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1.
Environ Sci Technol ; 58(31): 13678-13686, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39047073

RESUMO

Benzalkonium chlorides (BACs) have been of environmental concern due to their widespread use and potential harm. However, challenges arise in defining and controlling the exposure concentration (Cw) in aquatic toxicity tests involving BACs with a long alkyl chain (i.e., #C > 14). To address this, a novel passive dosing method was introduced in the 48 h-acute ecotoxicity test on Daphnia magna and compared to the conventional solvent-spiking method in terms of Cw stability and toxicity results. Among 13 sorbent materials tested for their sorption capacity, poly(ether sulfone) (PES) membrane was an optimal passive dosing reservoir, with equilibrium desorption of BACs to water achieved within 24 h. The Cw of BACs remained constant in both applied dosing methods during the test period. However, the Cw in solvent-spiking tests was lower than the nominal concentration for long-chain BACs, particularly at low exposure concentrations. Notably, the solvent-spiking tests indicated that the toxicity of BACs increased with alkyl chain length from C6 to 14, followed by a decline in toxicity from C14 to 18. In contrast, the passive dosing method displayed similar or slightly increasing toxicity levels of BACs from C14 to C18, indicating higher toxicity of C16 and C18-BACs than that inferred by the solvent spiking test. These findings emphasize the potential of applying this innovative passive dosing approach in aquatic toxicity tests to generate reliable and accurate toxicity data and support a comprehensive risk assessment of cationic surfactants.


Assuntos
Compostos de Benzalcônio , Daphnia , Tensoativos , Poluentes Químicos da Água , Animais , Compostos de Benzalcônio/toxicidade , Tensoativos/toxicidade , Daphnia/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Testes de Toxicidade Aguda , Cátions
2.
Chemosphere ; 363: 142924, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39048046

RESUMO

With the advent of technological advancements post the industrial revolution, thousands of chemicals are introduced into the market annually to enhance different facets of human life. Among these, pharmaceutical and personal care products (PPCPs), including antibiotics and disinfectants, such as benzalkonium chlorides (BACs), are prominent. BACs, often used for surface and hand disinfection in high concentrations or as preservatives in health products such as nasal sprays and eye drops, may present environmental risks if they seep into irrigation water through prolonged exposure or improper application. The primary objective of this study is to elucidate the tolerance mechanisms that may arise in Lemna minor plants, known for their remarkable capability to accumulate substances efficiently, in response to exogenously applied BACs at varying concentrations. The study applied six different concentrations of BACs, ranging from 0.25 to 10 mg L-1. The experimental period spanned seven days, during which the treatments were conducted in triplicate to ensure reliability and reproducibility of the results. It was observed that low concentrations of BACs (0.25, 0.5 and 1 mg L-1) did not elicit any statistically significant changes in growth parameters. However, higher concentrations of BACs (2.5, 5, and 10 mg L-1) resulted in a reduction in RGR by 20%, 28%, and 36%, respectively. Chlorophyll fluorescence declined significantly at BAC doses of 5 and 10 mg L-1, with Fv/Fm ratios decreasing by 9% and 15%, and Fv/Fo ratios by 40% and 39%, respectively. Proline content decreased in all treatment groups, with a 46% reduction at 10 mg L-1 BAC. TBARS and H2O2 contents increased proportionally with BAC dosage, showing the highest increases of 30% and 40% at 10 mg L-1, respectively. The noticeable increase in SOD enzyme activity at BAC concentrations of 0.5, 1, and 2.5 mg L-1, with increases of 2.7-fold, 2.2-fold, and 1.7-fold respectively, along with minimal accumulation of H2O2, suggests that L. minor plants have a strong tolerance to BAC. This is supported by the efficient functioning of the CAT and GST enzymes, especially evident at the same concentrations, where increased activities effectively reduce the buildup of H2O2. In the AsA-GSH cycle, although variations were observed between groups, the contribution of the GR enzyme to the preservation of GSH content by recycling GSSG likely maintained redox homeostasis in the plant, especially at low concentrations of BACs. The study revealed that L. minor effectively accumulates BAC alongside its tolerance mechanisms and high antioxidant activity. These results underscore the potential for environmental cleanup efforts through phytoremediation.


