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A three-component Lewis acid-base (Lewis trio) involving a bulky chiral primary amine, B(C6 F5 )3 and a bulky tertiary amine has been developed as an effective enamine catalyst for enantioselective disulfuration reactions. The bulky tertiary amine was found to activate a bulky primary-tertiary diamine-borane Lewis pair for enamine catalysis via frustrated interaction. The resulted chiral bulky Lewis trio (BLT) allows for the construction of chiral disulfides via direct disulfuration with β-ketocarbonyls or α-branched aldehydes in a practical and highly stereocontrolled manner.

The present study analyzes the features of chemical CO2 absorption using tertiary amine solvents by comparing the absorption performance and electrical properties between methyl‐di‐ethanolamine (MDEA) and tri‐ethanolamine (TEA) systems. The results are mostly attributed to the different structures of the two amine molecules. Absorption performance is significantly affected by the molecular structure and water concentration in the amine solution. The absorption performance of the MDEA system is better than that of TEA, which is basically ascribed to the MDEA molecule's more asymmetric and irregular shape than that of TEA, which thus enhances the catalytic activity of MDEA and the reactivity of the −OH moiety in water. The difference of electrical properties such as ionic conductivities (ICs) of the two protonated amines and real ionic activity coefficients (RIAC) between the two systems might be also caused by the different molecular structures of the two amines. The IC of protonated MDEA is estimated to be 23.70% higher than that of protonated TEA, because of the higher ionic mobility and charge density of MDEA. The RIAC of the MDEA system is higher than that of TEA, which is explained by the different physicochemical interactions between the molecules in the two systems. Since water is one of the reactants in the absorption, its concentration in solution significantly affects the results of the systems. In addition, the absorption using tertiary amine is a base‐catalyzed reaction, and thus variations of the overall absorption rate follow a parabolic curve. Therefore, it is maximized to be 14.2 and 9.8 mmol CO2·L−1·min−1 in the 15 wt% MDEA and TEA solutions, respectively. Finally, the correlated equations for in situ estimation of chemical absorption capacity by electrical conductivity measured during the absorption are derived in the two systems. © 2021 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons, Ltd.

Vanadium-based catalysts have shown activity and selectivity in ring-opening metathesis polymerization of strained cyclic olefins comparable to those of Ru, Mo, and W catalysts. However, the application of V alkylidenes in routine organic synthesis is limited. Here, we present the first example of ring-closing olefin metathesis catalyzed by well-defined V chloride alkylidene phosphine complexes. The developed catalysts exhibit tolerance to various functional groups, such as an ether, an ester, a tertiary amide, a tertiary amine, and a sulfonamide. The size and electron-donating properties of the imido group and the phosphine play a crucial role in the stability of active intermediates. Reactions with ethylene and olefins suggest that both 𝛽-hydride elimination of the metallacyclobutene and bimolecular decomposition are responsible for catalyst degradation.

A convenient method for deoxyfluorination of aromatic and aliphatic carboxylic acids with CF3 SO2 OCF3 in the presence of a suitable base at room temperature has been developed. The reaction allows a straightforward access to a variety of acyl fluorides and proves that CF3 SO2 OCF3 is an effective deoxyfluorination reagent for carboxylic acids. The method features simplicity, expeditiousness, high efficiency, ease of handling, good functional group tolerance, a wide range of substrates, excellent yields of products, compatibility of many amine initiators, use of environmentally friendly reagents, and effortless removal of byproducts. This reaction represents the first utilization of trifluoromethyl trifluoromethanesulfonate as a fluorination reagent.

