of fluorine-containing olefins with long carbon chains. Static water contact angles (WCA) of up to 173.6 ± 1.1° as well as superior properties such as higher superhydrophobicity and anti-corrosion (97.2% coating protection rate) are achieved. The generated coating has good to excellent self-cleaning functions. This protocol not only improves the superhydrophobicity of the synthesized composites, but also provides a feasible method for the preparation of non-harmful and environmentally benign fluorine-free superhydrophobic anti-corrosion materials applied in marine industries.The synthesis of TiN-embedded sulfur-rich polymer micro-nanoparticles by inverse vulcanization reaction revealed the superhydrophobicity, corrosion resistance and antibacterial properties of the resultant composites, with WCA of the coating up to 173.6 ± 1.1°. This protocol provides a feasible method for the preparation of eco-friendly and environmentally benign fluorine-free superhydrophobic anti-corrosion materials in practical applications.

The free radical cyclization reaction is a promising strategy for ring framework formation. Herein, we report a copper-catalyzed tandem radical cyclization strategy for preparing substituted lactam derivatives. This reaction proceeds through a radical coupling approach, which not only allows a wide range of alkenes but also is quite compatible with the primary, secondary, and tertiary radicals. In addition, density functional theory calculations were performed to gain insights into the reaction mechanism.

An iron(II)-catalyzed bisphosphorylation cascade cycloisomerization of readily accessible γ-hydroxyl ynones and diphenylphosphine oxides is described. This strategy provides a variety of valuable polysubstituted bisphosphorylated dihydrofuran scaffolds via the construction of two C–P bonds and one C–O bond within a single procedure. This developed reaction system demonstrates good functional group compatibilities with considerably low catalyst consumption (as low as 1%), which could be further scaled up to gram quantities in satisfactory yields.

This report developed a method for the synthesis of C8-aminated pyrrolo-phenanthridines or -indoles by series orthoC(sp2)–H amination/ipsoC(sp2)–H or C(sp3)–H arylation. N-benzoyloxyamines, as electrophilic amination reagents, did not undergo an electrophilic substitution reaction with the pyrrole side, but they did undergo a site-selective C–H amination reaction with the benzene side via Pd/NBE catalysis. The C8-aminated pyrrolo-phenanthridines have strong fluorescence in solution and solid state. X-ray single crystal diffraction shows that the steric hindrance of amino and orthobenzene ring may inhibit aggregation-caused quenching (ACQ).

An efficient synthesis of C2-aryl pyrimidine derivatives via Pd-catalyzed Hiyama couplings has been developed. Various 2-chloro pyrimidines with electron-donating or electron-withdrawing groups as novel electrophile partners coupled well with trimethoxy(phenyl)silane and vinyltrimethoxysilane in the presence of CuCl and TBAF, providing desired products in good to excellent yields. This procedure showed good functional group tolerance, and the electronic and steric effects of 2-chloro pyrimidines seem to be negligible for the transformation.

In palladium/norbornene (Pd/NBE) chemistry, the “orthoeffect” has been proven to be a key factor in the process of β-carbon elimination to extrude NBE. Herein, we found that the o-iodoaniline protected by a p-methoxybenzenesulfonyl group can recover the “orthoeffect” and then undergo N–S bond cleavage with vinyl palladium, thus achieving a highly selective C–N coupling reaction in the Catallani–Lautens reaction system. On the basis of this discovery, a one-step synthesis of highly functionalized tricyclic indole derivatives was realized.

Herein, the sulfhydrylation and oxylation of olefins were completed under visible light irradiation with iodine as catalyst, which realized more economical and green chemical conversion because of the absence of metal complexes or organic dyes. A series of bifunctional modifications of olefins were achieved with good yields by using diol derivatives and water as nucleophiles. In addition, the control experiments show that the reaction is a free radical process. Sulfurization and oxidation of olefinsunder visible light inducement has been developed with iodine as a catalyst. β‐Alkoxysulfides and β‐Hydroxysulfides were obtained in good to high yields.

