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Aromatic amines are a large group of chemical compounds that have attracted the attention of researchers due to their toxicity and carcinogenicity. This study aimed to develop an efficient method for sampling and analysis of aromatic amines (Aniline, N, N-dimethylaniline, 2-chloroaniline, and 3-chloroaniline) from the vapour phase (headspace) of urine samples. For the implementation of this plan, a needle trap device packed with the three-component adsorbent consisting of nano-Hydroxy Apatite (nHA), Zeolite (Ze), and Metal–Organic Framework (MOF) equipped with GC-FID was employed for the first phase. Examination of the prepared adsorbents was performed by FT-IR, PXRD, and FE-SEM techniques. The optimal value of considerable parameters such as time and temperature of extraction, salt content, and pH were established using the Response Surface Methodology-Central Composite Design (RMS-CCD) method. In this way, the optimal extraction of targeted analytes was accomplished in 41 min at 41 °C with NaCl content of 33.0% (w/v) and pH: 13.0, respectively. Also, the repeatability and reproducibility of the method were calculated to be in the range of 2.2–7.1% and 3.9–8.1%, respectively, which indicates the acceptable precision of the method. Also, the limit of detection (LOD) and limit of quantification (LOQ) were determined in the range of 0.3–32.0 ng.L−1 and 0.8–350.0 ng.L−1, respectively, which proves the high sensitivity of the proposed method. Furthermore, the recovery percent of the extracted analytes was concluded in the range of 97.0–99.0% after 6 and 30 days of the sampling and storage at 25 °C and 4 °C, respectively. Finally, the designed procedure was employed in the analysis of the above-mentioned aromatic amines in the real urine samples. The achieved results illustrate that the three-component absorbent system (nHA;Ze;MOF@NTD) can be introduced as an efficient, fast-response, sensitive, and versatile procedure for trace analysis of the different aromatic amine compounds in public and occupational health. [ABSTRACT FROM AUTHOR]

Asymmetric functionalization of amines and their derivatives is of great significance in synthetic chemistry and is widely used in the preparation of natural products and pharmaceuticals. In recent years, chiral aldehyde catalysis has emerged as a well-established and recognized tool, providing excellent catalytic activation and stereoselective control in asymmetric reactions of N-unprotected amino acid esters and amino acid ester analogues. In this short review, recent advances in enantioselective aldehyde catalysis, including chiral aldehydes as organocatalysts and co-catalysis combined with transition metals, will be summarized. Lastly, continued development of enantioselective aldehyde catalysis is prospected in the future. 1 Introduction 2 Chiral Aldehyde Catalysis for Tethering Strategy 3 Chiral Aldehyde Catalysis for Imine Activation 4 Chiral Aldehyde/Transition Metal Cooperative Catalysis 5 Conclusion [ABSTRACT FROM AUTHOR]

The Knoevenagel reaction is a classic reaction in organic chemistry for the formation of C-C bonds. In this study, various catalytic monomers for Knoevenagel reactions were synthesized and polymerized via photolithography to form polymeric gel dots with a composition of 90% catalyst, 9% gelling agent and 1% crosslinker. Furthermore, these gel dots were inserted into a microfluidic reactor (MFR) and the conversion of the reaction using gel dots as catalysts in the MFR for 8 h at room temperature was studied. The gel dots containing primary amines showed a better conversion of about 83–90% with aliphatic aldehyde and 86–100% with aromatic aldehyde, compared to the tertiary amines (52–59% with aliphatic aldehyde and 77–93% with aromatic aldehydes) which resembles the reactivity of the amines. Moreover, the addition of polar solvent (water) in the reaction mixture and the swelling properties of the gel dots by altering the polymer backbone showed a significant enhancement in the conversion of the reaction, due to the increased accessibility of the catalytic sites in the polymeric network. These results suggested the primary-amine-based catalysts facilitate better conversion compared to tertiary amines and the reaction solvent had a significant influence on organocatalysis to improve the efficiency of MFR. [ABSTRACT FROM AUTHOR]

Steroids and their derivatives have been the subject of extensive research among investigators due to their wide range of pharmacological properties, in which steroidal oximes are included. Oximes are a chemical group with the general formula R1R2C=N−OH and they exist as colorless crystals and are poorly soluble in water. Oximes can be easily obtained through the condensation of aldehydes or ketones with various amine derivatives, making them a very interesting chemical group in medicinal chemistry for the design of drugs as potential treatments for several diseases. In this review, we will focus on the different biological activities displayed by steroidal oximes such as anticancer, anti-inflammatory, antibacterial, antifungal and antiviral, among others, as well as their respective mechanisms of action. An overview of the chemistry of oximes will also be reported, and several steroidal oximes that are in clinical trials or already used as drugs are described. An extensive literature search was performed on three main databases—PubMed, Web of Science, and Google Scholar. [ABSTRACT FROM AUTHOR]

In this work, the design and synthesis of a series of photochromic gemini diarylethene-based ionic liquids (GDILs) with different cationic motifs is reported. Several synthetic pathways were optimized for the formation of cationic GDILs with chloride as the counterion. The different cationic motifs were achieved through the N-alkylation of the photochromic organic core unit with different tertiary amines, including different aromatic amines such as imidazole derivatives and pyridinium, and other non-aromatic amines. These novel salts present surprising water solubility with unexplored photochromic features that broaden their known applications. The covalent attachment of the different side groups dictates their water solubility and differences upon photocyclization. The physicochemical properties of GDILs in aqueous and in imidazolium-based ionic liquid (IL) solutions were investigated. Upon irradiation with ultraviolet (UV) light, we have observed changes in the physico-chemical properties of distinct solutions containing these GDILs, at very low concentrations. More specifically, in aqueous solution, the overall conductivity increased with the time of UV photoirradiation. In contrast, in IL solution, these photoinducible changes are dependent on the type of ionic liquid used. These compounds can improve non-ionic and ionic liquids' solutions since we can change their properties, such as conductivity, viscosity or ionicity, only by UV photoirradiation. The electronic and conformational changes associated with these innovative stimuli GDILs may open new opportunities for their use as photoswitchable materials. [ABSTRACT FROM AUTHOR]

