Cyclohexylamine Research Articles

Bioamination of alkane with ammonium by an artificially designed multienzyme cascade

Biocatalytic C–H amination is one of the most challenging tasks. C-H amination reaction can hardly be driven efficiently by solely one enzyme so far. Thus, enzymatic synergy represents an alternative strategy. Herein, we report an “Artificially Bioamination Pathway” for C–H amination of cyclohexane as a model substrate. Three enzymes, a monooxygenase P450BM3 mutant, an alcohol dehydrogenase ScCR from Streptomyces coelicolor and an amine dehydrogenase EsLeuDH from Exiguobacterium sibiricum, constituted a clean cascade reaction system with easy product isolation. Two independent cofactor regeneration systems were optimized to avoid interference from the endogenous NADH oxidases in the host E. coli cells. Based on a stepwise pH adjustment and ammonium supplement strategy, and using an in vitro mixture of cell-free extracts of the three enzymes, cyclohexylamine was produced in a titer of 14.9 mM, with a product content of up to 92.5%. Furthermore, designer cells coexpressing the three required enzymes were constructed and their capability of alkane bio-amination was examined. This artificially designed bioamination paves an attractive approach for enzymatic synthesis of amines from accessible and cheap alkanes.

Probing locations of organic structure-directing agents (OSDAs) and host-guest interactions in CHA-type SAPO-34/44

In this work, we have synthesized four SAPO-34/44 (framework type code: CHA) samples by utilizing different organic structure-directing agent (OSDA) such as cyclohexylamine (CA), n-butylamine (BA), diisopropylamine (DIPA), and dipropylamine (DPA). An approach combining Rietveld refinement and simulated annealing has been successfully applied to determine the location of the individual OSDA and the host (inorganic framework)-guest (OSDA) interaction. The final Rietveld refinements show that 1) one cha cage can be occupied by either two OSDAs (CA and BA) in the up-and-down arrangement or one OSDA (DIPA and DPA) in the longitudinal configuration and 2) the classical hydrogen bond between CA/BA and the inorganic framework in SAPO-44-CA and SAPO-34-BA could be identified. The host-guest interactions among these four samples are also investigated by FT-IR, which are consistent with Rietveld refinement results. The approach employed here could be applicable for the host-guest investigation in other crystalline porous materials.

One-pot synthesis of new $N$-(1-methylpyridin-4(1$H)$-ylidene)amine ligands for palladium-catalyzed Heck coupling reaction

A series of new derivatives of N-(1-methylpyridin-4(1H)-ylidene)amines, [L1]-[L5], were synthesized and characterized by FTIR, NMR, MS, and XRD analysis. These targeted compounds were synthesized by the melt reaction between N-methylated-4-chloropyridinium triflate and corresponding amines (1-naphthyl amine, o-ansidine, 2-nitroaniline, p-ansidine, and cyclohexyl amine) followed by the addition of sodium hydride in dichloromethane in the same pot. These highly electron-donating N-(1-methylpyridin-4(1H)-ylidene)amine ligands considerably improve the catalytic activity of palladium acetate towards Heck-Mizoroki carbon-carbon cross-coupling reactions.

To direct the self-assembly of AIEgens by three-gear switch: Morphology study, amine sensing and assessment of meat spoilage