Background Trimethylaminuria (TMAU) (OMIM #602079) is a rare inherited metabolic condition. TMAU is associated with decreased hepatic trimethylamine N‐oxidation, which leads to an excess of the volatile trimethylamine (TMA) instead of substrate conversion to trimethylamine N‐oxide (TMAO). TMA is a tertiary amine derived from the enterobacterial metabolism of precursors such as choline and phosphatidylcholine present in the diet, and is also a bacterial metabolite of TMAO, a normal constituent of saltwater fish. When the involved enzyme flavin mono‐oxygenase 3 is deficient, TMA builds up and is released in the person's sweat, urine, and breath, giving off a strong body odor. We have recently reported the biochemical and genetic characteristics of 13 Irish adult patients with TMAU attending the main Irish Reference Center. Research on the behavioral and psychosocial aspects of this condition is limited. This study explores the patients' perspectives of living with TMAU in Ireland. Methods A qualitative descriptive phenomenological approach was used. Six adults participated in this study. Data were gathered through semi‐structured interviews, which were transcribed and analyzed. Results The results suggest that the participants experienced a negative journey to diagnosis. Fear, anxiety, paranoia, and dysfunctional thinking are a constant struggle. Participants reported using avoidant coping mechanisms and strategic planning to navigate daily life. Conclusion It is considered that the results from this study will inform future interventions with this unique patient cohort.

We report on the characterisation of 16 protic ionic liquids (PILs) prepared by neutralisation of primary or tertiary amines with a range of simple carboxylic acids, or salicylic acid. The extent of proton transfer was greater for simple primary amine ILs compared to tertiary amines. For the latter case, proton transfer was increased by providing a better solvation environment for the ions through the addition of a hydroxyl group, either on the tertiary amine, or by formation of PIL/molecular solvent mixtures. The library of PILs was characterised by differential scanning calorimetry and a range of transport properties (i. e. viscosity, conductivity and diffusivity) were measured. Using the (fractional) Walden rule, the conductivity and viscosity results were analysed with respect to their deviation from ideal behaviour. The validity of the Walden plot for PILs containing ions of varying sizes was also verified for a number of samples by directly measuring self-diffusion coefficients using pulsed-field gradient spin-echo (PGSE) NMR. Ionicity was found to decrease as the alkyl chain length and degree of branching of both the cations and anions was increased. These results aim to develop a better understanding of the relationship between PIL properties and structure, to help design ILs with optimal properties for applications.

To explore the structure-function relationships of cobalt complexes in the catalytic hydrogen evolution reaction (HER), we studied the substitution of a tertiary amine with a softer pyridine group and the inclusion of a conjugated bpy unit in a Co complex with a new pentadentate ligand, 6-[6-(1,1-di-pyridin-2-yl-ethyl)-pyridin-2-ylmethyl]-[2,2']bipyridinyl (Py3Me-Bpy). These modifications resulted in significantly improved stability and activity in both electro- and photocatalytic HER in neutral water. [Co(Py3Me-Bpy)(OH2 )](PF6 )2 catalyzes the electrolytic HER at -1.3 V (vs. SHE) for 20 hours with a turnover number (TON) of 266 300, and photolytic HER for two days with a TON of 15 000 in pH 7 aqueous solutions. The softer ligand scaffold possibly provides increased stability towards the intermediate CoI species. DFT calculations demonstrate that HER occurs through a general electron transfer/proton transfer/electron transfer/proton transfer pathway, with H2 released from the protonation of CoII -H species.

Highly selective recognition of metal ions by rational ligand design is challenging, and simple metal binding by biological ligands is often obscured by nonspecific interactions. In this work, binding-triggered catalysis is used and metal selectivity is greatly increased by increasing the number of metal ions involved, as exemplified in a series of in vitro selected RNA-cleaving DNAzymes. The cleavage junction is modified with a glycyl-histidine-functionalized tertiary amine moiety to provide multiple potential metal coordination sites. DNAzymes that bind 1, 2, and 3 Zn2+ ions, increased their selectivity for Zn2+ over Co2+ ions from approximately 20-, 1000-, to 5000-fold, respectively. This study offers important insights into metal recognition by combining rational ligand design and combinatorial selection, and it provides a set of new DNAzymes with excellent selectivity for Zn2+ ions.