The asymmetric γ‐regioselective‐alkylation reaction which is catalyzed by a chiral tertiary amine ((DHQ)2PHAL) and takes advantage of isatin‐derived Morita‐Baylis‐Hillman carbonates and CF3‐contained ketoimines, delivered chiral α‐trifluoromethylamine derivatives and incorporated an oxindole motif in yields of 65–98%, diastereoselectivities (>20:1 in most cases) and enantioselectivities of 73–99%. The subsequent deprotection gave α‐ trifluoromethyl amines in a stereoselective manner. Furthermore, fused polycyclic frameworks can be furnished by subsequent derivatization of the product without eroding its stereoselectivity. [ABSTRACT FROM AUTHOR]

A concise review covering updated presence and role of 2-phenethylamines in medicinal chemistry is presented. Open-chain, flexible alicyclic amine derivatives of this motif are enumerated in key therapeutic targets, listing medicinal chemistry hits and appealing screening compounds. Latest reports in discovering new bioactive 2-phenethylamines by research groups are covered too. [ABSTRACT FROM AUTHOR]

The electrochemical oxidation of amines is an essential alternative to the conventional chemical transformation that provides critical routes for synthesising and modifying a wide range of chemically useful molecules, including pharmaceuticals and agrochemicals. As a result, the anodic reactivity of these compounds has been extensively researched over the past seven decades. However, the different mechanistic aspects of the electrochemical oxidation of amines have never been discussed from a comprehensive and general point of view. This review examines the oxidation mechanism of aliphatic amines, amides, aniline and aniline derivatives, carbamates, and lactams, either directly oxidised at different electrode surfaces or indirectly oxidised by a reversible redox molecule, in which the reactive form was generated in situ. The mechanisms are compared and simplified to understand all possible pathways for the oxidation of amines using only a few general mechanisms. Examples of the application of these oxidation reactions are also provided. [ABSTRACT FROM AUTHOR]

A catalysis‐based regioselective 1,4‐fluorofunctionalization of trifluoromethyl substituted 1,3‐dienes has been developed to access compact, highly functionalized products. The process allows E,Z‐mixed dienes to be processed to a single E‐alkene isomer, and leverages an inexpensive and operationally convenient I(I)/I(III) catalysis platform. The first example of catalytic 1,4‐difluorination is disclosed and subsequently evolved to enable 1,4‐hetero‐difunctionalization, which allows δ‐fluoro‐alcohol and amine derivatives to be forged in a single operation. The protocol is compatible with a variety of nucleophiles including fluoride, nitriles, carboxylic acids, alcohols and even water thereby allowing highly functionalized products, with a stereocenter bearing both C(sp3)−F and C(sp3)−CF3 groups, to be generated rapidly. Scalability (up to 3 mmol), and facile post‐reaction modifications are demonstrated to underscore the utility of the method in expanding organofluorine chemical space. [ABSTRACT FROM AUTHOR]

This study describes the enantioseparation of three chiral amines as naphthaldimine derivatives, using normal phase HPLC with amylose and cellulose tris(3,5‐dimethylphenylcarbamate) chiral stationary phases (CSPs). Three chiral amines were derivatized using three structurally similar naphthaldehyde derivatizing agents, and the enantioselectivity of the CSPs toward the derivatives was examined. The degree of enantioseparation and resolution was affected by the amylose or cellulose‐derived CSPs and aromatic moieties as well as a kind of chiral amine. Especially, efficient enantiomer separation was observed for 2‐hydroxynapthaldimine derivatives on cellulose‐derived CSPs. Molecular docking studies of three naphthaldimine derivatives of leucinol on cellulose tris(3,5‐dimethylphenylcarbamate) were performed to estimate the binding energies and conformations of the CSP–analyte complexes. The obtained binding energies were in good agreement with the experimentally determined enantioseparation and elution order. [ABSTRACT FROM AUTHOR]

Simultaneous inhibition of histone deacetylases (HDACs) and anaplastic lymphoma kinase (ALK) could enhance therapeutic activity against ALK addicted cancer cells. Herein, a new series of 2,4-pyrimidinedi- amine derivatives as ALK and HDACs dual inhibitors were designed, synthesised and evaluated. Compound 12a which possessed good inhibitory potency against ALKwt and HDAC1, exhibited stronger antiproliferative activity than Ceritinib on ALK positive cancer cell lines though inducing cell apoptosis and cell cycle arrest in vitro and in vivo. In addition, the mechanism is further verified by the down-regulation of p-ALK protein, and up-regulation of Acetylated histone 3 (Ac-H3) protein in cancer cells. These results suggested that 12a would be a potential candidate for the ALK addicted cancer treatment. [ABSTRACT FROM AUTHOR]

A series of new combretastatin A4 derivatives (6a-6c, 9a-12c) containing nitrogen atoms and nitrogen heterocycles were synthesized by condensation reaction, reduction reaction, hydrolysis reaction and Crutius rearrangement, and the structures were confirmed by 1H NMR, 13C NMR and Mass spectrum. The antitumor cytotoxicity of a series of newly synthesized compounds were evaluated in vitro toward the cell line of hepatoma cell with erianin as positive control. Amoung all the compound, 6b exhibit the most antitumor activity against HepG2 (Human hepatoellular carcinomas) cell line with the inhibition rate 93.85%, and the other compounds also showed moderate to potent antitumor activity. To understand the interaction of series with active binding site of receptor, docking study was performed with VEGFR-2 (Vascular Endothelial Growth Factor Receptor 2) kinase domain in complex with axitinib using Sybyl. The compound with the highest total score was 9c, reaching 8.92, which was higher than that of the positive control erianin This research highlights the therapeutic potential of novel VEGFR-2 inhibitors in treating cancers and provides a promising strategy for drug discovery. [ABSTRACT FROM AUTHOR]