Abstract In this study, we synthesized a class of positional isomers by attaching a carboxylic group in different sites (para-, meta- and ortho-position) of an aromatic core. The isomers undergo both aggregation-induced emission (AIE) and intramolecular charge transfer (ICT) mechanisms, as proved by their photoluminescence (PL) behaviour. Changing the position of the carboxylic group will adjust the dipole–dipole direction, which further controls the self-assembled architecture: The morphology undergoes a transition from 1D nanowire to 2D microsheet, and even to 3D microcube. The benzoic acid moiety of the AIE isomers has strong affinity to amines, and adsorbing amines leads to spectral changes including hypochromatic shift and emission quenching. The sensing mechanism was studied by density functional theory (DFT), which reveals that the amine-responsive fluorescence can be ascribed to the weakened ICT effect. A prototype of amine sensor based on m-DB self-assemblies was developed accordingly, showing a remarkable quenching efficiency as high as 85.4%. A linear relation was obtained from the quantitative determination of amine, offering a low detection limit of 2.02 Pa. It can also respond to other organic amines such as diisopropylamine (DIPA), triethylamine (TEA), isopropylamine (IPA) and cyclohexylamine (CHA). Finally, the practicality of the sensor was also demonstrated: When placing the sensing film beside the spoiled meat, the spectrum shows a remarkable fluorescence quenching; in contrast, fresh meat samples have induced a much lower quenching efficiency. This demonstrates that the AIE isomers have a great potential to serve as indicators for meat spoilage.

Solvent-free, catalyst-free aza-Michael addition of cyclohexylamine to diethyl maleate: Reaction mechanism and kinetics

The aza-Michael reaction is the addition of an amine to an electron deficient C=C double bond. This reaction is also used in the synthesis of precursors of polymeric networks. In this study, we paid attention to the kinetics and mechanism of the aza-Michael addition of cyclohexylamine (CHXA) to diethyl maleate (DEM) performed as a solvent-free, catalyst-free reaction and to concurrent reactions. In situ Raman spectroscopy, NMR spectroscopy and gas chromatography/mass spectrometry have shown the occurrence of three simultaneous reactions: (i) the aza-Michael addition of CHXA to DEM leading to diethyl 2-(cyclohexylamino)succinate, (ii) isomerization of DEM to diethyl fumarate (DEF), and (iii) the aza-Michael addition of CHXA to DEF formed by the reaction (ii). All of these reactions proceed with third order kinetics, first order in DEM or DEF and second order in CHXA. We propose a kinetic model that allows kinetic constants to be estimated. Furthermore, a numerical solution of the set of differential equations confirms the expected kinetic equations of reactions (i) and (ii) and gives values of rate constants comparable to the estimated ones. A DFT mechanistic study illustrates the structure of the reaction intermediates and transition states of all reactions and explains the contribution of the second amine molecule in the reaction mechanism.

Enhanced corrosion resistance of metal surfaces by film forming amines: A comparative study between cyclohexanamine and 2-(diethylamino)ethanolbased formulations

The use of recycled process water in steam crackers leads to the accumulation of corrosive impurities, hence the need for adequate treatment. Two corrosion inhibitor formulations containing N-[(9Z)−9-octadecen-1-yl]−1,3-propanediamine (N-oleyl-1,3-propanediamine) with either cyclohexanamine (CHA) or 2-(diethylamino)ethanol (DEAE) were compared for their performance. Electrochemical impedance spectroscopy and visual observations showed that the two formulations offered comparable protection against corrosion. Bengal Rose testing and experiments conducted using a quartz-crystal microbalance with dissipation monitoring (QCM-D) indicated that the two formulations yielded similar coverage of the metal surfaces, and that the kinetics of mass adsorption were also similar. QCM-D data further suggested that the films formed with the two formulations had similar rigidity, and contact angle measurements indicated that they formed films with comparable hydrophobicity, which were equally effective in isolating the metal surfaces from water.

Effect of External Electric Field on Inhibition Behavior of Cyclohexylamine Carbonate for Carbon Steel N80 Beneath Adsorbed Thin Electrolyte Layers

Effect of External Electric Field on Inhibition Behavior of Cyclohexylamine Carbonate for Carbon Steel N80 Beneath Adsorbed Thin Electrolyte Layers

Development of Heat-Induced Homogeneous Liquid–Liquid Microextraction for Extraction and Preconcentration of Neonicotinoid Insecticides from Fruit Juice and Vegetable Samples