The identification of spiro N-heterocycles as scaffolds that display structural novelty, three-dimensionality, beneficial physicochemical properties, and enable the controlled spatial disposition of substituents has led to a surge of interest in utilizing these compounds in drug discovery programs. Herein, we report the strain-release-driven Friedel-Crafts spirocyclization of azabicyclo[1.1.0]butane-tethered (hetero)aryls for the synthesis of a unique library of azetidine spiro-tetralins. The reaction was discovered to proceed through an unexpected interrupted Friedel-Crafts mechanism, generating a highly complex azabicyclo[2.1.1]hexane scaffold. This dearomatized intermediate, formed exclusively as a single diastereomer, can be subsequently converted to the Friedel-Crafts product upon electrophilic activation of the tertiary amine, or trapped as a Diels-Alder adduct in one-pot. The rapid assembly of molecular complexity demonstrated in these reactions highlights the potential of the strain-release-driven spirocyclization strategy to be utilized in the synthesis of medicinally relevant scaffolds.

The identification of V-type nerve agents poses an analytical challenge. Their spectra obtained by electron ionization mass spectrometry (EI-MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS) are dominated by ions originating from the N,N-dialkylaminoethyl moiety, while ions representative of the alkyl phosphonothiolate part are absent from the spectra or present at negligible abundance. Hence, analogs or isomers with the same amine residue exhibit similar mass spectral patterns, leading to unavoidable ambiguity in their identification.Chemical derivatization was utilized for the structural elucidation of a series of five V-type nerve agents, including O-ethyl S-(2-diisopropylamino)ethyl methylalkyl phosphonothiolate (VX), O-isobutyl S-(2-diethylamino)ethyl methylalkyl phosphonothiolate (RVX) and O-ethyl S-(2-diethylamino)ethyl methylalkyl phosphonothiolate (VM). The procedure consisted of "in-vial" oxidation of the tertiary amine group with 3-chloroperbenzoic acid (m-CPBA) at ambient temperature followed by liquid chromatography (LC)/Orbitrap-ESI-MS/MS analysis with no other sample preparation.The generated N-oxide of the V-type nerve agents altered the charge distribution occurring during fragmentation and produced informative ESI-MS/MS spectra characteristic of the alkyl phosphonothiolate structure, enabling a higher degree of certainty in their identification. Moreover, two VX isomers possessing an identical tertiary amine moiety that coeluted at practically the same retention time and displayed high mass spectral similarity were easily differentiated, and their structures elucidated once derivatized.In contrast to the ESI-MS/MS spectra of the V-type nerve agents, which exhibited mostly/only information on the amine-containing residue, the ESI-MS/MS spectra of the V-type nerve agent N-oxides revealed ions indicative of both the alkyl phosphonothiolate and the amine parts, enabling their reliable structural elucidation.

Acatalyst-driven one-pot reaction sequence is developed for the enantio- and diastereoselective synthesis of tetrasubstituted cyclohexenes from simple unsaturated ketones or thioesters.The method involves atertiary amine/squara- mide-catalyzed a-selective addition of transiently generated trienolates to nitroolefins,subsequent base-catalyzed double bond isomerization, and an intramolecular (vinylogous) 1,6- addition reaction, arare key carbocyclization step that proceeded with essentially perfect stereocontrol Support has been provided by the University of the Basque Country UPV/EHU (UFI QOSYC 11/22), the Basque Government (GV grant No IT-1236-19), and the Ministerio de Economía y Competitividad (MEC Grant CTQ2016-78487-C2), Spain. I.I. and O.O. thank GV for a fellowship. G.Z. and E.G.-B thank the European Funding Horizon 2020-MSCA (ITN-EJD CATMEC 14/06-721223).

Tetrahydroisoquinolines are found in many natural products and drug compounds and a convenient method to access 1‐substituted derivatives is to carry out the lithiation at C‐1 followed by trapping with an electrophile. Here we explore the feasibility of lithiation at C‐3 by using a substrate with a benzylic proton on both sides of the nitrogen atom such that lithiation with nBuLi could occur at either C‐1 or C‐3 of the tetrahydroisoquinoline. The regioselectivity in the lithiation was determined using the substrate N‐tert‐butoxycarbonyl (Boc)‐3‐phenyltetrahydroisoquinoline. The lithiation could be followed by in situ ReactIR spectroscopy and the rate of rotation of the carbamate group was determined (barrier to rotation was approximately ΔG‡ 58 kJ/mol at –50 °C). Subsequent trapping of the organolithium species with an electrophile gave a mixture of two regioisomeric products with a preference for reaction at C‐1. This led to the isolation of 1,3‐disubstituted tetrahydroisoquinolines with trans relative stereochemistry. Removal of the Boc group from the nitrogen atom gave secondary and tertiary amine products.

