Nucleophilic Addition Of Amines Research Articles

Surface Modification of Polyethylene Separator for Li-Ion Batteries via Imine Formation

Porous polyethylene (PE) polymer film is a representative material for separators in Li-ion batteries (LIBs). Although PE separators are widely used in commercial LIBs owing to several advantages such as chemical stability, low cost, and good processability, the material still suffers from poor wettability to organic liquid electrolytes and low thermal stability. In this study, a facile surface modification method via the nucleophilic addition of amine in a solution is proposed. To improve the electrolyte wettability and thermal stability of the PE separators, a carbonyl group (C=O) was introduced onto the surface by pretreatment. Then, an imine functional group (R–N=C) was created by the conversion reaction between the carbonyl and amine groups (R-NH2) in a poly(ethylene glycol) bis(amine) solution. By including the formed imine group onto the surface, the surface-modified PE separator exhibited enhanced wettability and thermal stability. The chemical surface treatment transformed the PE separator from hydrophobic to hydrophilic, resulting in the increased ionic conductivity of the electrolyte and rate capability of the cells without any negative effect on the physical and electrochemical properties of the separator.

N-Heterocyclic Carbene Gold Complexes Active in Hydroamination and Hydration of Alkynes

Until the year 2000, gold compounds were considered catalytically inert. Subsequently, it was found that they are able to promote the nucleophilic attack on unsaturated substrates by forming an Au–π-system. The main limitation in the use of these catalytic systems is the ease with which they decompose, which is avoided by stabilization with an ancillary ligand. N-heterocyclic carbenes (NHCs), having interesting σ-donor capacities, are able to stabilize the gold complexes (Au (I/III) NHC), favoring the exploration of their catalytic activity. This review reports the state of the art (years 2007–2022) in the nucleophilic addition of amines (hydroamination) and water (hydration) to the terminal and internal alkynes catalyzed by N-heterocyclic carbene gold (I/III) complexes. These reactions are particularly interesting both because they are environmentally sustainable and because they lead to the production of important intermediates in the chemical and pharmaceutical industry. In fact, they have an atom economy of 100%, and lead to the formation of imines and enamines, as well as the formation of ketones and enols, all important scaffolds in the synthesis of bioactive molecules, drugs, heterocycles, polymers, and bulk and fine chemicals.

Substituted acyl thioureas and acyl thiosemicarbazides: synthesis and biological activity (minireview)

Acyl isothiocyanates and their functional derivatives (acyl thioureas and acyl thiosemicarbazides) are an important group of organic compounds that are widely used in the synthesis of heterocycles and in chemistry as catalysts, ligands, colorimetric hemosensors, etc. In recent years, there has been an increased interest towards this class of compounds as promising biologically active compounds, especially since the latest advances in medicinal chemistry for them are not sufficiently studied.
 The aim. To summarize and systematize information for the last 10 years on methods of synthesis and biological activity of substituted acyl thioureas and acyl thiosemicarbazides.
 Materials and methods. Web-tools for finding scientific information (Reaxys, Scopus, Google Scholar, ScienceResearch, SciFinder, Web of Science, etc.).
 Results and discussion. Literature sources related to the methods of synthesis of substituted acyl thioureas and acyl thiosemicarbazides were systematized and analyzed. The main approaches for the formation of these compounds are revealed: stepwise formation from carboxylic acids, through acyl chlorides and acyl isothiocyanates followed by nucleophilic addition of amines or hydrazides of carboxylic acids ("one-pot synthesis"), nucleophilic addition of amines or hydrazides of carboxylic acids directly to acyl isothiocyanates and parallel microwave synthesis using acyl isothiocyanates and amines as reagents. The possibility of their use as ligands for the formation of complex compounds with transition metal ions was discussed. In the review biological activity of these structures, namely antimicrobial, fungicidal, antitumor, antiviral, antifungal and other activities was detailazed.
 Conclusions. The basic approaches to the synthesis of substituted acylthuoureas and acyl thiosemicarbazides which include the application of carboxylic acids, their derivatives (acyl halides and isothiocyanates) and N-nucleophiles as initial compounds were discussed. It was shown that aforementioned class of the compounds reveals the versatile biological activity and are promising for further structural modification aimed to the search of novel drugs

Primary Amine Nucleophilic Addition to Nitrilium Closo-Dodecaborate [B12H11NCCH3]-: A Simple and Effective Route to the New BNCT Drug Design.