Assuntos
Antioxidantes , Araceae , Compostos de Benzalcônio , Fotossíntese , Espécies Reativas de Oxigênio , Antioxidantes/metabolismo , Araceae/efeitos dos fármacos , Araceae/metabolismo , Compostos de Benzalcônio/toxicidade , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Poluentes Químicos da Água/toxicidade
3.
Chemistry ; : e202402293, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037002

RESUMO

A sustainable and scalable protocol for synthesizing variously functionalized sulfonamides, from amines and sulfonyl chlorides, has been developed using environmentally responsible and reusable choline chloride (ChCl)-based deep eutectic solvents (DESs). In ChCl/glycerol (1:2 mol mol-1) and ChCl/urea (1:2 mol mol-1), these reactions yield up to 97% under aerobic conditions at ambient temperature within 2-12 h. The practicality of the method is exemplified by the sustainable synthesis of an FFA4 agonist and a key building block en route to anti-Alzheimer drug BMS-299897. A subtle interplay of electronic effects and the solubility characteristics of the starting materials in the aforementioned DESs seem to be responsible for driving the reaction successfully over the hydrolysis of sulfonyl chlorides. The procedure's eco-friendliness is validated  by quantitative metrics like the E-factor and the EcoScale, with products isolated by extraction or filtration after decantation.

4.
Angew Chem Int Ed Engl ; : e202409336, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38923746

RESUMO

Birefringent crystals have essential applications in optical communication areas. Low-dimensional structures with inherited structural anisotropy are potential systems for investigating birefringent materials with large birefringence. In this work, the zero-dimensional (0D) [(p-C5H5NO)2ZnCl2] (1) and [p-C5H6NO]2[ZnCl4] (2) were obtained by introducing the π-conjugated p-C5H5NO (4HP) into the three-dimensional (3D) ZnCl2. Remarkably, 1 exhibits a giant birefringence of 0.482@546 nm, which is the largest among Zn-based ultraviolet (UV) compounds and 160 times that of ZnCl2. According to structural and theoretical calculation analyses, the large optical polarizability, high spatial density, ideal distribution of the [(4HP)2ZnCl2]0 cluster, and the low dimension of 1 result in the dramatically increased birefringence compared to ZnCl2. This work will provide a valid route for accelerating the design and synthesis of compounds with excellent birefringence in low-dimensional systems.

5.
J Colloid Interface Sci ; 674: 603-611, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38945027

RESUMO

Rechargeable magnesium battery is regarded as the promising candidate for the next generation of high-specific-energy storage systems. Nevertheless, issues related to severe Mg-Cl dissociation at the electrolyte-electrode interface impede the insertion of Mg2+ into most materials, leading to severe polarization and low utilization of Mg-storage electrodes. In this study, a metal-organic polymer (MOP) Ni-TABQ (Ni-coordinated tetramino-benzoquinone) with superior surface catalytic activity is proposed to achieve the high-capacity Mg-MOP battery. The layered Ni-TABQ cathode, featuring a unique 2D π-d linear conjugated structure, effectively reduces the dissociation energy of MgxCly clusters at the Janus interface, thereby facilitating Mg2+ insertion. Due to the high utilization of active sites, Ni-TABQ achieves high capacities of 410 mAh/g at 200 mA g-1, attributable to a four-electron redox process involving two redox centers, benzoid carbonyls, and imines. This research highlights the importance of surface electrochemical processes in rechargeable magnesium batteries and paves the way for future development in multivalent metal-ion batteries.