An unprecendented chiral sulfide catalyzed desymmetrizing enantioselective chlorination is disclosed. Various aryl-tethered diolefins and diaryl-tethered olefins afforded teralins and tricyclic hexahydrophenalene derivatives, respectively, bearing multiple stereogenic centers in high yields with excellent enantio- and diastereoselectivities. In contrast, the tertiary amine catalyst (DHQD)2 PHAL led to a diastereomeric product. The products could be transformed into a variety of compounds, such as spiro-N-heterocycles.

Derivatization reactions are commonly used in mass spectrometry to improve analyte signals, specifically by enhancing the ionization efficiency of those compounds. Vicinal diols are one group of biologically important compounds that have been commonly derivatized using boronic acid. In this study, a boronic acid with a tertiary amine was adapted for the derivatization of vicinal diol metabolites in B73 maize tissue cross-sections for mass spectrometry imaging analysis. Using this method, dozens of vicinal diol metabolites were derivatized, effectively improving the signal of those metabolites. Many of these metabolites were tentatively assigned using high-resolution accurate mass measurements. In addition, reaction interference and cross-reactivity with various other functional groups were systematically studied to verify data interpretation.

Carbon dioxide capture using tertiary amines in ethylene glycol solvent was performed under ambient conditions. Subsequently, the CO2 captured as alkyl carbonate salts was successfully hydrogenated to methanol, in the presence of H2 gas and Ru-Macho-BH catalyst. A comprehensive series of tertiary amines were selected for the integrated capture and conversion process. While most of these amines were effective for CO2 capture, tetramethylethylenediamine (TMEDA) and tetramethylbutanediamine (TMBDA) provided the best CH3 OH yields. Deactivation of the base due to side reactions was significantly minimized and substantial base regeneration was observed. The proposed system was also highly efficient for CO2 capture from a gas mixture containing 10 % CO2 , as found in flue gases, followed by tandem conversion to CH3 OH. We postulate that such high boiling tertiary amine-glycol systems as dual capture and hydrogenation solvents are promising for the realization of a sustainable and carbon-neutral methanol economy in a scalable process.

The coordination chemistry of the hexadentate bispidine ligand L1 with three pyridine, one pyridazine, and two tertiary amine donors with CuII and ZnII is reported. The substitution of one of the two cis-disposed pyridine donors in-plane with the two tertiary amines of the bispidine backbone by a pyridazine group was predicted to substantially reduce distortion from planarity of the tetradentate subunit and therefore was assumed to lead to higher CuII complex stability. The X-ray single-crystal structures of the ZnII and CuII complexes, which are in excellent agreement with the DFT- and MM-optimized structures, confirmed this prediction but indicated that deviation from planarity is appreciable. This also emerges from solution spectroscopy (UV/Vis/NIR and EPR of the CuII complex), which indicated that the in-plane ligand field is only slightly increased. The geometric parameters together with the lower basicity of pyridazine versus pyridine (pKa =2.33 vs. 5.23) are also in agreement with an only slightly more negative redox potential of the CuII/I couple (Eo =-780 vs. -760 mV, MeCN, vs. Fc/Fc+ ), and the potentiometrically determined CuII stability constant with L1 is slightly lower than that with the parent ligand L2 (log K=12.7 vs. 14.5). Therefore, modification of the donor groups is a more promising approach to increasing the stabilities of these complexes and yields 64 CuII chelators that outperform known hexadentate bispidine ligands.

Water compatibility for heterogeneous photocatalysts has been pursued for energy and environmental applications. However, there exists a trade-off between hydrophilicity and recyclability of the photocatalyst. Herein, we report a conjugated polymer photocatalyst with tertiary amine terminals that reversibly binds CO2 in water, thereby generating switchable hydrophilicity. The CO2 -assisted hydrophilicity boosted the photocatalytic efficiency in aqueous medium with minimum dosage. When CO2 was desorbed, the photocatalyst could be simply regenerated from reaction media, facilitating the repeated use of photocatalyst. Hydrophilicity/hydrophobicity control of the polymer photocatalyst was successfully showcased through a variety of organic photoredox reactions under visible-light irradiation in water.