In this paper, a new version of liquid–liquid microextraction based on heat-induced homogeneous liquid–liquid microextraction has been developed for the extraction and preconcentration of some neonicotinoid insecticides from fruit juice and vegetable samples followed by their determination by high-performance liquid chromatography–diode array detection. In this method, cyclohexyl amine is dissolved in an aqueous solution thermostated at 0 °C. Then, the solution is transferred into a heated water bath. During heating, the solubility of cyclohexyl amine in water is decreased and the produced tiny droplets of the extraction solvent (cyclohexyl amine) are dispersed in whole parts of the solution. The obtained cloudy solution is centrifuged. Finally, an aliquot of the extractant is taken and injected into the separation system for analysis. Various parameters affecting the extraction efficiency such as volume of extraction solvent, temperature, salt addition, and centrifuging rate and time were evaluated. Under the optimum conditions, enrichment factors were obtained in the range of 180–235. The linear ranges of the calibration curves were wide. Limits of detection were in the ranges of 0.38–1.31 and 0.19–0.69 ng mL−1, in vegetable samples and fruit juices, respectively. Limits of quantification were in the ranges of 1.23–4.09 and 0.64–1.15 ng mL−1 in the mentioned samples. Finally, the proposed method was applied to analyze the target analytes in different fruit juice and vegetable samples.

Genome-wide identification and characterization of genes encoding cyclohexylamine degradation in a novel cyclohexylamine-degrading bacterial strain of Pseudomonas plecoglossicida NyZ12

The Gram-negative strain of Pseudomonas plecoglossicida NyZ12 isolated from soil has the ability to degrade cyclohexylamine (CHAM). The genes encoding CHAM degradation by gram-negative bacteria, however, have not been reported previously. In this study, ORFs predicted to encode CHAM degradation by NyZ12 were identified by bioinformatics analysis. Differential expression of the proposed ORFs was analyzed via RNA-seq and quantitative reverse transcription-PCR (qRT-PCR), using RNA extracted from NyZ12 cultured with or without CHAM addition. One CHAM-inducible ORF, RK21_02867 predicted to encode a cyclohexanone monooxygenase (ChnB) was disrupted, as were five ORFs, RK21_00425, RK21_02631, RK21_04207, RK21_04637 and RK21_05539, that had weak homology to the only known cyclohexylamine oxidase (CHAO encoded by chaA) found in Brevibacterium oxydans IH-35A. We also found that a tandem array of five ORFs (RK21_02866-02870) shared homology with those in an operon responsible for oxidation of cyclohexanone to adipic acid, although the ORFs in strain NyZ12 were arranged in a different order with previously found in cyclohexane, cyclohexanol or cyclohexanone degradation strains. The ORFs in this cluster were all up-regulated when CHAM was supplied as the sole carbon source. When one of these five genes, RK21_02867 encoding cyclohexanone (CHnone) monooxygenase, was knocked out, NyZ12 could not grow on CHAM, but it accumulated equimolar amounts of CHnone. Our results show that strain NyZ12 metabolized CHAM directly to CHnone which was then further metabolized to adipate. Despite clearly identifying genes encoding the steps for metabolism of CHAM metabolites, not every one of the putative chaAs was differentially expressed in the presence of CHAM and deletion of each one individually did not completely eliminate the capacity of NyZ12 to degrade CHAM, though it did reduce its growth in several instances. Our results suggest that there is genetic redundancy encoding the initial step in the oxidation of CHAM to CHnone in NyZ12 and that its CHAOs differ considerably from the ChaA, originally described in Brevibacterium oxydans IH-35A.

Unified Synthesis of 1,2-Oxy-aminoarenes via a Bio-inspired Phenol-Amine Coupling

Summary 1,2-Aminophenols and their related nitrogen-containing heterocycles are ubiquitous in medicine, agriculture, and materials science. Here, we describe a bio-inspired and unified approach for their synthesis through a direct, catalytic aerobic coupling of phenols and amines. Key to the formation of the aromatic C–N bond is a facile condensation between the amine and an ortho -quinone, which triggers redox isomerization to an ortho -iminophenol before a series of downstream events. We discuss the factors that govern regioselectivity during aerobic ortho -oxygenation of the phenol and condensation of the amine, and we demonstrate synthetic utility by preparing a structurally diverse family of immunosuppressive heterocycles and the indole alkaloid cephalandole A. Our conditions involve a wide range of simple, un-activated substrates, occur at room temperature with an earth-abundant copper-catalyst and a commercially available diamine ligand, and produce water as the only stoichiometric by-product.