The direct synthesis of C4-acyl indoles deprived of C2 and C3 substituents has proven to be challenging, with scarce efficient synthetic routes being reported. Herein, we disclose a highly site-selective palladium-catalyzed C–H acylation for the construction of C4-acyl indoles via a Catellani–Lautens cyclization strategy. In addition, we systematically studied the orthoC–H acylation mechanism of iodoaniline through density functional theory (DFT) calculations and combined experimental results to elucidate the principle of high chemoselectivity brought by triazine benzoate as an acylation reagent.

A visible-light-promoted transfer hydrogenation of azobenzenes has been developed. In the presence of B2pin2and upon visible-light irradiation, the reactions proceeded smoothly in methanol at ambient temperature. The azobenzenes with diverse functional groups have been reduced to the corresponding hydrazobenzenes with a yield of up to 96%. Preliminary mechanistic studies indicated that the hydrogen atom comes from the solvent and the transformation is achieved through a radical pathway.

Herein, we report a non‐metal strategy for cyclization reactions of 2‐vinylanilines with/without isonitriles to synthesize 2‐aminoquinoline and 3‐aryl‐1H‐indole derivatives. A series of 2‐aminoquinolines were afforded in good to excellent yields in a direct, facile, and efficient approach by Se‐catalyzed isocyanide insertion with 2‐vinylanilines under an air atmosphere. This reaction not only used low toxicity Se as the catalyst, isocyanobenzene substrates were compatible too compared to previous report. Meanwhile, an intramolecular cyclization of 2‐vinylanilines was developed to give 3‐aryl‐1H‐indoles in moderate to good yields by using SeO2as oxidant. Se/SeO2‐promoted approachfor a direct and efficient synthesis of 2‐aminoquinoline/3‐aryl‐1H‐indole derivatives has been reported that proceeds through intermolecular/self‐intramolecular cyclization reaction of 2‐vinylanilines.

This paper describes the case of a cross study between the C–N bond cleavage reaction field and the Catellani–Lautens reaction system. A series of highly functionalized C4-substituted indoles were synthesized using this strategy. By screening the alkyl groups of amines, the energy barrier of C–N bond cleavage reaction was reduced and the corresponding allenization products were avoided. Finally, the density functional theory calculation shows that the inert C–N bond activation reaction is not a concerted process; on the contrary, the coupling reaction first generates indole quaternary ammonium salt, and then C–N bond cleavage occurs via an SN2 process.

A AgSCF3/Na2S2O8-promoted trifluoromethylthiolation/cascade cyclization of o-propargyl arylazides (or o-alkynyl benzylazides) triggered by a carbon–carbon triple bond is reported. This strategy provides the synthesis of valuable SCF3-substituted quinoline and isoquinoline systems via the construction of one C(sp2)–SCF3bond and one C–N bond within one process.

An efficient and general method for Pd-catalyzed dehydrogenative aromatization of dihydro-heteroatom compounds without external O2and H2is first described. The protocol firstly uses isoprene as a hydrogen acceptor. Various dihydro-heterocycles including dihydropyrimidinones, dihydropyrimidines and dihydropyridines can be dehydrogenated to produce the corresponding aromatic heterocyclic compounds.

This report describes the use of a simple Pd/NBE catalytic system to achieve orthoC–H oxylation and phosphonylation and other functionalizations of aryl iodide through templated conversion reactions. Dimethylamine is introduced in the ortho-site of aryl iodide through C–H amination, and aryl dimethylamine is quickly converted to methyl quaternary ammonium salt precipitation. Methyl quaternary ammonium salt avoids Hofmann elimination in subsequent functionalization. This method solves various orthofunctionalization reactions of aryl iodide that have not been achieved for a long time in the field of Pd/NBE chemistry indirectly.

A novel and efficient method for the catalytic installation of a carbonyl group via remote radical coupling is disclosed. The nickel-catalyzed reaction proceeds to undergo a sequential single-electron transfer, 1,5-hydrogen atom transfer, and carbonyl insertion, thus providing the α-substituted ketone. Further, this reaction could be carried out smoothly under normal pressure and redox-neutral conditions, and demonstrated functional-group compatibility and excellent site-selectivity.

Carbazole, as one of the most important organic frameworks, has been used in optoelectronic materials and biochemistry. However, the synthesis of C4-substituted carbazole has always been an unsolved problem. This report describes the one-step synthesis of C4-aminated carbazoles and their derivatives through the series reaction of C–H amination and arylation. The substrate scope is wide. C4-Amino carbazoles substituted by C2, C6, C7, and C8 methyl groups, especially carbazole derivatives of fused rings, pyridine, and dibenzofuran, can be synthesized.