Thermoresponsive polymers exhibiting unique reversible phase transition properties in aqueous solution in response to temperature stimuli have been extensively investigated. In the past two decades, thermoresponsive polymers based on tertiary amine moieties have achieved considerable progress and become an important family of thermoresponsive polymers, including tertiary amine functionalized poly((meth)acrylamide)s, poly((meth)acrylate)s, poly(styrene)s, poly(vinyl alcohol)s, and poly(ethylene oxide)s, which exhibit lower critical solution temperature and/or upper critical solution temperature in water or aliphatic alcohols. Their phase transition behavior can be modulated by the solution pH and CO2 due to the protonation of tertiary amine moieties in acidic condition and deprotonation in alkaline condition and the charged ammonium bicarbonate formed by the tertiary amine moieties and CO2 . The aim of this review is to summarize the recent progress in the thermoresponsive polymers based on tertiary amine moieties.

A type of switchable tertiary amine Gemini surfactant, N,N′-di(N,N-dimethyl propylamine)-N,N′-didodecyl ethylenediamine, was synthesized by two substitution reactions with 3-chloro-1-(N,N-dimethyl) propylamine, bromododecane and ethylene diamine as main raw materials. The structure of the product was characterized by FTIR and 1H-NMR. We also investigated the surface tension when CO2 was bubbled in different concentrations of surfactant solution and the influence of different CO2 volumes on surface tension under a constant surfactant concentration. Finally the surface tension curve and the related parameters were acquired by surface tension measurements. The experimental results showed that the structure of the synthesized compounds were in conformity with the expected structure of the surfactant, and displayed a better surface activity after bubbling CO2. The critical micelle concentration (CMC) surface tension at CMC (γ cmc) pC20 (negative logarithm of the surfactant’s molar concentration C20, required to reduce the surface tension by 20 mN/m) surface excess (Γ max) at air/solution interface and the minimum area per surfactant molecule at the air/solution interface (A min) were determined. Results indicate that the target product had good surface activity after bubbling CO2.

A divergent synthesis of optically active quaternary Δ4 - and Δ5 -dehydro prolines is developed based on the first catalytic enantioselective conjugate addition of α-substituted isocyano(thio)acetates to vinyl ketones that is general for both α-aryl and α-alkyl isocyano(thio)acetates. The new tetrasubstituted C-N stereocenter is formed without the need of any metal salt due to a bifunctional tertiary amine/squaramide catalyst, featuring a bulky polyaryl sidearm and an unusually short squaramide diamide H⋅⋅⋅H interatomic distance in the solid state.

Polyacrylonitrile fibers were functionalized with different amines to construct special tridimensional catalytic microenvironments at the surface. The polarity of the microenvironments at the surface of the fiber catalyst was tuned by changing the ratio of hydrophobic and hydrophilic amines. The catalytic performances of these microenvironments were examined for a cyanation reaction in water. Among these fiber catalysts with different microenvironments, the one modified with more hydrophobic benzylamine groups (PANBTF) shows much higher catalytic activity than that modified by hydrophilic ethanolamine groups. PANBTF can efficiently and rapidly catalyze the cyanation reaction of benzaldehyde and ethyl cyanoformate in water with a yield of 94 % at room temperature within 40 min. Moreover, a mechanism promoted by the hydrophobic microenvironment has been proposed to explain the high and specific catalytic activity of PANBTF. In addition, this fiber catalyst exhibited excellent recyclability and reusability (8 times) without further treatment, and it also performed well in flow-chemistry tests and scaled-up experiments, which indicated potential for the application of PANBTF in industrial production.