Tuning the properties of segmented polyhydroxyurethanes via chain extender structure

ABSTRACTThe influence of chain extender structure on the properties of segmented polyhydroxyurethane (PHU) was investigated with four diamine molecules: 1,4‐diaminobutane, isophorone diamine, methylene bis(cyclohexyl amine), and bis(aminomethyl) norbornane. These nonisocyanate polyurethanes were synthesized with polytetramethylene oxide‐based soft segment and divinyl benzene dicyclocarbonate (DVBDCC) as hard segment. They were characterized with small‐angle X‐ray scattering (SAXS), dynamic mechanical analysis (DMA), and tensile testing. All PHUs possess nanophase‐separated morphology with interdomain spacings of 12 to 16 nm via SAXS. DMA shows that the nanophase separation is accompanied with broad interphases having a wide range of local compositions. These PHUs exhibit tan δ ≥ 0.30 over broad temperature ranges, indicating their potential as effective damping materials. The flow temperature (Tflow), the temperature range with tan δ ≥ 0.30, and the tensile properties of these PHUs are strongly affected by the molecular structure of the chain extender used in synthesis. At 50 wt % hard‐segment content, values of Tflow, tensile strength, and elongation‐at‐break can be tuned via chain extender from 57 to 105 °C, 1.6 to 22.4 MPa, and 70 to 500%, respectively. Notably, PHU at 50 wt % hard‐segment content, synthesized with norbornane‐based chain extender exhibits the best thermal and mechanical properties with Tflow of 105 °C, tensile strength of 22.4 MPa, elongation‐at‐break of 500%, and tan δ ≥ 0.30 over 74 °C in breadth. By varying hard‐segment content between 30 and 50 wt %, norbornane‐based PHUs afford broad tunability in tensile strength from 0.5 to 22.4 MPa with tan δ ≥ 0.30 spanning temperature range as large as 85 °C. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44942.

Synthesis, characterization, DNA-Binding, enzyme inhibition and antioxidant studies of new N-methylated derivatives of pyridinium amine

A series of novel N-methylated derivatives of pyridinium amine, [L1][Tf]-[L5][Tf], were synthesized and characterized by FTIR, NMR, MS and XRD analyses. Preliminary biological screening of these compounds including antioxidant, enzyme inhibition and DNA (salmon sperm) interaction studies were also carried out. The targeted compounds were synthesized by a melt reaction between 4-chloro-N-methyl pyridinium triflate and corresponding amines (1-naphthyl amine, o-ansidine, 2-nitroaniline, p-ansidine and cyclohexyl amine) at temperature of 230 °C. The DPPH radical antioxidant scavenging activities of these compounds at maximum concentration of 50 μg/mL were observed in the range of 60–70%. Acetylcholine esterase (AChE) and Butylcholine esterase (BChE) inhibitory activities of synthesized compounds at 2 mM concentration were also measured to be at maximum of 79 and 71% respectively. The spectral behavior of ligand-DNA obtained from photo-luminescent measurements showed that all ligands bind with DNA via non-covalent interactions. The binding constant values were determined by UV–visible and fluorescence spectroscopy and were quite close to that obtained from molecular docking studies.

Coupling of homogeneous liquid-liquid extraction and dispersive liquid-liquid microextraction for the extraction and preconcentration of polycyclic aromatic hydrocarbons from aqueous samples followed by GC with flame ionization detection.

