Synthesis Of Diamines Research Articles

Bentonite as eco-friendly natural mineral support for Pd/CoFe2O4 catalyst applied in toluene diamine synthesis

Toluene diamine (TDA) is a major raw material in the polyurethane industry and thus, its production is highly important. TDA is obtained through the catalytic hydrogenation of 2,4-dinitrotoluene (2,4-DNT). In this study a special hydrogenation catalyst has been developed by decomposition cobalt ferrite nanoparticles onto a natural clay-oxide nanocomposite (bentonite) surface using a microwave-assisted solvothermal method. The catalyst particles were examined by TEM and X-ray diffraction. The palladium immobilized on the bentonite crystal surface was identified using an XRD and HRTEM device. The obtained catalyst possesses the advantageous property of being easily separable due to its magnetizability on a natural mineral support largely available and obtained through low carbon- and energy footprint methods. The catalyst demonstrated outstanding performance with a 2,4-DNT conversion rate exceeding 99% along with high yields and selectivity towards 2,4-TDA and all of this achieved within a short reaction time. Furthermore, the developed catalyst exhibited excellent stability, attributed to the strong interaction between the catalytically active metal and its support. Even after four cycles of reuse, the catalytic activity remained unaffected and the Pd content of the catalyst did not change, which indicates that the palladium component remained firmly attached to the magnetic support's surface.

Towards Machine Learning in Heterogeneous Catalysis-A Case Study of 2,4-Dinitrotoluene Hydrogenation.

Utilization of multivariate data analysis in catalysis research has extraordinary importance. The aim of the MIRA21 (MIskolc RAnking 21) model is to characterize heterogeneous catalysts with bias-free quantifiable data from 15 different variables to standardize catalyst characterization and provide an easy tool to compare, rank, and classify catalysts. The present work introduces and mathematically validates the MIRA21 model by identifying fundamentals affecting catalyst comparison and provides support for catalyst design. Literature data of 2,4-dinitrotoluene hydrogenation catalysts for toluene diamine synthesis were analyzed by using the descriptor system of MIRA21. In this study, exploratory data analysis (EDA) has been used to understand the relationships between individual variables such as catalyst performance, reaction conditions, catalyst compositions, and sustainable parameters. The results will be applicable in catalyst design, and using machine learning tools will also be possible.

Alkene Difunctionalization Directed by Free Amines: Diamine Synthesis via Nickel-Catalyzed 1,2-Carboamination

Alkene Difunctionalization Directed by Free Amines: Diamine Synthesis via Nickel-Catalyzed 1,2-Carboamination

Synthesis of Di-amine Functionalized Lignin Derivative and Its Removal Ability for Heavy Metal Ions

In this study, di-amine functionalized lignin (DAL) was prepared by a two-step reaction and its adsorption behavior for metal ions (Pb(II), Cu(II) and Cd(II)) was investigated. The chemical structural analysis of DAL by FT-IR, XPS and 1H NMR confirmed that the di-amine groups were successfully introduced into lignin. The prepared DAL exhibited enhanced molecular weight, and thermal stability. For adsorption behavior, DAL has a higher adsorption capacity for cationic heavy metal ions under neutral conditions than acidic conditions. In addition, it was confirmed that adsorption capacity of Pb(II) ions by DAL was better than those of Cu(II) and Cd(II) ions. This is due to an adsorption mechanism in which DAL introduced with a lone pair of N-functional group in lignin is chelated with metal ions, which showed that DAL was a promising adsorbent for wastewater treatment. Therefore, it was suggested that the lignin-based di-amine derivative prepared in this study could provide an opportunity to increase the utility of novel lignin-based biomaterials as a low-cost biosorbent.

Diamine Synthesis via the Nitrogen-Directed Azidation of σ- and π-C-C Bonds.