In this study, an oxidized starch (OS)/montmorillonite (MMT) nanocomposite was prepared via a solution intercalation method. Before incorporating MMT into OS, MMT was organically modified with 20 wt% of octadecyl dimethyl tertiary amine followed by a hydrophilic ball-milling treatment in the presence of urea, ethanol, and formaldehyde (two-step processing technique). X-ray diffraction revealed that the interlayer spacing of the MMT expanded from 1.29 to 2.00 nm after the organic modification and MMT turned into an exfoliated state after the hydrophilic treatment and the solution intercalation, which was also confirmed by transmission electron microscope result. Owing to the interaction between OS and the silicate layers, the hygroscopicity of the obtained nanocomposite decreased and the mechanical properties were improved. Our work demonstrates that the two-step processing technique is a promising method for modifying MMT nanofillers and preparing starch/MMT nanocomposites, which paves a way for preparing other polar polymer-based nanocomposites and developing environment-friendly textile sizing materials. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers

CO2 absorption into aqueous solutions of two tertiary alkanolamines, namely, MDEA and DMEA with and without carbonic anhydrase (CA) was investigated with the use of the stopped-flow technique at temperatures in the range of 293–313 K, CA concentration varying from 0 to 100 g/m3 in aqueous MDEA solution with the amine concentration ranging from 0.1 to 0.5 kmol/m3, and CA concentration varying from 0 to 40 g/m3 in aqueous DMEA solution with the amine concentration ranging from 0.05 to 0.25 kmol/m3. The results show that the pseudofirst-order reaction rate (k0, amine; s−1) is significantly enhanced in the presence of CA as compared with that without CA. The enhanced values of the kinetic constant in the presence of CA has been calculated and a new kinetics model for reaction of CO2 absorption into aqueous tertiary alkanolamine solutions catalyzed by CA has been established and used to make comparisons of experimental and calculated pseudo first-order reaction rate constant (k0, with CA) in CO2-MDEA-H2O and CO2-DMEA-H2O solutions. The AADs were 15.21 and 15.17%, respectively. The effect of pKa on the CA activities has also been studied by comparison of CA activities in different tertiary amine solutions, namely, TEA, MDEA, DMEA, and DEEA. The pKa trend for amines were: DEEA > DMEA > MDEA > TEA. In contrast, the catalyst enhancement in amines was in the order: TEA> MDEA> DMEA> DEEA. Therefore, it can be seen that the catalyst enhancement in the amines decreased with their increasing pKa values. © 2017 American Institute of Chemical Engineers AIChE J, 2017

The surface of mesoporous silica was modified with a Pd–bisphosphine complex and/or a tertiary amine group for concerted acceleration of allylation reactions. Mesoporous-silica-supported catalysts with a 1.6 nm pore diameter showed higher performance than nonporous or larger mesoporous silica-supported catalysts owing to the accumulation of active sites into a confined space. For the case in which allyl alcohol was used in the reaction, the presence of a silanol group on the surface was quite effective: the turnover number of Pd was nine times greater than that of the homogeneous Pd complex.

Self-reinforcement gel-like halloysite nanotube (g-HNT) hybrids with various viscoelastic behaviors were fabricated by firstly treating with various concentrations of sodium hydroxide (NaOH) solution and then grafting tertiary amine and ion-exchange reacting with sulfonate anions. The morphology, composition, thermal stability and rheological behavior of the g-HNT hybrids were systematically characterized and analyzed using various methods. It is found that the viscoelasticity of g-HNT hybrids can be easily regulated by using different NaOH solution-treated HNTs as inorganic core and temperatures. In addition, the g-HNT hybrids treated with medium concentration of NaOH (0.06 mol L−1) have the lowest viscosity and highest level of dispersion compared with those treated with other concentrations of NaOH solution. Due to the amphiphilic nature of g-HNT hybrids and their lower viscosity than HNT powder, as novel hybrid fillers, they were utilized to prepare polystyrene composites by direct melt blending for achieving simultaneous reinforcement and plasticization effects. Besides the above mentioned advantages, the thermal conductivity of polystyrene composites is also surprisingly improved by reducing the interfacial mismatch between the filler and polymer matrix. The solvent-free and self-reinforcement hybrids provide a convenient and green path for fabricating high-performance polymer composites. © 2017 Society of Chemical Industry