In the present study, a simple and rapid method for the extraction and preconcentration of some polycyclic aromatic hydrocarbons in water samples has been developed. In this method, two sample preparation methods were combined to obtain high extraction recoveries and enrichment factors for sensitive analysis of the selected analytes. In the first stage of the method, a homogeneous solution containing an aqueous solution and cyclohexyl amine is broken by the addition of a salt. After centrifugation, the upper collected phase containing the extracted analytes is subjected to the following dispersive liquid-liquid microextraction method. Rapid injection of the mixture of cyclohexyl amine resulted from the first stage and 1,1,2-trichloroethane (as an extraction solvent) into an acetic acid solution is led to form a cloudy solution. After centrifuging, the fine droplets of the extraction solvent are settled down in the bottom of the test tube, and an aliquot of it is analyzed by gas chromatography. Under the optimum extraction conditions, enrichment factors and limits of detection for the studied analytes were obtained in the ranges of 616-752 and 0.08-0.20 μg/L, respectively. The simplicity, high extraction efficiency, short sample preparation time, low cost, and safety demonstrated the efficiency of this method relative to other approaches.

Putrescine and polyamine inhibitors in culture medium alter in vitro rooting response of Decalepis hamiltonii Wight & Arn.

The influence of polyamine putrescine (PUT), and polyamine inhibitors were tested for in vitro rooting response from micro shoots that initially established on Murashige and Skoog (MS) medium comprising 2.7 µM α-Naphthaleneacetic acid (NAA) and 8.9 µM 6-Benzylaminopurine (BA) by using nodal explants of Decalepis hamiltonii. Incorporation of putrescine alone in rooting medium devoid of auxins supported the best response for in vitro rooting qualitatively and quantitatively. Incorporation of putrescine at 50 µM able to induce 8.62 ± 1.93 roots with a maximum root length of 9.10 ± 1.65 cm wherein, the root fresh weight was also found to be high compared to all other treatments (5.248 ± 1.71 g). Addition of putrescine inhibitor cyclohexylamine (CHA) in medium curtailed rooting response from microshoots. Among the three polyamine inhibitors, CHA in presence of 9.8 µM Indole-3-butyric acid (IBA) outperformed α-DL-difluromethylarginine (DFMA) and α-DL-difluoromethylornithine (DFMO) combination with 9.8 µM IBA. The least response for root number (1.55 ± 0.72), root length (1.96 ± 0.45 cm), and root weight (1.94 ± 0.35 g) was found for IBA + PUT + DFMA and the best response was noted for IBA + PUT + CHA (2.6 ± 1.1, 2.92 ± 0.73 cm, 3.03 ± 0.75 g) respectively. Endogenous content of putrescine, spermidine and spermine supported the rooting response from in vitro shoots. These results have clearly demonstrated that putrescine plays a crucial role in rooting of D. hamiltonii. Plantlets were transferred to micro-pots for a short acclimatization stage in greenhouse where they survived at 90 %. This highly reproducible procedure can be adopted for large scale swallow root propagation. Overall, supplementing putrescine in the rooting medium enhances the quantity and quality of roots in D. hamiltonii, thus confirming its role.

Properties of Poly(ether-b-amide)/MMT Composites Prepared with in-situ Polymerized PA12/MMT Nanocomposites