In the present work, a convenient and straightforward approach to the preparation of borylated amidines based on the closo-dodecaborate anion [B12H11NCCH3NHR]−, R=H, Alk, Ar was developed. This method has two stages. A nitrile derivative of the general form [B12H11NCCH3]− was obtained, using a modified technique, in the first stage. On the second stage the resulting molecular system interacted with primary amines to form the target amidine products. This approach is characterised by a simple chemical apparatus, mild conditions and high yields of the final products. The mechanism of the addition of amine to the nitrile derivative of the closo-dodecaborate anion was studied, using quantum-chemical methods. The interaction between NH3 and [B12H11NCCH3]− ammonia was chosen as an example. It was found that the structure of the transition state determines the stereo-selectivity of the process. A study of the biological properties of borylated amidine sodium salts indicated that the substances had low toxicity and could accumulate in cancer cells in significant amounts.

Primary amine nucleophilic addition to nitrilium clo-so-dodecaborate [B12H11NCCH3]–. A simple and effective route to the new BNCT drug design.

Primary amine nucleophilic addition to nitrilium clo-so-dodecaborate [B12H11NCCH3]–. A simple and effective route to the new BNCT drug design.

Primary amine nucleophilic addition to nitrilium clo-so-dodecaborate [B12H11NCCH3]–. A simple and effective route to the new BNCT drug design.

Primary amine nucleophilic addition to nitrilium clo-so-dodecaborate [B12H11NCCH3]–. A simple and effective route to the new BNCT drug design.

Primary amine nucleophilic addition to nitrilium clo-so-dodecaborate [B12H11NCCH3]–. A simple and effective route to the new BNCT drug design.

Primary amine nucleophilic addition to nitrilium clo-so-dodecaborate [B12H11NCCH3]–. A simple and effective route to the new BNCT drug design.

Efficient Deep Blue Platinum Acetylide Phosphors with Acyclic Diaminocarbene Ligands.

Here we report five blue-phosphorescent platinum bis-phenylacetylide complexes with an investigation of their photophysical and electrochemical attributes. Three of the complexes (1-3) are of the general formula cis-Pt(CNR)2 (C≡CPh)2 , in which CNR is a variably substituted isocyanide and C≡CPh is phenylacetylide. These isocyanide complexes serve as precursors for complexes of the general formula cis-Pt(CNR)(ADC)(C≡CPh)2 (4 and 5), in which ADC is an acyclic diaminocarbene installed by amine nucleophilic addition to one of the isocyanides. All of the complexes exhibit deep blue phosphorescence with λmax ∼430 nm in poly(methyl methacrylate) (PMMA) thin films. Whereas isocyanide complexes 1-3 exhibit modest photoluminescence quantum yields (ΦPL ), incorporation of one acyclic diaminocarbene ligand results in a three-fold to 16-fold increase in ΦPL while still maintaining an identical deep blue color profile.

Direct Synthesis of β-Aminoenals through Reaction of 1,2,3-Triazine with Secondary Amines

Simple and direct nucleophilic addition of secondary amines, including imidazole, to 1,2,3-triazine under mild reaction conditions (THF, 25-65 °C, 12-48 h), requiring no additives, cleanly provides β-aminoenals 4 in good yields (21 examples, 31-79%). The reaction proceeds by amine nucleophilic addition to C4 of the 1,2,3-triazine, in situ loss of N2, and subsequent imine hydrolysis to provide 4.

The Origin of Anti-Markovnikov Regioselectivity in Alkene Hydroamination Reactions Catalyzed by [Rh(DPEphos)](.).

The development of regioselective anti-Markovnikov alkene's hydroamination is a long-standing goal in catalysis. The [Rh(COD)(DPEphos)](+) complex is the most general and regioselective group 9 catalyst for such a process. The reaction mechanism for intermolecular hydroamination of alkenes catalyzed by [Rh(DPEphos)](+) complex is analyzed by means of DFT calculations. Hydroamination (alkene vs. amine activation routes) as well as oxidative amination pathways are analyzed. According to the computational results the operating mechanism can be generally described by alkene coordination, amine nucleophilic addition, proton transfer through the metal center and reductive elimination steps. The mechanism for the formation of the oxidative amination side product goes via a β-elimination after the nucleophilic addition and metal center protonation steps. The origin of the regioselectivity for the addition process (Markovnikov vs. anti-Markovnikov additions) is shown to be not charge but orbitally driven. Remarkably, η(2) to η(1) slippage degree on the alkene coordination mode is directly related to the regioselective outcome.