6.
Chemistry ; 30(47): e202401591, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-38844428

RESUMO

The Ni-catalyzed enantioselective addition reaction of aryl halides to aldehydes was studied with cyanobis(oxazoline) as chiral ligands and Mn as reductant. Aryl and heteroaryl bromides reacted with phenyl aldehyde at room temperature to produce dibenzyl alcohols in 16-99 % yields with 53-92 % ees. Moreover, the coupling of phenyl chloride with a variety of aryl, heteroaryl and alkyl aldehydes was demonstrated in the presence of cyanobis(oxazoline)/Ni(II) at 60 °C in generally high yields with moderate enantioselectivities.

7.
Molecules ; 29(12)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38930928

RESUMO

A mild, efficient and practical protocol for the preparation of 2-sulfonylquinolines through CS2/Et2NH-induced deoxygenative C2-H sulfonylation of quinoline N-oxides with readily available RSO2Cl was developed. The reaction proceeded well under transition-metal-free conditions and exhibited a wide substrate scope and functional group tolerance. The preliminary studies suggested that the nucleophilic sulfonyl sources were generated in situ via the reaction of CS2, Et2NH and sulfonyl chlorides.

8.
Angew Chem Int Ed Engl ; : e202408974, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837734

RESUMO

Palladium-catalyzed cross-couplings of aryl chlorides usually call for bulky, electron-rich ligands such as phosphines or heterocyclic carbenes. We have now found that similarly powerful cross-coupling catalysts are obtained by the reaction of palladium salts with alkynyllithium reagents. The species initially formed in this process was characterized as a dilithium tetraalkinyl palladate complex. It catalyzes the coupling of aryl chlorides with the lithium salts of various terminal alkynes to give alkynyl arenes. The isolated Li-alkynyl-Pd complex also efficiently promotes the reaction of aryl, and allyl chlorides with (hetero)aryl-, alkyl-, and allyllithium compounds as well as lithium amides. None of these reactions proceeded in the presence of palladium salts alone. The preparative utility of this approach was demonstrated by the synthesis of 49 molecules, including pharmaceutically relevant compounds.

9.
ACS Appl Mater Interfaces ; 16(22): 28771-28779, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38795117

RESUMO

Blue perovskite light-emitting diodes (LEDs) have emerged as promising candidates for full-color display and lighting applications. However, the fabrication of blue-emitting perovskite films typically requires an inert environment, leading to increased complexity and cost in the manufacturing process, which is undesirable for applications of perovskite LEDs. Herein, we report a strategy to fabricate bright blue-emitting perovskite films in ambient air by incorporating phosphonic chlorides in a perovskite precursor solution. We used two different phosphonic chlorides, diphenylphosphonic chloride (DPPC) and phenylphosphonic dichloride (PPDC), and comparatively studied their effects on the properties of perovskite films and the blue LEDs. It is found that PPDC possesses a stronger chlorination ability due to higher hydrolysis reactivity; meanwhile, it has a stronger interaction with the perovskite compared to DPPC, resulting in an improved film quality and enhanced blue emission with a photoluminescence quantum yield of 45%, which represents the record value for the air-processed blue perovskite films. Blue perovskite LEDs are fabricated, and the emission wavelengths are effectively tuned by controlling the concentration of phosphonic chlorides. Benefiting from the optimized perovskite films with reduced nonradiative recombination and promoted charge injection and transport, the PPDC-derived blue perovskite LEDs exhibit improved performance with an external quantum efficiency of 3.3% and 1.2% for the 490 and 480 nm emission wavelength, respectively.