A catalytic synthesis of N-benzothiazol-2-yl-amides from 1-acyl-3-(phenyl)thioureas was achieved in the presence of a palladium catalyst through the C(sp2)H functionalization/CS bond formation.

A reliable method for preparing P(III)‐arylphosphinecarboxamide derivatives from N‐arylphosphinecarboxamides and aryne precursors has been developed. This reaction was carried out without transition‐metal catalysts, and a series of unsymmetrically structured phosphinecarboxamide derivatives were obtained under mild conditions. In addition, the reaction is carried out under air atomosphere, and the corresponding P(III)‐aryl phosphinecarboxamide compounds are also stable in air. Metal‐free‐catalyzedP‐arylation with novel primary or secondary phosphines was developed. This transformation undergoes an addition of the P‐H bond into the aryne that was generated by fluoride anion‐induced activation of 2‐trimethylsilylaryl triflate to produce the corresponding P‐arylated product.

A metal-free synthesis of pyrimidine functionalized primary amines viadirect amination of pyrimidin-2-yl tosylates with aqueous ammonia under mild conditions was developed.

Polymer bound sulfonic acid (PEG-OSO3H) is active for the dehydration of biomass to furfural. The furfural yield is improved when MnCl2is added to the reaction mixture. The catalyst was mild, non-volatile, and non-corrosive and can be recycled multiple times (>10) without an intermediate regeneration step and no significant leaching of –OSO3H groups is observed.

A halotrimethylsilane (TMSX) accelerated cascade halophosphorylation and cycloisomerization of γ-hydroxyl ynones with diphenylphosphine oxides is presented. This methodology allows the one-step synthesis of practical polysubstituted halophosphorylated dihydrofuran derivatives. It is noteworthy that halotrimethylsilane functions as a halogenation reagent as well as a promoter to initiate this transformation. In addition, the reaction system can also be scaled up to gram quantities, and the produced halogenated compounds can undergo further derivatizations by Pd-catalyzed coupling reactions.

Sulfuric acid-modified polyethylene glycol 6000 (PEG-OSO3H) was applied as an efficient and recyclable catalyst for the synthesis of β-amino carbonyl compounds viathe Mannich reaction between aldehydes, aromatic ketones and aromatic amines at room temperature using PEG400–H2O (1:1) as environment-friendly solvents. The reactions were completed in short times and mild reaction conditions with good to excellent yields.

Using rare earth nitrates, tryptophan (L), and sodium citrate (NaL′), three new rare earth ternary complexes (Nd-L-L′· 4H2O, Eu-L-L′ · 4H2O, and La-L-L′ · 4H2O) were prepared. The complexes were characterized by IR, molar conductivity, TG-DTA (thermo gravimetric-differential thermal analysis), 1H NMR, and elemental analyses. TG and elemental analyses of the prepared complexes showed good agreement with their stoichiometry. Compared with two individual ligands, IR spectra of synthesized complexes showed dramatic shift and intensity changes; 1H NMR also showed a slight downfield shift. All analytical results of complexes proved constant composition of M-L-L′ · 4H2O (M = rare earth metal, namely Nd, Eu, or La). Animal tests were also performed to study the anti-coagulation time of these complexes considering also the different concentration of complex Nd-L-L′ · 4H2O. PC-12 pheochromocytoma cells were used to study cell adhesion. Compared with ions of rare earth compounds, rare earth ternary complexes have lower cell toxicity, better cell adhesion, and better anticoagulant action.

Cross double Mannich reaction and tandem cyclization were achieved under iodine catalyzed conditions, yielding a series of highly substituted 4-piperidones. Among the possible diastereomers, only one diastereomer was isolated, which could be ascribed to the chair-like transition state in six-membered ring, in which all of the hindered groups are located in the pseudoequatorial orientation.

A domino reaction of anilines with cyclic and acyclic enol ethers induced by catalytic amounts of TBPA+(5mol%) was investigated and a series of 2,4-disubstituted-1,2,3,4-tetrahydroquinolines were synthesized. Different from cyclic enol ethers, when acyclic enol ethers were used in the reaction, they serve as surrogates of acetaldehyde, producing a series of 2-methyl-4-anilino-1,2,3,4-tetrahydroquinolines. A single electron transfer mechanism was proposed to rationalize the products formation.