Grafting of adipic anhydride to carbon nanotubes through a Diels-Alder cycloaddition/oxidation cascade reaction

Different reactions have been reported for the successful functionalization of carbon nanotubes (CNT). The Diels-Alder cycloaddition is recognized as a plausible chemical approach, but few reports are known where this strategy has been used. In this study, the functionalization was performed by 1,3-butadiene generated from 3-sulfolene under heating conditions in diglyme. This simple and easily scalable method resulted in functionalized CNT with mass losses of 10–23% by thermogravimetric analysis (nitrogen atmosphere). The functionalization was also supported by acid-base titration, elemental analysis, temperature programmed desorption and X-ray photoelectron spectroscopy. The high content in oxygen detected on the CNT surface was assigned to anhydride formation due to a cascade oxidation of the alkene groups generated in the cycloaddition reaction. The complete evolution of the alkene leads to a grafting density of 4.2 mmol g−1 for the anhydride moiety. Ab-initio calculations in CNT model systems indicate that the Diels-Alder addition of butadiene is a feasible process and that subsequent oxidation reactions may result in the formation of the anhydride moiety. The presence of the anhydride group is a valuable asset for grafting a multitude of complex molecules, namely through the nucleophilic addition of amines.

Nucleophilic addition of amines, alcohols, and thiophenol with epoxide/olefin using highly efficient zirconium metal organic framework heterogeneous catalyst

Zr based MOF exhibited excellent activity in the ring opening of epoxides/nucleophilic addition of activated olefins with wide range of nucleophiles.

Multistep flow synthesis of 5-amino-2-aryl-2H-[1,2,3]-triazole-4-carbonitriles.

1,2,3-Triazole has become one of the most important heterocycles in contemporary medicinal chemistry. The development of the copper-catalyzed Huisgen cycloaddition has allowed the efficient synthesis of 1-substituted 1,2,3-triazoles. However, only a few methods are available for the selective preparation of 2-substituted 1,2,3-triazole isomers. In this context, we decided to develop an efficient flow synthesis for the preparation of various 2-aryl-1,2,3-triazoles. Our strategy involves a three-step synthesis under continuous-flow conditions that starts from the diazotization of anilines and subsequent reaction with malononitrile, followed by nucleophilic addition of amines, and finally employs a catalytic copper(II) cyclization. Potential safety hazards associated with the formation of reactive diazonium species have been addressed by inline quenching. The use of flow equipment allows reliable scale up processes with precise control of the reaction conditions. Synthesis of 2-substituted 1,2,3-triazoles has been achieved in good yields with excellent selectivities, thus providing a wide range of 1,2,3-triazoles.

Green chemistry of carbon nanomaterials.

The global trend of looking for more ecologically friendly, "green" techniques manifested itself in the chemistry of carbon nanomaterials. The main principles of green chemistry emphasize how important it is to avoid the use, or at least to reduce the consumption, of organic solvents for a chemical process. And it is precisely this aspect that was systematically addressed and emphasized by our research group since the very beginning of our work on the chemistry of carbon nanomaterials in early 2000s. The present review focuses on the results obtained to date on solvent-free techniques for (mainly covalent) functionalization of fullerene C60, single-walled and multi-walled carbon nanotubes (SWNTs and MWNTs, respectively), as well as nanodiamonds (NDs). We designed a series of simple and fast functionalization protocols based on thermally activated reactions with chemical compounds stable and volatile at 150-200 degrees C under reduced pressure, when not only the reactions take place at a high rate, but also excess reagents are spontaneously removed from the functionalized material, thus making its purification unnecessary. The main two classes of reagents are organic amines and thiols, including bifunctional ones, which can be used in conjunction with different forms of nanocarbons. The resulting chemical processes comprise nucleophilic addition of amines and thiols to fullerene C60 and to defect sites of pristine MWNTs, as well as direct amidation of carboxylic groups of oxidized nanotubes (mainly SWNTs) and ND. In the case of bifunctional amines and thiols, reactions of the second functional group can give rise to cross-linking effects, or be employed for further derivatization steps.

Enhancing sensitivity of ion mobility spectrometry determination of aldehydes by in situ gas phase derivatization with dibutylamine

A simple and fast method for the detection of aldehydes by headspace solid-phase microextraction (HS-SPME) based on nanostructure polypyrrole film coupled to ion mobility spectrometery (IMS) is described. The detection of aldehydes (pentanal, hexanal and heptanal) has been successfully accomplished using in situ chemical derivatization with dibutylamine as the derivatization reagent and IMS. The simultaneous and rapid detection of aldehydes is important, since elevated level of aldehydes is considered as the biomarker of different diseases. The highlight of this method was that it involved an amine nucleophilic addition reaction (which was often considered as Mannich reaction) in gas phase for enhancing IMS sensitivity of aldehydes. Dibutylamine was used as the derivatization reagent driven into the cell by using a syringe pump. The calibration graphs were linear in the range of 2.0–50.0 μg mL−1 with R 2 ≥ 0.99 in aqueous solutions and limit of detections were determined ≤ 1.8 μg mL−1. The RSD% values of the aldehydes determination was ≤ 8 %. Here we have demonstrated that other amine types (butylamine and tributylamine) can derivatize aldehydes and significantly improve the IMS sensitivity of tagged analytes. However, IMS spectrum is complicated by presence of the different product ions in the process.