Diamines are essential building blocks for the synthesis of agrochemicals, drugs, and organic materials, yet their synthesis remains challenging, as both nitrogens need to be differentiated and diverse substitution patterns (1,2, 1,3, or 1,4) are required. We report herein a new strategy giving access to 1,2, 1,3, and 1,4 amido azides as orthogonally protected diamines based on the nitrogen-directed diazidation of alkenes, cyclopropanes, and cyclobutanes. Commercially available copper thiophene-2-carboxylate (CuTc, 2 mol %) as catalyst promoted the diazidation of both π and σ C-C bonds within 10 min in the presence of readily available oxidants and trimethylsilyl azide. Selective substitution of the formed α-amino azide by carbon nucleophiles (electron-rich aromatic, malonate, organosilicon, organoboron, organozinc, and organomagnesium compounds) was then achieved in a one-pot fashion, leading to the formation of 1,2-, 1,3-, and 1,4-diamines with the amino groups protected orthogonally as an amide/carbamate and an azide.

Regioselective Three-Component Synthesis of Vicinal Diamines via 1,2-Diamination of Styrenes.

The vicinal diamine motif plays a significant role in natural products, drug design, and organic synthesis, and development of synthetic methods for the synthesis of diamines is a long-standing interest. Herein, we report a regioselective intermolecular three-component vicinal diamination of styrenes with acetonitrile and azodicarboxylates. The diamination products can be produced in moderate to excellent yields via the Ritter reaction. Synthetic applications and theoretical studies of this reaction have been conducted.

Diamine Biosynthesis: Research Progress and Application Prospects.

Diamines are important monomers for polyamide plastics; they include 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, and 1,6-diaminohexane, among others. With increasing attention on environmental problems and green sustainable development, utilizing renewable raw materials for the synthesis of diamines is crucial for the establishment of a sustainable plastics industry. Recently, high-performance microbial factories, such as Escherichia coli and Corynebacterium glutamicum, have been widely used in the production of diamines. In particular, several synthetic pathways of 1,6-diaminohexane have been proposed based on glutamate or adipic acid. Here, we reviewed approaches for the biosynthesis of diamines, including metabolic engineering and biocatalysis, and the application of bio-based diamines in nylon materials. The related challenges and opportunities in the development of renewable bio-based diamines and nylon materials are also discussed.

Visible-light-induced selectivity controllable synthesis of diamine or imidazoline derivatives by multicomponent decarboxylative radical coupling reactions

A visible-light-induced and photoredox-catalyzed three-component selectivity controllable synthesis of vicinal diamines and imidazoles from readily available starting materials under mild reaction conditions has been realized.

Synthesis of diamine functionalised graphene oxide and its application in the fabrication of electrically conducting reduced graphene oxide/polymer nanocomposite films.

The focus of research in diamine functionalised graphene oxide (GO) has been limited to the use of diamines either as crosslinker or to achieve simultaneous functionalisation, reduction and stitching of GO sheets, especially in the case of ethylene diamine (EDA). Controlling the extent of stitching and functionalisation has to date remained a challenge. In particular, synthesis of colloidally stable monofunctionalised GO–NH2 with dangling amine groups using diamines has remained elusive. This has been the limiting factor towards the utility of EDA functionalised GO (GO–NH2) in the field of polymer-based nanocomposites. We have synthesised colloidally stable GO–NH2 with dangling amine groups and subsequently demonstrated its utility as a surfactant to synthesize colloidally stable waterborne polymer nanoparticles with innate affinity to undergo film formation at room temperature. Thermally annealed dropcast polymer/GO–NH2 nanocomposite films exhibited low surface roughness (∼1 μm) due to the homogeneous distribution of functionalised GO sheets within the polymer matrix as observed from confocal laser scanning microscopy, scanning electron microscopy and transmission electron microscopy. The films exhibited considerable electrical conductivity (∼0.8 S m−1), demonstrating the potential of the GO–NH2/polymer nanocomposite for a wide range of applications.