Polyamide12(PA12) 올리고머가 층간에 삽입된 PA12/montmorillonite(MMT) 나노복합체(M-PA)를 4,4"-methylene bis(cyclohexyl amine)과 12-aminododecanoic acid를 이용하여 in-situ 중합으로 합성하였다. 이를 poly(tetramethylene glycol) (PTMG)의 양 말단에 hexamethylene diisocyanate(HDI)로 isocyanate 작용기를 가지도록 합성한 prepolymer와 반응시켜 M-PA 부분과 PTMG 부분이 각각 결정성의 hard segment와 soft segment를 형성하는 poly(ether-bamide)s (PEBA)/MMT 복합체(C-PEBA)를 제조하였다. 결과로서 MMT의 함량이 증가함에 따라 hard segment의 결정용융 엔탈피가 5 wt%까지 증가하다 이후 감소하였고, MMT가 단순 혼합된 같은 구조의 PEBA(B-PEBA)보다 최대신율과 강도가 증가하였으며 3 wt%일 때 최대값를 나타냈다. 영구 변형률은 MMT의 함량이 증가함에 따라 감소하였으며 특히 5 wt% 이상에서는 상업화된 PEBA인 Pebax®나 열가소성 폴리우레탄(TPU)보다 낮거나 비슷한 우수한 탄성성질을 가졌다. PA12/montmorillonite (MMT) nanocomposites (M-PA), polyamide12 (PA12) oligomers intercalated into the crystalline layers of MMT, were synthesized by in-situ polymerization with 4,4"-methylene bis(cyclohexyl amine), 12-aminododecanoic acid, and MMT. Poly(ether-b-amide) (PEBA)/MMT nanocomposites (C-PEBA) consisting of crystalline hard segment and amorphous soft segment from M-PA block and PTMG block repectively were prepared with M-PA and isocyanate terminated poly(tetramethylene glycol) prepolymer by hexamethylene diisocyanate (HDI). As a result, the crystalline melting enthalpy increased up to 5 wt% and then decreased with increasing the MMT content. The maximum strain and strength of the C-PEBA were shown at 3 wt% of MMT content and the values were larger than those of the control PEBA (B-PEBA), simply MMT blended one. However, the permanent setting of C-PEBA decreased with increasing the MMT content, especially at more than 5 wt%, similar to or less than those of Pebax® commercialized PEBA and a typical polyurethane thermoplastic elastomer (TPU).

Theoretical calculations on the mechanism of the elimination kinetics of allyl cyclohexyl-, -amine, -sulfide, -ether, and allyl ethyl ether in the gas phase

The mechanism of the gas-phase elimination allyl cyclohexyl amine, allyl cyclohexyl sulfide, allyl cyclohexyl ether, and allyl ethyl ether has been studied by using ab initio combined methods CBS-QB3, and Density Functional Theory CAM-B3LYP, MPW1PW91, PBE1PBE, M06, and M062X. Products formation is described below: ▪Theoretical calculations of these reactions support the unimolecular process of these gas-phase eliminations. These thermal decompositions undergo a retro-ene type of mechanism and proceed through a non-planar concerted six-membered cyclic transition structure. The energy of activation follow the order allyl ethyl ether (187.0kJ/mol)>N-allyl cyclohexyl amine (171.7kJ/mol)>allyl cyclohexyl ether (170.5kJ/mol)>allyl cyclohexyl sulfide (137.9kJ/mol). The polarization of C5–Z6 bond, and the electronegativity of the heteroatom (O, N) increases the reaction rate compared to allyl ethyl ether. Conversely, the S atom is positively charged and its electronic effect causes a high dissymmetry in the TS geometry, which appear to accelerate the decomposition. The rate determining step of these substrates is the change in hybridization from sp3 to sp2 reflected in the bond order in C3–C4. Calculated kinetic and thermodynamic parameters from the M06/6-311++G(d,p) level of theory are in reasonable good agreement with the experimental values.

Commercial catalysts screening for liquid phase nitrobenzene hydrogenation

In this work, a series of commercially available materials was screened for the catalytic hydrogenation of nitrobenzene (NB). The materials revealed different performances, particularly different activities in what concerns the NB conversion, and notably diverse selectivities towards the industrially desired reaction product, aniline (ANL). The catalysts’ active phases are based on Pd and Ni (respectively groups I and II), namely 1wt.% Pd/Al2O3 (catalyst I.1), 0.3wt.% Pd/Al2O3 (catalyst I.2), 0.3wt.% Pd/Al2O3 (catalyst I.3), and 50wt.% NiO/(Al2O3+SiO2) (catalyst II.1). The fresh and used materials were characterized by several physical-chemical techniques, specifically scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), nitrogen adsorption (with BET surface area determination), X-ray diffraction (XRD), H2 temperature-programmed reduction (TPR), inductively coupled plasma mass spectrometry (ICP-MS) and elemental (CHNS) analysis. It was shown that the catalysts are stable in the conditions studied and no deactivation was found. The characterization results allowed explaining the catalytic behavior of the tested materials. In particular, catalyst I.1 was found to be the less active, probably due to its much lower BET surface area (and larger Pd particle size). On the other hand, catalyst I.2 was the more active, which was well correlated to the smaller average particle size (along with narrower Pd particle size distribution) and smaller pellet size, although the active metal content is low. Finally, it was observed that catalyst II.1 is the most selective towards light by-products (benzene (Bz), cyclohexylamine (CHA), cyclohexanol (CHOL) and cyclohexanone (CHONA)), probably due to its lower pore size dimensions.