An unprecedented, Brookhart's acid‐catalyzed temperature‐switchable regioselective divergent approach for N‐alkylation of arylamines and heterocyclic amines by utilising cyclopropylcarbinols is presented herein. The reaction offers N‐alkylated cyclopropyl derivatives and homoallyl amines by employing 2.5 mol% catalyst loading at different temperatures in excellent regioselectivity and yields. This method has shown to be relevant with a wide range of cyclopropylcarbinols, including aliphatic ones. Several control experiments and spectroscopic studies have been performed to gain insight into the reaction mechanism. Further, the synthetic utility of the protocol has also been described. [ABSTRACT FROM AUTHOR]

A series of novel pinanyl pyrimidine amine derivatives (1e~1n) and camphoryl pyrimidine amine derivatives (2b~2f) bearing bicyclic monoterpene moieties were designed and synthesized from natural and renewable nopinone and camphor. All chemical structures of target compounds were characterized by 1H NMR, 13C NMR and HRMS spectra analyses, and the antimicrobial activities were evaluated. The results indicated that most compounds showed considerable antibacterial and antifungal activities against Klebsiella pneumoniae, Streptococcus pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Methicillin-Resistant Staphylococcus aureus (MRSA), Bacillus cereus and Candida albicans. Among them, 1f showed potent antibacterial activity against all tested bacteria, 1i exhibited excellent inhibition against Streptococcus pneumoniae (1 μg/mL) and Escherichia coli (1 μg/mL), which was better than the control drug amikacin (2 μg/mL). As to antifungal activity against Candida albicans (C. albicans), compound 1l showed comparable activity (16 μg/mL) to the control drug ketoconazole. Furthermore, five active compounds with better antimicrobial activities also showed anti-inflammatory potencies against mouse mononuclear macrophages leukemia cells (RAW). Especially, 1f (IC50 = 1.37 μM) and 2f (IC50 = 1.87μM) are more potent than the control drug aspirin (IC50 = 1.91 μM). [ABSTRACT FROM AUTHOR]

Boroaminomethylation of olefins is an efficient process to convert hydrocarbons directly into boron‐, nitrogen‐containing molecules. Such chemicals are a good handle for obtaining more complexed amine derivatives through the various transformations of organoboron. However, using simple and easily available CO as the C1 feedstock to achieve boroaminomethylation is still elusive. Here we report a copper‐catalyzed boroaminomethylation of olefins with CO as the C1 source via the mechanism of a carbene insertion into the N−H bond. This method affords valuable γ‐boryl amines from four inexpensive readily chemicals. The wide synthetic transformations of the γ‐boryl amines demonstrates their utility. Notably, 13C labeling studies revealed that the −CH2‐building block was derived from one molecule of CO. [ABSTRACT FROM AUTHOR]

The purpose of the present study aims to develop a satisfactory model for predicting pro-social and pro-cognitive effects on azinesulfonamides of cyclic amine derivatives as potential antipsychotics. The three dimensional-quantitative structure affinity relationship (3D-QSAR) study was performed on a series of azinesulfonamides of cyclic amine derivative using comparative molecular similarity indices analysis (CoMSIA). The best statistical model of CoMSIA q2, r2, SEE and F values are 0.664, 0.973, 0.087, and 82.344, respectively. Based on the model contour maps and the highest activity structure of the 43rd compound, serial new structures were designed and the 43k1 compound was selected as the best structure. The dock results showed a good binding of 43k1 with the protein (PDB ID: 6A93). The QSAR model analysis of the contour maps can help us to provide guidelines for finding novel potential antipsychotics. [ABSTRACT FROM AUTHOR]

Heat treatment of meat can lead to the formation of carcinogenic organic compounds. The influence of dried fruits on the formation of non-polar heterocyclic aromatic amines (carbolines) and nitrogen derivatives of polycyclic aromatic hydrocarbons (azaarenes) in roasted pork loin was elucidated. Two hundred grams of fruit per 1 kg of meat were used as stuffing. Carbolines, derivatives of pyridoimidazole and pyridoindole, and azaarenes (benzoacridines and dibenzoacridines) were determined by means of high-performance liquid chromatography with fluorescence detection. The total concentration of six δ-, γ- and α-carbolines in roasted pork loin was 1.3 ng/g. This content decreased by 64%, 58%, and 54% in pork loin stuffed with prunes, apricots, and cranberries, respectively. Concentrations of β-carbolines (harmane and norharmane) increased under the influence of added fruits. The norharmane content increased the most, from 2.2 ng/g in the control sample to 12.3 ng/g in meat prepared with cranberries. The harmane content increased from 1.0 ng/g to 3.6 ng/g in meat with prunes. The total concentration of azaarenes (two benzoacridines and dibenzo[a,c]acridine), which was close to 0.1 ng/g, decreased in dishes with prunes and apricots by 54% and 12%, respectively. Azaarenes were not found in samples of meat stuffed with cranberries. [ABSTRACT FROM AUTHOR]