Diamine Synthesis via a Diastereoselective Aminoalkylation of Aldehydes

Diamine Synthesis via a Diastereoselective Aminoalkylation of Aldehydes

Synthesis of Diamine Containing Chalcone Structure by Nitroammoniation and Aldol Condensation

In this paper, the structure of the photosensitive diamines was designed and the method of synthesizing such diamines was investigated. The 1-(3-aminophenyl)-3-(4-aminophenyl)-2-propen-1-one analyzed by elemental analysis and infrared analysis was synthesized through two-step experiments with Aldol condensation and Nitroammoniation process. Through the experiment the optimum reaction conditions are raw material ratio of 1:1, anhydrous ethanol dosage of 60 ml, 10 % NaOH dosage of 10 ml and reaction temperature of 25°C for 4h. The yield was about 55.4 %.

Enantioselective Organocatalytic Amine-Isocyanate Capture-Cyclization: Regioselective Alkene Iodoamination for the Synthesis of Chiral Cyclic Ureas.

Ureas of chiral diamines are prominent features of therapeutics, chiral auxiliaries, and intermediates in complex molecule synthesis. Although many methods for diamine synthesis are available, metal-free enantioselective alkene functionalizations to make protected 1,2- and 1,3-diamines from simple achiral starting materials are rare, and a single reagent that accesses a cross-section of each congener with high enantiomeric excess is not available. We describe a method to synthesize enantioenriched cyclic 5- and 6-membered ureas from allylic amines and an isocyanate using a C2-symmetric BisAmidine (BAM) catalyst that delivers N-selectivity from an ambident sulfonyl imide intermediate, overcoming electronic and steric deactivation at nitrogen. The geometry of 1,2-disubstituted alkenes is correlated to 5-exo and 6-endo cyclizations without altering alkene face selectivity, which is unexpectedly opposite that observed with O-nucleophiles. Straightforward product manipulations to diamine and imidazolidinone derivatives are underscored by the synthesis of an NK1 antagonist.

Synthesis and Study of Thermo Stability Properties of Novel Polyamides

Aromatic and aliphatic diamines are one of the main components in polyamides, polyimides, polyurea and polyurethanes. To prepare high performance and well featured materials, attempts is directed to the novel diamine synthesis routes in which soluble thermo-resistant, soluble and easy process polymers are obtained. To solubility improvement and decreasing the glass transition temperature, existing flexible bonds in polymer repeating unit are necessary. These bonds decrease the internal rotational energies. Using heterocyclic rings or introducing of polar functional groups such as amide in the main synthetic polymer chain results in convenient polarity and solubility of polymer. Until now, massive investigations have been conducted to prepare aromatic monomers with high solubility and processing capabilities. In the current study, our main aim is to prepare diamines which are applicable in thermo-resistant polymers including polyamide, polyimide, polyurea and polyurethanes.

Selective mono- and diamination of some polyhalogenbenzenes in anhydrous ammonia

Abstract Aminodefluorination of polyhalogenbenzenes (chloropentafluoro-, 1,3-dichlorotetrafluoro-, sym -trichlorotrifluoro-, 1,2,3,5-tetrafluoro- and 1,2,4,5-tetrafluoro-3-trifluoromethylbezenes) in anhydrous ammonia was investigated. The optimal conditions for selective preparation of mono- and diamino derivatives, which are ensured by the reaction temperature, were elucidated. In some examples of diamine synthesis, in order to improve the selectivity of second aminodefluorination, it is advisable to separate the isomeric monoamino derivatives produced in the first step of the synthesis.

Enantioselective Diamination with Novel Chiral Hypervalent Iodine Catalysts

Vicinal diamines constitute one the most important functional motif in organic chemistry because of its wide occurrence in a variety of biological and pharmaceutical molecules. We report an efficient metal‐free, highly stereoselective intramolecular diamination using a novel chiral hypervalent iodine reagent together with its application as an efficient catalyst for the synthesis of diamines.