Crystal structure of N,N-bis(diphenylphosphanyl)cyclohexylamine, C30H31NP2

Abstract C30H31NP2, monoclinic, P21/n, a = 15.8251(19) Å, b = 10.3667(12) Å, c = 15.900(2) Å, β = 107.225(3)°, V = 2491.5(5) Å3, Z = 4, R gt (F) = 0.0390, wR ref (F 2 ) = 0.0935, T = 163 K.

Reusable Polystyrene-Functionalized Basic Ionic Liquids as Catalysts for Carboxylation of Amines to Disubstituted Ureas

A series of polystyrene (PS)-functionalized basic ionic liquids (BILs) were prepared and used as catalysts for synthesis of disubstituted ureas (DSUs) from amines and carbon dioxide (CO2). The PS-BILs as prepared were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) spectroscopy. For investigating the catalytic activities, all PS-BILs were tested in a model reaction of cyclohexylamine (CHA) and CO2 to synthesize dicyclohexylurea (DCU). Poly-2 having branched [bis-imidazolium]/[bis-bicarbonate] was found to show the highest activity for the DCU formation among all PS-BILs catalysts. For a comparison point of view, ceria (CeO2) as a typical catalyst and original Merrifield’s resin (MR) was also applied for the reaction. Reaction conditions were optimized by varying reaction temperature, pressure, reaction time, and amount of catalyst used. Under optimized conditions, reactions of various amines with CO2 to synthesize the corr...

Telechelic Poly(methyl acrylate)s as Constituents for Multiblock Poly(urethane urea)s

New poly(urethane urea)s based on telechelic poly(methyl acrylate)s (PMAs) and different diisocyanates and diamines are prepared by a two‐step polyaddition process—formation of an isocyanate telechelic prepolymer followed by chain extension with a diamine to form the final poly(urethane urea)s. Hydroxyl‐telechelic or mixed amino‐hydroxyl‐telechelic PMAs are obtained by two different concepts: (i) according to the first concept methyl acrylate (MA) was polymerized by single electron transfer‐living radical polymerization (SET‐LRP) using 2‐hydroxyethyl 2‐bromoisobutyrate as initiator followed by nucleophilic substitution of the halogen end group with n‐butylamine, 2‐methylamino ethanol, or 3‐amino‐1‐propanol and (ii) according to the second concept after SET‐LRP under the same conditions the halogen end group is converted to an azide followed by a click reaction using sodium azide and propargyl alcohol in a one‐pot reaction. Applying the second concept, a hydroxyl‐functional PMA with a share of 83 mol% bifunctionality is obtained. This PMA‐diol is used in polyaddition reaction with different diisocyanates (isophorone diisocyanate (IPDI), 4,4′‐methylenebis(cyclohexyl isocyanate) (HMDI), and 4,4′‐methylenediphenyl diisocyanate (MDI)) resulting in an isocyanate‐telechelic prepolymer followed by chain extension with the corresponding diamines (isophorone diamine (IPDA), 4,4′‐methylenebis(cyclohexyl amine) (HMDA), and 4,4′‐methylenediphenyl diamine (MDA)). The polyurethane based on hydroxyl‐telechelic PMAs and IPDI/IPDA has a molecular weight of Mn = 44 500 g mol−1 and a dispersity Đ = 3.5, respectively; those based on HMDI/HMDA and MDI/MDA have Mn = 24 600 g mol−1 and Đ = 2.2 and Mn = 16 100 g mol−1 and Đ = 2.0, respectively. image