• The biogenic amine derivative Schiff bases solid-state structure and geometry was determined. • The cytotoxic activities of these compounds against lung cancer and normal lung cells were determined. • mRNA xpression levels of cell death, cell cycle, and ER stress related genes were determined. • ER stress, apoptosis, and related signaling proteins were determined. • Necrosis, early and late apoptosis, and cell cycles were determined. Cancer continues to be a global health problem, and this problem requires the development of targeted anticancer agents. Syntheses of different derivatives of Schiff bases have attracted serious attention in cancer research due to the potential of this group of compounds as anticancer agents. For this purpose, the biogenic amine derivative Schiff bases (Schf 1–3) were synthesised. The solid-state structure and geometry of Schf-2 and Schf-3 were determined using single crystal X-ray structural analysis for the first time in this study. The isolated compounds were characterised by NMR (1H and 13C) spectroscopy, mass analysis, and single crystal X-ray crystallography. The cytotoxic activities of these compounds against lung cancer and normal lung cells were determined by the WST-8 assay. In addition, mRNA expression levels of cell death, cell cycle, and ER stress related genes were determined by qPCR. Besides, ER stress, apoptosis, and related signaling proteins were determined by ELISA. Moreover, necrosis, early and late apoptosis, and cell cycle were determined by Flow cytometry. The most effective % viability activity is Schf-1 , and IC50 value are 60.22% (27.73 μM) (LogIC50:1.443) in A549 cells. All compounds increased in MAPK gene expressions, also, gene expressions of HSP27, HSP40, HSP60, HSP70, HSP90 and AKT decreased by these compounds in A549 cells. Moreover, GRP78, Caspase-3, p-AKT, and MAPK protein levels were upregulated by these compounds. Furthermore, cell cycle, necrosis, and apoptosis are regulated by these molecules. Our findings indicate that these compounds have potential properties that suppress HSP genes and activate ER stress related apoptotic cell death and are notable for drug-improving studies. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis of hexafluorovaline-containing peptides. • The synthetic pathway foresees only four synthetic steps. • The reactions take place in mild condition. • The synthetic sequence is suitable for combinatorial purposes. A new strategy for the synthesis of peptides incorporating racemic hexafluorovaline (hfVal) is presented. The synthetic pathway relies on the anti-Michael addition of benzyl amine derivatives to ad hoc prepared β-bis-trifluoromethyl-acryloyl-α-amino esters which proceeds in mild condition, high yields, even if with low stereocontrol. The following elaboration of the intermediates, namely deprotection of the benzyl moiety and coupling with α-amino esters allowed us to synthetize the targeted tripeptides in four overall synthetic steps, resulting in a synthetic pathway more favorable respect to those appeared in literature based on the synthesis and isolation of racemic Boc-hfVal-OH (eight synthetic steps). [Display omitted] [ABSTRACT FROM AUTHOR]

The synthesis, structure, and reactivity of vanadium pyridonate complexes are described. Vanadium(III) pyridonate complexes were accessed through protonolysis and reduction of a tetrakis(amido)vanadium(IV) starting material. Bis(pyridonate) vanadium(IV) precursors could be isolated depending on the amount of proteoligand added. The targeted vanadium(III) species tend to form dimers, but monomeric complexes can be achieved in the presence of neutral donors such as amines or pyridine derivatives or through the use of sterically demanding proligands. The reduction process is proposed to involve dimeric intermediates and be mediated by the amine released from protonolysis, thereby forming the corresponding imine as a byproduct. Isolated amine complexes of vanadium(III) are presented. In contrast, bis(amidate)vanadium(IV) complexes were not found to undergo a similar reduction. This work informs on design principles for the synthesis and application of new vanadium pyridonate catalysts for transformations involving dimerization and PCET for changes in oxidation state. [ABSTRACT FROM AUTHOR]

Visible light excitation of iodine(III)–BF3 complex enables the formation of carbocations from C(sp3)–H bonds. The complexes are generated catalytically from iodoarene, carboxylate ligand, the oxidizing agent Selectfluor, and the Lewis acid BF3. This modular catalytic system allows the formation of synthetically valuable amine derivatives without a metal- or photocatalyst. [ABSTRACT FROM AUTHOR]

Reported here is the first catalytic atroposelective electrophilic amination of indoles, which delivers functionalized atropochiral N‐sulfonyl‐3‐arylaminoindoles with excellent optical purity. This reaction was furnished by 1,6‐nucleophilic addition to p‐quinone diimines. Control experiments suggest an ionic mechanism that differs from the radical addition pathway commonly proposed for 1,6‐addition to quinones. The origin of 1,6‐addition selectivity was investigated through computational studies. Preliminary studies show that the obtained 3‐aminoindoles atropisomers exhibit anticancer activities. This method is valuable with respect to enlarging the toolbox for atropochiral amine derivatives. [ABSTRACT FROM AUTHOR]

The utility of 2‐diphenylphosphoryloxy‐1,3‐dienes for the construction of substituted six‐membered nitrogen heterocycles is presented. These dienes undergo boron trifluoride‐promoted aza‐Diels–Alder reactions when reacted with imines or related species formed in situ using aldehydes and amine derivatives. The stability of the dienes allows this three‐component reaction to be carried out with no special precautions to eliminate water or air. Thirty‐one examples of this process are presented. The usefulness of the enol phosphate functional group is highlighted in further reactions after the cycloaddition step to generate functionalized piperidenes or pyridines. [ABSTRACT FROM AUTHOR]

Isocyanides are common compounds in fine and bulk chemical syntheses. However, the direct addition of isocyanide to simple unactivated cyclopropene via transition metal catalysis is challenging. Most of the current approaches focus on 1,1-insertion of isocyanide to M-R or nucleophilc insertion. That is often complicated by the competitive homo-oligomerization reactivity occurring at room temperature, such as isocyanide 1,1-insertion by Ni(II). Here we show a (N-heterocyclic carbene)Ni(II) catalyst that enables cyclopropene-isocyanide [5 + 1] benzannulation. As shown in the broad substrate scope and a [trans-(N-heterocyclic carbene)Ni(isocyanide)Br2] crystal structure, the desired cross-reactivity is cooperatively controlled by the high reactivity of the cyclopropene, the sterically bulky N-heterocyclic carbene, and the strong coordination ability of the isocyanide. This direct addition strategy offers aromatic amine derivatives and complements the Dötz benzannulation and Semmelhack/Wulff 1,4-hydroquinone synthesis. Several sterically bulky, fused, and multi-substituted anilines and unsymmetric functionalized spiro-ring structures are prepared from those easily accessible starting materials expediently. The direct addition of isocyanides to cyclopropenes is challenging. Here, the authors report a catalytic cyclopropene-isocyanide [5 + 1] benzannulation catalyzed by an (N-heterocyclic carbene)Ni(II) complex; this method enables the preparation of fused and multi-substituted anilines and unsymmetrically functionalized spiro-ring structures. [ABSTRACT FROM AUTHOR]