3,4-Dihydropyrimidinones modified with N3-(acetoxymethyl) and (aroyloxymethyl) groups can be regioselectively obtained in good yields by reactions of 3,4-dihydropyrimidinones with paraformaldehyde and substituted benzoic acids/acetic acid, by a one-pot two-step strategy in the presence of chlorotrimethylsilane. The advantages of this method are the simple procedure, the high regioselectivity of the products, shorter reaction time and the mild reaction conditions. Additionally, this method directly uses acid as acylation reagents and needs not acid anhydride or acyl chloride.

An I2‐induced double Mannich reaction and tandem cyclization of imines and ketones was investigated for the synthesis of a series of 1,2,6‐triaryl‐4‐piperidones. During the process of cyclization, only one product was produced out of four possible 4‐piperidones. Two pathways involving the balance between chelation effects and hydrogen bonding were proposed to rationalize the formation of the products, which was supported by further investigation of the reaction between β‐aminoketones and imines.

A double Mannich reaction followed by tandem cyclization of imines and ketones catalyzed by indium(III) chloride tetrahydrate (InCl3⋅4 H2O) was investigated, and a series of 1,2,6‐triaryl‐4‐piperidones was synthesized in a stereoselective way. In this reaction, aromatic imines substituted by electron‐withdrawing groups exhibited high reactivity toward the cyclization to 4‐piperidones. A variety of ketones are tolerated in this tandem process, including those that are sterically encumbered.

An environmental benign procedure for synthesis of 2-(N-formyl)-5-aryl/aryloxymethyl-1,3,4-thiadiazoles has been developed by reaction of 2-amino-5-aryl/aryloxymethyl-1,3,4-thiadiazoles with formic acid in PEG-400. The key advantages of this protocol are the shorter reaction time, higher yields, lower cost, simple workup, and environment-friendly compared to conventional organic solvent reaction. The present method does not involve any hazardous organic solvent or catalyst.

Under mild conditions, conversion of a variety of ketoximes and aldoximes to their corresponding amides and nitriles proceeded in the presence of PEG-SO3H with high yields.

An efficient protocol for the one-pot multicomponent synthesis of various 2,4,5-triaryl-1H-imidazoles and 1,2,4,5-tetraaryl-1H-imidazoles using PEG-400 as reaction medium is described. This method has the advantages of good yields, less pollution and simple reaction conditions.

An efficient and convenient method for thiazolo[3,2-a]pyrimidines from cyclization reaction of dihydropyrimidine- thiones with α-bromoacetone in aqueous media is described.

The onepot twostep synthesis for acyliminothiazolines by treatment of N,Nsubstituted thioureas with αbromocarbonyl compounds under aqueous media was described. Compared to classical reaction in organic solvents, this method consistently has the advantages of short reaction time and being environmentally friendly.

The synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride in the present of PEG–SO3H as efficient catalyst is described. The catalyst can be recovered and reused eight times.

A practical and rapid procedure is reported for the synthesis of a variety of 2-aryloxymethylene-6-arylimidazo[2,1-b][1,3,4]thiadiazole 3a–m by condensation reaction of 2-amino-5-aryloxymethylene-1,3,4-thiadiazole 1a–g with ω-bromoacetophenone derivatives 2a–b in aqueous media under microwave irradiation and yielded a series of novel compounds. The procedure is simple and the yields are good to excellent.

Poly(ethylene glycol) (PEG) supported dichlorophosphate was efficiently used as a recoverable new dehydration reagent for rapid synthesis of 2-amino-5-substituted-1,3,4-thiadiazoles under microwave irradiation and solvent-free condition by reactions of thiosemicarbazide with aliphatic acids, benzoic acid, aryloxyacetic acids or furan-2-carboxylic acids.

The synthesis of 1,2,3-triazole derivatives on a modified soluble polymer, poly(ethylene glycol)(PEG), is described.

An efficient synthesis of substituted 1,2,4-triazoles has been extended, utilising a wide range of N-substituted amides and hydrazides