10.
Materials (Basel) ; 17(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38730766

RESUMO

With the rapid development of high and new technology, rubidium and its compounds show broad application prospect and market demand with their unique characteristics. At present, the production of rubidium metal is mainly prepared by calcium thermal reduction of rubidium chloride. Rubidium metal obtained by reduction requires multi-step vacuum distillation to obtain high-purity rubidium metal. The purity of rubidium metal depends on the purity of the raw material rubidium chloride. Rubidium metal is relatively active and is easy to oxidize and explode in air. Therefore, a method combining vacuum decomposition and vacuum distillation to reduce impurity elements in rubidium chloride from raw materials is proposed in this paper. The experimental results show that under the conditions of pressure of 5-10 Pa, distillation temperature of 823 K and vacuum distillation time of 60 min, the contents of Si and Zn impurities are reduced from 1206 mg/kg and 310 mg/kg to less than 0.1 mg/kg, and the removal rates are 99.99% and 99.97%, respectively. Rubidium chloride has almost no loss, and through one-step vacuum distillation, the impurity elements silicon and zinc can be deeply removed, reducing the flammability and explosiveness, high cost, long process and other problems caused by the subsequent preparation of high-purity rubidium metal.

11.
Chem Biodivers ; 21(8): e202400825, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38802323

RESUMO

Herein, we report analogues of s-indacene by the synthesis of novel indolizine derivatives. Using chloroform as an appropriate solvent, sixteen derivatives of pyrazolyl-indolizine (4--19) were prepared by the reaction of 3-(dimethylamino)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (1) with hydrazonoyl chloride derivatives (2) in the presence of triethylamine in good to excellent yields. We used NMR spectra, IR, mass spectrometry, as well as elemental analyses to prove the chemical structures and the purity of the synthesized compounds 4-19. Among all tested compounds 5, 9, 13 and 19 had a potent antimicrobial efficiency against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aerginousea, Sallmonella typhemerium, and Candida albicans. Furthermore, a significant increase in lipid peroxidation (LPO) toward the Gram-negative bacteria, Pseudomonas aeruginosa when treated with compound 9 was observed, while compound 13 remarkably increased the cell membrane oxidation of Salmonella typhimurium. Additionally, we utilized docking studies and in silico methods to evaluate the drug-likeness, physicochemical properties, and ADMET profiles of the compounds. The results of the molecular docking simulation revealed that the synthesized compounds displayed decreased binding energy when interacting with the active sites of important enzymes, including Sterol 14-demethylase of C. albicans, Dihydropteroate synthase of S. aureus, LasR of P. aeruginosa, Glucosamine-6-phosphate synthase of S. typhimurium, and Gyrase B of B. subtilis.


Assuntos
Candida albicans , Indolizinas , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Candida albicans/efeitos dos fármacos , Indolizinas/química , Indolizinas/farmacologia , Indolizinas/síntese química , Indolizinas/metabolismo , Pirazóis/química , Pirazóis/farmacologia , Pirazóis/síntese química , Pirazóis/metabolismo , Antibacterianos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Relação Estrutura-Atividade , Estrutura Molecular , Anti-Infecciosos/farmacologia , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Bactérias/efeitos dos fármacos
12.
Materials (Basel) ; 17(7)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38612130

RESUMO

AISI 304L stainless steel is widely used in the processing equipment and food and beverage handling industries due to its corrosion resistance, hygienic properties, and cost-effectiveness. However, it is prone to pitting and crevice corrosion phenomena, the development of which can be influenced by factors such as chloride concentration, temperature, humidity, and bacterial presence. Surface treatments, including roughness levels and residual tensile stress, can significantly affect the corrosion behavior and resistance of the material. This study aims to evaluate the impact of three different surface treatments on the durability of AISI 304L steel. The correlation between surface roughness resulting from pre-treatment and pitting potential values will be examined. Additionally, the influence of different concentrations of biocide additives on surface durability will be assessed to determine the maximum effective concentration for preventing pitting phenomena. Passivation processes will also be evaluated as a potential solution for improving the pitting potential and overall durability of the components. By optimizing surface treatments and biocide concentrations, improved corrosion resistance and durability can be achieved, ensuring the long-term performance and reliability of AISI 304L steel components in critical applications such as food processing and beverage handling.