In the present work, the fluorescence quenching of novel thiophene substituted1,3,4-oxadiazole derivative 2-(4-(4-vinylphenyl) phenyl)-5-(5-(4-vinylphenyl)thiophen-2-yl)-1,3,4-oxadiazole (TSO) by five different environmental pollutant aromatic amine derivatives like 2,4-dimethylaniline, 3-chloroaniline, 4-chloroaniline, o-anisidine, and m-toluidine has been studied at room temperature through steady-state and time-resolved methods. It is observed that, the quenching efficiency is highest in the case of o-anisidine and least in the case of 3-chloroaniline. The fluorescence quenching mechanism between TSO and aromatic amines is analysed through different quenching models. The results suggest that, the fluorescence quenching is due to diffusion assisted dynamic or collisional quenching according to the sphere of action static quenching model and according to the finite sink approximation model, the bimolecular quenching reactions are due to the collective effect of dynamic and static quenching. Further, cyclic voltammetry and DFT studies suggest that the fluorescence quenching is due to electron transfer. Binding equilibria analysis confirms the 1:1 stoichiometric ratio between fluorophore and the quencher. [ABSTRACT FROM AUTHOR]

Functionalization of metal–organic framework (MOF) with various organic molecules to reinforce its surface potential in adsorption and stabilization of transition metal nanoparticles (NPs) is of great attention in creating/supporting ions metal within their framework and converting them into efficient heterogeneous catalysts. Here, we used a hybrid of inorganic–organic MOF (TMU‐16‐NH2) as an unparalleled compound for designing an efficient catalyst with nanoarchitecture via covalent functionalization of urea and 1,3‐propane sultone ligands. This hybrid nanoporous MOF was further engaged as a support in the synthesis and stabilization of Cu NPs on its surface, and then, the obtained Cu‐supported MOF was applied as a heterogeneous catalyst in the synthesis of propargyl amines derivatives under green reaction conditions with efficient recyclability. [ABSTRACT FROM AUTHOR]

The requirements for the fuel economy of modern industry continue to drive the progress of low-viscosity lubricants. The present work reports the application of polyether amine derivatives as friction modifiers to improve the tribological properties of low viscosity poly-alpha-olefin. Three polyether amine derivatives with different molecular weights were synthesized, the tribological properties of which were systematically investigated under three different contact modes. These functionalized polymers exhibited significant friction reduction and wear resistance properties in the point-on-flat and line-on-flat friction tests, but just showed anti-wear performance in the severe point-to-point contact mode. The results exhibited that molecular weights of the polymers had a direct effect on their tribological properties. The increase of molecular weight in a certain range was beneficial to the improvement of tribological properties, but further undue increase will rather reduce the friction reduction and wear resistance performances. It can be indicated that the number of oxygen atoms increased with the molecular weight of the polymer, which will be conductive to the adsorption of the polymer on the metal surface. However, when the molecular weight of the polymer exceeds a certain value, the steric hindrance of the molecules adsorbing to the metal surface increases, which in turn has a negative impact on the tribological properties. [ABSTRACT FROM AUTHOR]

A convenient synthetic protocol to antiviral agent B‐220 and a series of similar indolo[2,3‐b]quinoxaline derivatives has been developed. This synthetic approach is based on Buchwald‐Hartwig cross‐coupling and subsequent annulation by intramolecular oxidative cyclodehydrogenation. For the first time, 6H‐indolo[2,3‐b]quinoxaline amine derivatives were evaluated for antimycobacterial activity. The moderate bacteriostatic effect against Mycobacterium tuberculosis H37Rv was found. A plausible mechanism of antibacterial action was elucidated by the molecular docking. [ABSTRACT FROM AUTHOR]

• Thermal polymerization of melamine. • Fabrication of g-C 3 N 4 based photoactive photocatalyst. • Synthesis of selectively synthesized pharmaceutical materials. • Oxidative coupling of aryl amines. Oxidative coupling of amine derivatives to selectively synthesize pharmaceutical materials has been realized via photocatalysis. Herein we report on the fabrication and development of a graphitic carbon nitride (G) based visible light active photocatalyst (G-PTD), which is melamine converted graphitic carbon nitride(G) covalently integrated to a light harvesting perylene tetracarboxylic dianhydride (PTD) molecule. The synthesized photocatalyst has various functions in a highly active manner leading to high yield of newly generated azoaromatic compound. The current research endeavour highlights on the fabrication and utilization of a graphitic carbon nitride based photocatalyst for direct oxidative coupling of arylamines. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile strategy is proposed to construct 1T/2H mixed-phase MoS 2 induced via bacteria-derived carbon for pseudocapacitors. • The interlayer spacing of MoS 2 is enlarged by inserted amino acid derivatives to form the stable 1T-MoS 2. • The defect sites in the mixed-phase MoS 2 introduced by bacteria boost the K+ adsorption. • The 1T/2H MoS 2 anode shows a satisfactory lifespan of 110.2 % retention after 40,000 cycles. Pseudocapacitors (PCs) are considered prospective candidates for large-scale aqueous energy storage systems due to their high power density. However, the poor cycling stability resulting from sluggish metal ion transport kinetics and the instability of the electrode structure hinders their further applications. To address this issue, an effective strategy of 1T/2H mixed-phase MoS 2 directly grown on the electrochemically activated carbon (EC) induced via bacteria-derived carbon (BC) from bacillus subtilis is proposed to achieve efficient anodes for potassium ion capacitors. The inherent nitrogen elements found in the bacteria-derived carbon, along with a trace amount of amines and their derivatives generated from amino acid decarboxylation, act as support by inserting into the MoS 2 interlayer. Amines and their derivatives as intercalators could suppress the MoS 2 layer stacking and mitigate structure damage, which is responsible for preventing rapid capacity fading. Thus, the mixed-phase MoS 2 with an expanded interlayer spacing of 0.94 nm achieves a remarkable durability with a capacitance retention of 110.2 % after 40,000 cycles at 10 A g−1. Density Functional Theory (DFT) reveals that the mixed-phase MoS 2 could improve electron transfer ability and cyclic stability, in which the rich vacancies introduced by bacteria-derived carbon could enhance the K+ adsorption. To highlight, the asymmetric capacitor device (ASC) adopting mixed-phase MoS 2 anode shows a long lifespan (88 % capacitance retention over 10,000 cycles). This work will provide a green approach to boost cycling performance of MoS 2 anodes and shed light on developing high-performance MoS 2 -based materials for electrochemical energy storage. [ABSTRACT FROM AUTHOR]