A series of tertiary aminosquaramides as bifunctional organocatalysts in the ring-opening polymerization (ROP) of l-lactide (l-LA) were developed, allowing the activation of both the l-LA monomer and the alcohol group of the initiator/propagating species. Further, the impact of tertiary nitrogen substituents on catalytic activity in ROP of l-LA was explored. The tertiary aminosquaramide— an air-stable and moisture-stable catalyst—exhibited superior activity in contest with thiourea counterpart when both were equipped with a similar tertiary amine group. Kinetic and chain-extension experiments indicated that the formed poly(l-LA) is featured with narrow polydispersity and high end-group fidelity, hallmarks of a living polymerization process. The initiator efficiency was further executed at ease by preparation of an ABA triblock copolymer poly (l-LA)-b-poly (ethylene glycol)-b-poly (l-LA) in the presence of a dual-headed PEG macroinitiator. 1H NMR titration experiments suggested a bifunctional catalytic mechanism, wherein both the l-LA monomer and the propagating hydroxyl group were activated en route to polymerization. The 1H NMR, SEC, and MALDI-TOF MS measurements validated the quantitative incorporation of the initiator in the polymeric chains and enchainment over competitive trans-esterification reaction. Overall, the structure-activity relationships were surveyed to uncover aminosquaramide as a new bifunctional dual hydrogen-bond donor catalyst for living ROP of l-LA. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017

To favor the curing process of epoxy resin by cross-linking and not by vitrification, the use of a tertiary amine salt is proposed. The curing reaction between diglycidyl ether of bisphenol A and tris-(dimethylaminomethyl) phenol tri(2-ethyl hexanoate) is studied by differential scanning calorimetry (DSC). Studies are carried out at different concentrations of amine salt: 5, 7.5, and 10 wt%. The vitrification is observed at low concentrations of the amine salt in curing experimental assessments. Furthermore, the experimental characterization of the glass transition temperature at different amine salt concentration allows inferring the polymer network connectivity. Later, the Kissinger method is used to calculate the activation energy. Finally, a reaction mechanism between the epoxy resin and the curing agent is proposed. The reaction mechanism is based on four reactions that may occur. In the most likely reaction happening in the curing, the 2-ethyl hexanoate behaves as a catalyst through three types of esterification. The characterization and mechanism of the curing reaction of the epoxy resin DER 331 and the amine salt tris-(dimethylaminomethyl) phenol tri(2-ethyl hexanoate) have not been reported previously, so it is a novel support of technological relevance for the cure of epoxy community. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers

CO2 -induced switchable tertiary amine-based organocatalysts were investigated for an efficient catalyst and product separation by its different partitioning between an organic and carbonated water phase. In this case study, the switching ability of eight tertiary amine-based catalysts between the organic and water phase by addition or removal of CO2 was investigated. Here, the catalyst switched both nearly completely (99.9 %) into the aqueous phase by addition of CO2 and effectively back into the organic phase (99.3 %) by expelling CO2 . With this technique, the organocatalyst was successfully recovered and reused twelve times without significant loss of activity (up to 90 % enantiomeric excess) for the asymmetric nitroaldol (Henry) reaction. After the first catalyst switch, evaporation of the solvent affords the product in 98 % purity without any further purification steps.

A novel hydroxy-, methoxy-, and phenoxy-bridge “Mitsubishi emblem” tetranuclear aluminum complex (1) is synthesized from an unsymmetric amine-pyridine-bis(phenol) N2O2-ligand (H2L1) and a symmetric amine-tris(phenol) NO3-ligand (H2L2). Two same configuration chiral nitrogen atoms are formed in the tetranuclear Al complex upon coordination of the unsymmetric tertiary amine ligand to central Al. Complex 1 initiates controlled ring-opening polymerization (ROP) of rac-lactide and afford polylactide (PLA) with narrow molecular weight distributions (Mw/Mn = 1.05–1.19). The analysis of 1H NMR spectra of the oligomer indicates that the methoxy group is the initiating group and the ring-opening polymerization of lactide follows a coordination-insertion mechanism. The Homonuclear decoupled 1H NMR spectroscopy suggests the isotactic-rich chains is preferentially formed in PLA. The study on kinetics of the ROP of lactide reveals the homopropagation rate is higher than the cross-propagation rate, which is in agreement with the observed isotactic selectivity in the ROP of rac-lactide. The stereochemistry of the polymerization was also supported by activation parameters. The introduction of unsymmetric ligand H2L1 has an effect on stereoslectivity of polymerization. This result may be of interest for the design of multinuclear metal complex catalysts containing functionalized ligands. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017