Synthesis of Differentially Substituted 1,2-Diamines through Advances in C–H Amination Technology

A general, high yielding method for the synthesis of 1,2-diamine derivatives is described that capitalizes on selective, rhodium-catalyzed C-H insertion of hydroxylamine-based sulfamate esters. The resulting Troc-protected oxathiadiazinane heterocycles are easily modified and can be reduced under the mild action of NaI to afford differentially substituted diamine products. This technology offers a number of salient improvements over related C-H and π-bond amination tactics for diamine synthesis.

Understanding the Interplay of Weak Forces in [3,3]-Sigmatropic Rearrangement for Stereospecific Synthesis of Diamines

Chiral diamines are important building blocks for constructing stereoselective catalysts, including transition metal based catalysts and organocatalysts that facilitate oxidation, reduction, hydrolysis, and C-C bond forming reactions. These molecules are also critical components in the synthesis of drugs, including antiviral agents such as Tamiflu and Relenza and anticancer agents such as oxaliplatin and nutlin-3. The diaza-Cope rearrangement reaction provides one of the most versatile methods for rapidly generating a wide variety of chiral diamines stereospecifically and under mild conditions. Weak forces such as hydrogen bonding, electronic, steric, oxyanionic, and conjugation effects can drive this equilibrium process to completion. In this Account, we examine the effect of these individual weak forces on the value of the equilibrium constant for the diaza-Cope rearrangement reaction using both computational and experimental methods. The availability of a wide variety of aldehydes and diamines allows for the facile synthesis of the diimines needed to study the weak forces. Furthermore, because the reaction generally takes place cleanly at ambient temperature, we can easily measure equilibrium constants for rearrangement of the diimines. We use the Hammett equation to further examine the electronic and oxyanionic effects. In addition, computations and experiments provide us with new insights into the origin and extent of stereospecificity for this rearrangement reaction. The diaza-Cope rearrangement, with its unusual interplay between weak forces and the equilibrium constant of the reaction, provides a rare opportunity to study the effects of the fundamental weak forces on a chemical reaction. Among these many weak forces that affect the diaza-Cope rearrangement, the anion effect is the strongest (10.9 kcal/mol) followed by the resonance-assisted hydrogen-bond effect (7.1 kcal/mol), the steric effect (5.7 kcal/mol), the conjugation effect (5.5 kcal/mol), and the electronic effect (3.2 kcal/mol). Based on both computation and experimental data, the effects of these weak forces are additive. Understanding the interplay of the weak forces in the [3,3]-sigmatropic reaction is interesting in its own right and also provides valuable insights for the synthesis of chiral diamine based drugs and catalysts in excellent yield and enantiopurity.

Palladium‐Catalyzed Vicinal Difunctionalization of Internal Alkenes: Diastereoselective Synthesis of Diamines

Internal affairs: the first general palladium-catalyzed intermolecular diamination of internal alkenes employs different nitrogen sources, which add to the alkene in a regio- and diastereoselective fashion. The resulting diamination products can be converted directly into a known ligand motif.

Chemo- and enantioselective Rh-catalysed hydrogenation of 3-methylene-1,2-diazetidines: application to vicinal diamine synthesis

Rhodium catalysed hydrogenation of 3-methylene-1,2-diazetidines with a range of chiral ligands is reported. Using Mandyphos, excellent levels of chemo- and enantioselectivity (up to 89% ee) can be achieved. Reductive cleavage of the derived 3-substituted 1,2-diazetidine with LiDBB provides the enantioenriched biscarbamate protected 1,2-diamine.

ChemInform Abstract: Improved Ruthenium‐Catalyzed Amination of Alcohols with Ammonia: Synthesis of Diamines and Amino Esters.

AbstractThe homogeneous selective catalytic diamination of primary and secondary diols with ammonia gives the corresponding diamines in high yields.