Biobased materials are expanding dramatically in various industrial applications due to their unique intrinsic properties. In this study, various chemical functionalization procedures were used to synthesize guar gum, a naturally occurring polysaccharide-based polyurea, and its iodine complexes. Firstly, guar gum was subjected to tosylation reaction using p-toluene sulphonyl chloride to introduce tosyl moieties in the polymer chain with the degree of substitution (DS) ranging between 0.16 and 1.54. Sample having the highest degree of tosyl moiety was further reacted with tris(2-aminoethyl) amine to produce 6-deoxy-6-tris(2-aminoethyl) amine derivative via nucleophilic substitution reaction to impart amino functional groups. The degree of substitution in 6-deoxy-6-tris(2-aminoethyl) amine derivative was found to be 0.59. 6-deoxy-6-tris(2-aminoethyl) amine derivative was reacted with different diisocyanates (Toluene-2,4-diisocyanate (TDI), 1,6-diisocyanatohexane (HMDI)) to produce guar gum based polyurea. Iodine complexes of the resulting polyurea were prepared by reacting with different iodinating agents. Different chemical reactions, formation of polyurea and its iodine complexes were thoroughly analyzed by different analytical techniques such as FT-IR, NMR, elemental analysis, XRD, UV–Vis spectroscopy, and a reaction scheme has been proposed. Morphological and rheological characteristics were analyzed by SEM and viscosity measurement. Thermal analysis was carried out by TGA and DSC studies. Finally, by examining the complex's UV–Vis spectra, the iodine release characteristics from polyurea‑iodine complexes were investigated. [Display omitted] [ABSTRACT FROM AUTHOR]

Marine green algae produce sulfated polysaccharides with diverse structures and a wide range of biological activities. This study aimed to enhance the biotechnological potential of sulfated heterorhamnan (Gb1) from Gayralia brasiliensis by chemically modifying it for improved or new biological functions. Using controlled Smith Degradation (GBS) and O -alkylation with 3-chloropropylamine, we synthesized partially water-soluble amine derivatives. GBS modification increase sulfate groups (29.3 to 37.5 %) and α- l -rhamnose units (69.9 to 81.2 mol%), reducing xylose and glucose, compared to Gb1. The backbone featured predominantly 3- and 2-linked α- l -rhamnosyl and 2,3- linked α- l -rhamnosyl units as branching points. Infrared and NMR analyses confirmed the substitution of hydroxyl groups with aminoalkyl groups. The modified compounds, GBS-AHCs and GBS-AHK, exhibited altered anticoagulant properties. GBS-AHCs showed reduced effectiveness in the APTT assay, while GBS-AHK maintained a similar anticoagulant activity level to Gb1 and GBS. Increased nitrogen content and N -alkylation in GBS-AHCs compared to GBS-AHK may explain their structural differences. The chemical modification proposed did not enhance its anticoagulant activity, possibly due to the introduction of amino groups and a positive charge to the polymer. This characteristic presents new opportunities for investigating the potential of these polysaccharides in various biological applications, such as antimicrobial and antitumoral activities. • Chemical modification enhances sulfated heterorhamnan (Gb1)'s biotech potential. • Controlled Smith Degradation and O -alkylation led to water-soluble amine derivatives. • Increase in sulfate and α- l -rhamnose units were noted. • Aminated derivatives show varied anticoagulant effects. [ABSTRACT FROM AUTHOR]

It has of practical significance for environmental protection to find adsorbents with high efficiency, high adsorption capacity and high selectivity to treat radioactive uranium-containing wastewater. The metal–organic framework compound UiO-66-(OH)2 was synthesized by refluxing ZrCl4 and 2,5-dihydroxyterephthalic acid in N, N-dimethylformamide (DMF) at 80 ℃. UiO-66-(OH)2 was functionalized with hydroxylamine hydrochloride. UiO-66-(OH)2 amidoxime derivative obtained through chemical modification is used as adsorbent to adsorb U(VI). The result shows that the adsorption process of U(VI) on UiO-66-(OH)2 amidoxime derivative follows pseudo-second-order kinetics, the adsorption isotherm conforms to the Langmuir adsorption isotherm model. The material has good adsorption performance whose experimental results showed that the adsorption ratio of UiO-66-(OH)2 amidoxime derivative was 87.4% at C0 = 15 mg L−1, pH = 10.0 and T = 25 °C, indicating that the UiO-66-(OH)2 amidoxime derivative is a potential uranium adsorbent. [ABSTRACT FROM AUTHOR]