Solid absorbents made with polyethylenimine (PEI), which is loaded on different porous substrates, are promising for postcombustion carbon dioxide capture. Herein, theoretical studies of polyamine applications, including PEI for carbon dioxide capture, are reviewed and the development of experimental work on carbon dioxide capture by using PEI summarized. The mechanisms of carbon dioxide capture are discussed at different reaction sites of the polyamines, such as primary, secondary, and tertiary amine groups. Experimental achievements in carbon dioxide capture are investigated by the incorporation of PEI with different support materials, such as mesoporous silica; nanotubes; membranes; and other materials, such as alumina, zeolite, resin, metal–organic frameworks, and glass fibers, through impregnation, grafting, and synthesis. The excellent carbon dioxide capture capacity and great stability of PEI-impregnated nanomaterials highlight PEI as one of the greatest candidates for carbon dioxide capture from flue gas or air.

In this work, the equilibrium CO2 solubility in the aqueous tertiary amine, N-methyl-4-piperidinol (MPDL) was measured over a range of temperatures, CO2 partial pressures and amine concentrations. The dissociation constant of the MPDL solution was determined as well. A new thermodynamic model was developed to predict the equilibrium CO2 solubility in the MPDL-H2O-CO2 system. This model, equipped with the correction factor (Cf), can give reasonable prediction with an average absolute deviation of 2.0%, and performs better than other models (i.e., KE model, Li-Shen model, and Hu-Chakma). The second-order reaction rate constant (k2) of MPDL and the heat of CO2 absorption (–ΔHabs) into aqueous MPDL solutions were evaluated as well. Based on the comparison with some conventional amines, MPDL revealed a high-equilibrium CO2 loading, reasonably fast absorption rate when compared with other tertiary amines, and a low energy requirement for regeneration. It may, therefore, be considered to be an alternative solvent for CO2 capture. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3395–3403, 2017

Fluoroalkylation reagents based on hypervalent iodine are widely used to transfer fluoroalkyl moieties to various nucleophiles. However, the transferred groups have so far been limited to simple structural motifs. We herein report a reagent featuring a secondary amine that can be converted to amide, sulfonamide, and tertiary amine derivatives in one step. The resulting reagents bear manifold functional groups, many of which would not be compatible with the original synthetic pathway. Exploiting this structural versatility and the known high reactivity toward thiols, the new-generation reagents were used in bioconjugation with an artificial retro-aldolase, containing an exposed cysteine and a reactive catalytic lysine. Whereas commercial reagents based on maleimide and iodoacetamide labeled both sites, the iodanes exclusively modified the cysteine residue. The study thus demonstrates that modular fluoroalkylation reagents can be used as tools for cysteine-selective bioconjugation.

Functionalization of the aromatic core of naphthalene diimide (NDI) chromophores with morpholine substituents leads to molecules with strong absorbance in the visible spectrum. The shift of absorption maxima to lower energy is determined not only by the degree of substitution but also by the relative conformation and orientation of the tertiary amine with respect to the plane of the NDI.

Reported herein is the first example of 2-allylazaarenes in asymmetric catalysis. Highly γ-selective allylation was demonstrated for activated ketones, including isatins and trifluoromethyl ketones. In the presence of either an amino-acid-based tertiary amine or quaternary ammonium salt catalyst, two series of tertiary hydroxy-containing moieties were installed at the remote δ-position of azaarenes in good chemical yields, excellent enantioselectivities, and E/Z ratios. The success of current γ-selective reactions should provide inspiration for expansion to other allylazaarene derivatives and would open up new paradigms for the synthesis of chiral γ- and/or δ-functionalized azaarenes.