13.
Beilstein J Org Chem ; 20: 787-814, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38655559

RESUMO

The hydrochlorination of alkenes has been extensively studied in research and is commonly featured in organic chemistry textbooks as an exemplification of the Markovnikov rule. However, the application of this reaction is typically limited to specific alkenes, such as highly substituted ones, styrenes, or strained systems. Conversely, monosubstituted or 1,2-disubstituted alkenes do not readily react with HCl gas or solutions of HCl gas at practical rates. The challenges associated with hydrochlorination reactions for these "non-activated" alkenes have spurred considerable research efforts over the past 30 years, which constitute the primary focus of this review. The discussion begins with classical polar hydrochlorinations, followed by metal-promoted radical hydrochlorinations, and concludes with a brief overview of recent anti-Markovnikov hydrochlorinations.

14.
Angew Chem Int Ed Engl ; 63(19): e202402849, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38389271

RESUMO

Functionalized primary alkyl chlorides are precursors to a plethora of scaffolds but their access from chemical feedstocks remains challenging. Herein, we report a concise dual Ni/photoredox catalytic protocol for regioselective chlorocarbonylation of unactivated alkenes that enables rapid access to ß-keto primary chlorides. The catalytic process features an extensive substrate scope, scalability and functional group tolerance. The Ni/photocatalytic Cl⋅ generation and subsequent cross-coupling is implicated for the process based on the control experiments and DFT study. The synthetic utility of the protocol has been further corroborated through functionalization of complex substrates and modifications of the product.

15.
Sci Total Environ ; 919: 170676, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38350567

RESUMO

As one of the most commonly used biocidal cationic surfactants, benzalkonium chlorides (BACs) have been an increasing concern as emerging contaminants. Wastewater has been claimed the main point for BACs to enter into the environment, but to date, it is still largely unknown how the BACs affect the microbes (especially microalgae) in the practical wastewater and how to cost-effectively remove them. In this study, the inhibitory effects of a typical BACs, dodecyl dimethyl benzyl ammonium chloride (DDBAC), on a green microalga Chlorella sp. in oxidation pond wastewater were investigated. The results showed that though a hermetic effect at the first 2 days was observed with the DDBAC at low concentration (<6 mg/L), the algal growth and photosynthesis were significantly inhibited by the DDBAC at all the tested concentrations (3 to 48 mg/L). Fortunately, a new microbial consortium (MC) capable of degrading DDBAC was screened through a gradient domestication method. The MC mainly composed of Wickerhamomyces sp., Purpureocillium sp., and Achromobacter sp., and its maximum removal efficiency and removal rate of DDBAC (48 mg/L) respectively reached 98.1 % and 46.32 mg/L/d. Interestingly, a microbial-microalgal system (MMS) was constructed using the MC and Chlorella sp., and a synergetic effect between the two kinds of microorganisms was proposed: microalga provided oxygen and extracellular polysaccharides as co-metabolic substrates to help the MC to degrade DDBAC, while the MC helped to eliminate the DDBAC-induced inhibition on the alga. Further, by observing the seven kinds of degradation products (mainly including CH5O3P, C6H5CH2-, and C8H11N), two possible chemical pathways of the DDBAC degradation were proposed. In addition, the metagenomic sequencing results showed that the main functional genes of the MMS included antibiotic-resistant genes, ABC transporter genes, quorum sensing genes, two-component regulatory system genes, etc. This study provided some theoretical and application findings for the cost-effective pollution prevention of BACs in wastewater.


Assuntos
Chlorella , Microalgas , Águas Residuárias , Cloreto de Amônio/metabolismo , Consórcios Microbianos , Chlorella/metabolismo , Técnicas de Cocultura , Biomassa
16.
Rev. SOBECC (Online) ; 29: E2429908, Fev. 2024. ilus
Artigo em Inglês, Português | LILACS | ID: biblio-1567245