Two new approaches to the functionalization of the 1-carba-closo-decaborate anion [1-CB9H10]− at boron atoms via the ring-opening of its 1,4-dioxane derivative with various nucleophiles and Pd-catalysed cross-coupling of its iodo derivative with aromatic amines and heteroaromatics were developed. [ABSTRACT FROM AUTHOR]

Indium‐mediated allylation of N‐tert‐butanesulfinyl imines derived from indole‐2 and 3‐carbaldehydes 3 and 5 with allylic bromides 6, proceed with high diastereoselectivity. Homoallylic amide derivatives 13 and 14 are transformed into dihydropyridinones 15 and 16, upon successive desulfinylation, N‐acylation with acryloyl chloride and ring‐closing‐metathesis. Desulfinylation of amine ester derivatives 17 and 18, obtained when ethyl 2‐(bromomethyl)acrylate (6 b) is used as the allylating reagent, lead to the corresponding α‐methylene‐γ‐butyrolactams 19 and 20, in modest yields. [ABSTRACT FROM AUTHOR]

Protonated Ruddlesden-Popper phases HLnTiO 4 (Ln = La, Nd) have been used to yield two series of inorganic-organic derivatives containing non-covalently intercalated n -alkylamines and covalently grafted n -alkoxy groups with a various hydrocarbon chain length. Synthesis was carried out according to multistage schemes using both conventional benchtop and solvothermal methods. It was shown that inorganic-organic derivatives obtained contain approximately 0.4–0.5 interlayer organic molecules or groups per proton of the initial titanate as well as some amount of intercalated water. The introduction of organic components into the interlayer space of the titanates leads to its significant expansion and formation of a paraffin-like bilayer possessing an average tilting angle of 75.5°. At the same time, the organic modification does not result in noticeable changes in light absorption of the samples in near-ultraviolet and visible regions. Their thermal stability strongly depends on the nature of the organic component bonding. While non-covalent amine derivatives are stable only at low temperatures <50 °C, covalent alkoxy ones can withstand heating up to 250 °C without perceptible decomposition. While most of the products demonstrate good stability under reduced pressure, some of them undergo phase composition changes upon prolonged exposure to water. [ABSTRACT FROM AUTHOR]

Selective C−F bond functionalization of perfluoalkyl units has huge potential towards accessing functionalized organofluorinated compounds, but remains challenging due to the high C−F bond strength and inherent selectivity challenges. We report a new catalytic approach to the selective functionalization of strong C−F bonds in polyfluorinated aliphatic esters and amides. This simple reaction proceeds in mild and operational fashion with divergent conversions, including hydrodefluorination, defluoroalkylation, and defluoroalkenylation, affording a diverse array of important partially fluorinated motifs. Straightforward downstream chemistry towards fluorinated alcohols, amines and drug derivatives highlights the potential of the protocol. [ABSTRACT FROM AUTHOR]

The Diels–Alder reaction of N -benzylcytisine with N -methyl- and N -benzylmaleimides is 100% endo -selective and gives the corresponding syn - and anti -diastereomers in 11–42% isolated yields. The studies of the reaction progress with LCMS and NMR along with detailed quantum chemical calculations revealed that some Diels–Alder adducts are kinetically and their isomers are thermodynamically controlled products. The Pd/C-catalyzed hydrogenation of benzyl-protected cytisine amine derivatives resulted in the removal of the benzyl group and the addition of hydrogen to the C=C double bond to give the corresponding secondary amines in 45–84% yield. The complete reduction of carbonyl groups in a cytisine derivative with LiAlH4 in THF under reflux afforded the respective tricyclic triamine. Quantum mechanical calculations for the mechanism of the Diels–Alder reaction between the simplest model compounds are presented. [ABSTRACT FROM AUTHOR]

We report the attempted development of a photoredox-catalyzed α-C–H alkylation reaction of aliphatic amine derivatives, using N-tosylhydrazones as radical alkylating partners. The original intention was to intercept α-aminoalkyl radical intermediates with N-tosylhydrazones, followed by the expulsion of a sulfonyl radical by β-scission to generate N-H diazene species. Facile denitrogenation of these intermediates would remove all traces of the hydrazone moiety and provide a net C–H alkylation process. However, our plans were derailed by issues with the low reactivity of N-tosylhydrazones toward intermolecular capture by nucleophilic radicals, and several unexpected side reactions. Our findings, though unsuccessful, do serve to identify challenges for future researchers attempting to develop similar transformations. [ABSTRACT FROM AUTHOR]

5‐Acetyl‐3‐cyano‐6‐methyl‐4‐(2‐phenylethenyl)pyridine‐2(1H)‐thione (2) was synthesized by interaction of cinnamylidene‐2‐cyanothioacetamide 1 and acetylacetone or via one‐pot reaction of E‐cinnamaldehyde, 2‐cyanothioacetamide, and acetylacetone. Reaction of 2 with ethyl iodide (3a) or N‐chloroacetyl derivative of aromatic amines 3b–e in boiling ethanol containing sodium ethoxide gave the corresponding thioether 4a and 5‐acetyl‐3‐amino‐2‐(N‐arylcarbamoyl)‐6‐methyl‐4‐(2‐phenylethenyl)thieno[2,3‐b]pyridines 5b–e, respectively. Compound 5e was reacted with 2,5‐dimethoxytetrahydrofuran or triethyl orthoformate to furnish pyrrolylthienopyyridine 6 or pyrdiothienopyrimidinone 7, respectively. The photophysical properties of 5b, 5c, 5e, and 7 were fully studied and the obtained results included herein. The fluorescence data confirmed that compounds 5b, 5c, 5e, and 7 exhibit aggregation‐induced emission behavior with high absolute quantum yields. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: An efficient method for asymmetric synthesis of acyclic α‐tertiary amine derivatives has been achieved through enantioselective aminations of α‐branched ynones with azodicarboxylates enabled by chiral phosphoric acid catalysis. Moreover, kinetic resolution of racemic starting material was realized under these conditions, which gave access to valuable enantioenriched α‐substituted ketones. A wide array of α‐aryl and alkyl‐substitutions, and the substituted alkynyl groups were well compatible with this method, producing both the amination products and the recovered ketones with good to high enantioselectivities. [ABSTRACT FROM AUTHOR]