Metal-free synthesis of 2-aminobenzoxazoles using hypervalent iodine reagent

A facile, simple, mild, and metal-free protocol for the synthesis of 2-aminobenzoxazoles has been developed via C–H bond amination of benzoxazoles with amines through a ring-opening and subsequent ring-closure approach. The reaction was performed in two steps wherein nucleophilic addition of amines across benzoxazoles takes place in the absence of any reagent or catalyst under solvent-free condition, followed by oxidative ring closure using 2-iodoxybenzoic acid as a hypervalent iodine reagent. Various cyclic, acyclic, and functionalized aliphatic amines were well tolerated under optimized reaction conditions and provided good to excellent yield of respective 2-aminobenzoxazoles.

ChemInform Abstract: Amine Nucleophilic Addition to Nitroalkene as a New Practical Approach for the Synthesis of Fully Substituted Isoxazoline‐N‐oxide.

AbstractA one‐pot condensation of nitroalkenes with aldehydes alone or with aldehydes/sulfur ylides leads to formation of various desired fully substituted target compounds.

Synthesis and Characterization of Ammonium Functionalized Porous Poly(glycidyl methacrylate-co-ethylene dimethacrylate) Monoliths for Microscale Analysis and Its Application to DNA Purification

A systematic study of parameters affecting the nucleophilic addition of secondary and tertiary amines on reactive epoxy groups was conducted on porous polymer monoliths. Reaction of small amines like diethylamine (DEA) or triethylamine (TEA) on poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths (poly(GMA-co-EDMA)) allows to prepare anion exchange media. This study aimed to determine optimal and suitable conditions to prepare anion-exchange porous monolith inside 100 microm internal diameter capillary. The reaction kinetic of amine nucleophilic addition on porous poly(GMA-co-EDMA) monoliths was followed by FTIR-ATR spectroscopy. The reactivity of such epoxy-functionalized porous polymers was first determined through a study in pure amine solutions. Thereafter, conditions of reactions (i.e., temperature and time of reaction, solvent composition, concentration of amine) with respect to its further implementation at nanoscale, were optimized through a factorial analysis. The optimization allowed extending conversion yields of epoxy groups up to more than 90% in dilute amine solution within less than 4 hours of reaction for TEA addition. This ion-exchange support with respect to the in-situ light-addressable process of elaboration is specifically designed to be incorporated as biomolecular sample preparation module in microsystem devices. The high loading capacity obtained for the preconcentration of DNA demonstrate the attractivity of this functionalized polymeric porous monolith as solid-phase support to improve the quantity and the efficiency of DNA extraction applied into microscale format like capillaries or lab-on-chip.

Macromolecular Carriers for Methotrexate and Ferrocene in Cancer Chemotherapy

Several drug-carrier polymers were synthesized in this program, including polyaspartamides, ester-amine condensation polymers, and polyamidoamines (PAAs). Functionalized polyaspartamides were obtained in 46–73% yield by an aminolytic ring-opening process resulting from the nucleophilic attack of a number of selected amines on polysuccinimide, which in turn was obtained by a high-temperature polycondensation reaction in the presence of phosphoric acid. These polyaspartamides were characterized by inherent viscosities in the range of 8–26 mL g−1. The ester-amine polymers were obtained in 42–71% yield by base-catalyzed polycondensation reactions under controlled conditions of temperature, in DMSO, so as to ensure the incorporation and integrity of unprotected hydroxyl functional groups in the polymer’s main chain. These polymers were characterized by inherent viscosities in the range of 10–13 mL g−1. PAAs were synthesized by the addition of amine nucleophiles across the double bonds of methylene bisacrylamide (Michael-type addition), under carefully controlled experimental conditions to obtain both amide and secondary amine functions in the water-soluble polymeric main chain. They were obtained in 16–29% yield and characterized by inherent viscosities in the range of 20–26 mL g−1. These three types of polymers are perfectly water-soluble polymeric products which are purified by dialysis (12,000 molecular mass cut-off) and freeze-drying. They are of interest as macromolecular carriers for pharmaceuticals and biologically active agents.

Amine nucleophilic addition to nitroalkene as a new practical approach for the synthesis of fully substituted isoxazoline- N-oxide

The secondary amine nucleophilic addition to the nitroalkene was used to generate the active nitronate intermediate, followed by the sequential addition to aldehyde and ylide, giving the fully substituted isoxazoline- N-oxide in one-pot fashion. Mechanistic studies revealed the equilibrium nature of the diene intermediates, which provide the foundation for the asymmetric synthesis of this interesting heterocycles.