RESUMO

Objetivo: Analizar la resistencia a la corrosión por picaduras de aceros inoxidables AISI 304 y AISI 420 en un medio que contiene cloruros (solu-ción de NaCl al 0,9 y 3,5%, en masa), así como su citotoxicidad, in vitro, en muestras con y sin corrosión por picaduras. Método: Estudio experimental. Se utilizaron técnicas de polarización potenciodinámica cíclica (PPC) para caracterizar el alcance y la forma del ataque corrosivo a las muestras. Se utilizó el método de difusión en agar y evaluación de la viabilidad de la línea celular NCTC clon 929 (CCIAL 020) para evaluar la citotoxicidad de las muestras de acero con y sin picaduras. Resultados: El acero AISI 304 presentó una resistencia a la corrosión superior al acero AISI 420. Los valores de potencial de picadura disminuyeron para ambos aceros cuando aumentó la concentración de cloruros en la solución agresiva. Hubo toxicidad celular moderada (grado 3 ­ ISO 10993-5) en todas las muestras. Conclusión: Los resultados corroboraron las recomendaciones para evitar la inmersión innecesaria de instrumentos en soluciones salinas. La citotoxicidad moderada de estos aceros desaconseja su uso en dispositivos implantables, reservándolos solo para instrumentos quirúrgicos. (AU)


Objective: To analyze the pitting corrosion resistance of AISI 304 and AISI 420 stainless steels in chloride-containing medium (0.9 and 3.5% NaCl solution, by weight), as well as their cytotoxicity,in vitro, in samples with and without pitting corrosion. Method: This is an experimental study. Cyclic potentiodynamic polarization (CPP) techniques were used to characterize the extent and shape of the corrosive attack on the samples. The agar diffusion and viability evaluation method of the NCTC clone 929 cell line (CCIAL 020) was used to evaluate the cytotoxicity of samples of steels with and without pitting. Results: The AISI 304 steel showed superior corrosion resistance to the AISI 420 steel. The values of the pitting potentials decreased for both steels when the chloride concentration in the aggressive solution was increased. There was moderate cell toxicity (grade 3 ­ ISO 10993-5) in all samples. Conclusions: The results corroborated the recommendations to avoid unnecessary immersion of the instruments in saline solutions. Moderate cytotoxicity to these steels contraindicates their use in implantable devices, only in surgical instruments. (AU)


Objetivo: Analisar a resistência à corrosão por pites dos aços inoxidáveis AISI 304 e AISI 420 em meio contendo cloretos (solução de NaCl a 0,9 e 3,5%, em massa), assim como sua citotoxicidade,in vitro, em amostras com e sem corrosão por pites. Método: Estudo experimental. Utilizaram-se téc-nicas de polarização potenciodinâmica cíclica (PPC) para caracterizar extensão e forma do ataque corrosivo nas amostras. O método de difusão em ágar e avaliação da viabilidade da linhagem celular NCTC clone 929 (CCIAL 020) foi empregado para avaliar a citotoxicidade de amostras dos aços com e sem pites. Resultados: O aço AISI 304 apresentou resistência à corrosão superior ao aço AISI 420. Os valores dos potenciais de pite caíram para ambos os aços quando se aumentou a concentração de cloretos na solução agressiva. Houve moderada toxicidade celular (grau 3 ­ ISO 10993-5) em todas as amostras. Conclusão: Os resultados corroboraram as recomendações para evitar a imersão desnecessária dos instrumentais em soluções salinas. A citotoxicidade moderada para esses aços contraindica seu uso em dispositivos implantáveis, apenas em instrumentos cirúrgicos. (AU)


Assuntos
Aço Inoxidável , Cloretos , Toxicidade , Corrosão
17.
Top Curr Chem (Cham) ; 382(1): 3, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38265533