Enantioselective construction methods of chiral derivatives of α-tertiary amines using acyclic and cyclic trifluoromethylketimines are considered. The importance of a trifluoromethyl group in the structure of ketimine substrates for effective asymmetric addition of C-nucleophilic reagents in the presence of metal complex catalysts or organocatalysts is emphasized. The practical application of these chiral products in medicinal chemistry is covered. [ABSTRACT FROM AUTHOR]

Vicinal carboamination of carbon‐carbon multiple bonds is a highly reliable and efficient practical strategy for the quick preparation of valuable and diverse amine derivatives starting from simple synthons. The last decade has witnessed numerous practical methods employing transition metal carboamination approaches of alkenes and allenes for the synthesis of these N‐bearing entities. Driven by the renaissance of transition metal catalysis, inter‐and intramolecular carboamination of alkenes and allenes comprising concomitant C−N and C−C bond formation has been studied extensively. Interestingly, existing reviews describing developments on carboamination of alkenes are mostly reaction path specific and confined to a particular metal catalyst. Whereas, guiding congregation of literature on carboamination of allene is not documented. In this review, different conceptual approaches will be discussed and examples from the recent literature will be presented with special focus to the detailed reaction mechanism. [ABSTRACT FROM AUTHOR]

The sulfated polyborate catalyzed an efficient and chemoselective N-tert-butyloxycarbonylation of amines under ultrasonic irradiation is developed. A broad substrate scope has been demonstrated for N-Boc protection of various primary/secondary amines. It allows converting several aliphatic/aryl/heteroaryl amines, amino alcohol, aminoester, and chiral amines to their N-Boc-protected derivatives under solvent-free conditions with excellent yields. The protocol has several advantages such as easy catalyst, and product isolation, short reaction time, excellent yields, outstanding chemoselectivity, and catalyst recyclability, among others. This makes the process practicable, economical, and environmentally benign. [ABSTRACT FROM AUTHOR]

The synthesis of highly functionalized piperidine derivatives using amine functionalized maltitol‐cored dendritic polymer (MAL‐G0) in acetonitrile as the reaction medium is reported. A variety of piperidine derivatives were synthesized and the reaction gave an excellent yield of 89%–95%. The highly functionalized nature of the catalyst provided large number of active sites which resulted in good yield within a short period of time. Maltitol is a carbohydrate polyol system which was chosen here as the core for the synthesis of the dendritic catalyst; it was an effective approach for the preparation of piperidine like medicinal compounds. Maltitol‐cored dendritic polymer was effectively synthesized and characterized using GPC, TG, UV–Visible, IR, and NMR techniques and also all the synthesized piperidine derivatives were characterized using LCMS, IR, and NMR techniques. [ABSTRACT FROM AUTHOR]

The Tsuji‐Trost Reaction is a palladium‐catalysed allylation of nucleophiles that consists in the reaction of a nitrogen, carbon or oxygen‐based nucleophiles with an allylic substrate bearing a leaving group. Here we present the use of 2‐nitrosulfonamide derivatives as nucleophile, which are reactive under mild conditions. 2‐nitrosulfonyl groups are well‐known dual protective activator groups easy to introduce in any type of amine substrates. The resulting 2‐nitrosulfonamide derivatives are ideal substrates for the Tsuji‐Trost reaction to afford a convenient and flexible access to primary and dissymmetric secondary allyl amines. The optimised procedure is flexible (for solvent, temperature, functional groups) and has been applied with good to excellent yield to access to a wide range of allyl amine derivatives. [ABSTRACT FROM AUTHOR]

The Ir-catalyzed enantioselective addition of an N-methyl C–H bond of 2-(methylamino)pyridine derivatives to α-trifluoromethylstyrenes proceeded via C–H activation to give chiral γ-branched amine derivatives having a trifluoromethyl-substituted stereocenter. It was found that a bulky and electron-withdrawing group at the 3-position of 2-(methylamino)pyridines was necessary for the present C–H addition reaction catalyzed by a cationic iridium/chiral bisphosphine complex. [ABSTRACT FROM AUTHOR]

Chelating resin from naturally occurring polysaccharides like Tamarind Kernel Powder (TKP) has been synthesized. This TKP resin is highly selective, hydrophilic and biodegradable. Secondary amine derivative of tamarind kernel powder can be used as a metal ion exchanger and also as a scavenger for heavy metal ions from the effluent samples of metallurgical industries. A suitable and cost-effective method has been employed to reach the result of this experiment. L-isoleucine acts as the backbone on the tamarind kernel powder in dioxane medium. The selective chelating resins and ion exchange resins have been used in the removal of harmful heavy metal ions from effluent samples of metallurgical and mineral industries. [ABSTRACT FROM AUTHOR]

A visible light‐induced photocyanation of tertiary amines by a stable, less‐toxic and user‐friendly CN reagent cyanobenziodoxolone (CBX) was developed. This cyanation process does not require any photocatalyst, oxidant, base or additives, representing a set of extremely mild and succinct reaction conditions and a broad substrate scope. In addition to the frequently used N‐aryl amine derivatives, more challenging tertiary aliphatic amines (modified by a α‐silyl substituent) can also be photocyanated smoothly. Mechanistic studies reveal that the cyanation reaction is enabled by an electron donor–acceptor (EDA) complex formed by the interaction between the amine and the cyanobenziodoxolone reagent. [ABSTRACT FROM AUTHOR]