RESUMO

Amination reactions play a pivotal role in synthetic organic chemistry, facilitating the generation of nitrogen-containing scaffolds with broad applications in drug synthesis, material production, polymer formation, and the generation of amino acids and peptides. Amination offers the potential to fine tune the properties of natural products and produce functional materials for various applications. Palladium N-heterocyclic carbene (Pd-NHC) emerges as an innovative and highly effective catalyst in this context. Under favorable reaction conditions, this robust and simple catalyst efficiently facilitates the synthesis of a diverse range of compounds with varying complexity and utility. Pd-NHC complexes exhibit significant σ-electron donating potential, enhancing the ease of the oxidative addition process in their mechanistic pathway. Their steric topography further contributes to a rapid reductive elimination. These complexes demonstrate remarkable stability, a result of the strong Pd-ligand bond. The wide variety of Pd-NHC complexes has proven highly efficient in catalyzing reactions across a spectrum of complexities, from simple to intricate. The domain of aminations catalyzed by Pd-NHC has undergone significant diversification, presenting new opportunities, particularly in the realms of material chemistry and natural product synthesis. This review outlines the advancements in Pd-NHC-catalyzed amination reactions, covering literature up to date.


Assuntos
Produtos Biológicos , Paládio , Aminação , Metano , Aminoácidos
18.
Angew Chem Int Ed Engl ; 63(6): e202314355, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-37914669

RESUMO

Cheap, stable and easy-to-handle Werner ammine salts have been known for more than a century; but they have been rarely used in organic synthesis. Herein, we report that the Werner hexammine complex [Ni(NH3 )6 ]Cl2 can be used as both a nitrogen and a catalytic nickel source that allow for the efficient amination of aryl chlorides in the presence of a catalytic amount of bipyridine ligand under the irradiation of 390-395 nm light without the need of any additional catalysts. More than 80 aryl chlorides, including more than 20 drug molecules, were aminated, demonstrating the practicality and generality of this method in synthetic chemistry. A slow NH3 release mechanism is in operation, obviating the problem of catalyst poisoning. Still interestingly, we show that the Werner salt can be easily recovered and reused, solving the problem of difficult recovery of transition metal nickel catalysts. The protocol thus provides an efficient new strategy for the synthesis of primary aryl amines.

19.
Angew Chem Int Ed Engl ; 63(1): e202313830, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-37963333

RESUMO

Reactions of unactivated alkyl chlorides under mild and sustainable conditions are rare compared to those of alkyl bromides or iodides. As a result, synthetic methods capable of modifying the vast chemical space of chloroalkane reagents, wastes, and materials are limited. We report the cobalt-catalyzed reductive addition of unactivated alkyl chlorides to conjugated alkenes. Co-catalyzed activation of alkyl chlorides is performed under electroreductive conditions, and the resulting reactions constitute formal alkyl-alkyl bond formation. In addition to developing an operationally simple methodology, detailed mechanistic studies provide insights into the elementary steps of a proposed catalytic cycle. In particular, we propose a switch in the mechanism of C-Cl bond activation from nucleophilic substitution to halogen atom abstraction, which is critical for efficiently generating alkyl radicals. These mechanistic insights were leveraged in designing ligands that enable couplings of primary, secondary, and tertiary alkyl chlorides.

20.
Adv Mater ; 36(4): e2310565, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37991721

RESUMO

Perovskite chloride, an anion conductor, is a promising candidate to be a solid electrolyte for high-energy and sustainable chloride ion batteries (CIB). However, it suffers from poor structural stability at low temperature and in ambient conditions, which leads to its transformation from an ionic conductor to an insulator. Herein, a bismuth and chlorine dual doping strategy is developed to stabilize the cubic structure of CsSnCl3 in harsh environments. The as-prepared dual-doped CsSn0.9 Bi0.1 Cl3.1 material with an optimized composition maintains its cubic structure at the extremely low temperature of 213 K for 10 days and at 40% relative humidity for 50 days, while the undoped cubic material deteriorates and transforms to a monoclinic phase under these conditions in less than 1 day. Consequently, the dual doping achieves efficient chloride ion conduction that is superior to single bismuth doping due to the introduction of interstitial chlorine facilitating chloride ion transport. Importantly, the practicality of the as-prepared solid electrolyte is demonstrated in different symmetric solid cells and by various CIBs using the organic electrode couple, a multivalent metal chloride cathode, or a new high-voltage metal oxychloride cathode.

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