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In the hydrated complex salt, [Ni(C9H14N2)2(H2O)2]Cl2•2H2O, the asymmetric unit comprises of half of the complex cation along with one chloride anion and one non-coordinating water molecule. The central nickel(II) atom is located on an inversion center and is coordinated in a trans octahedral fashion by four N atoms from two bidentate 1,2-diamino-1-phenylpropane ligands in the equatorial plane, and by two oxygen atoms from two water molecules occupying the axial sites. The five-membered chelate ring is in a slightly twisted envelope conformation. The crystal packing features O--H• • •Cl, N--H• • •O and N--H• • •Cl hydrogen bonds. Hirshfeld surface analysis revealed that the most important contributions to the crystal packing are from H• • •H (56.4%), O• • •H/ H• • •O (16.4%) and H• • •Cl (13.3%) interactions. The crystal void volume was calculated to be 15.17%. [ABSTRACT FROM AUTHOR]

The reaction of isoalantolactone with primary amines or piperazine proceeds under mild conditions with high stereoselectivity to give 11,13-isoalantolactone dimers connected by an alkyldiamine or piperazine linker. The reaction of isoalantolactone with propargylamine hydrochloride afforded the corresponding 13-propargylamino-11,13-dihydroisoalantolactone or 13-propargylamino-N-bis(11,13-dihydroisoalantolactone). The synthesized propargylamines showed high activity in the Cu-catalyzed cycloaddition with organic azides. The newly synthesized compounds with a bis-eudesman structure were found to exhibit antibacterial activity against strains of Staphylococcus aureus, Bacillus cereus, and Escherichia coli. [ABSTRACT FROM AUTHOR]

In this work, CO2 equilibrium solubility of 1M N,N‐diethylethanolamine (DEEA):2M 1,6‐hexamethyl diamine (HMDA), 1.5M DEEA:1.5M HMDA and 2M DEEA:1M HMDA was studied with a temperature range of 298–333 K and CO2 partial pressure range of 8–100 kPa. Seven thermodynamic models including Empirical model, Kent and Eisenberg (KE) model, Hu–Chakma model, Austgen model, Helei Liu model, Liu et al. model, and Li–Shen model were developed by correlating reaction equilibrium constants with observed equilibrium solubility of CO2 in mixed amine solvents. The evaluation of those models was conducted in terms of the average absolute relative deviation (AARD). The results indicated that Liu et al. model considering T, [Amine], Ptotal and [CO2(aq)] can better represent this complex system with an AARD of 8.06%. Meanwhile, comprehensive comparison and analysis were also performed to identify the contribution of parameters to develop models, which could provide a guideline for the development of accurate thermodynamic models for representation of thermodynamic behaviors. [ABSTRACT FROM AUTHOR]

Background Dental caries is one of the most prevalent diseases, and treating carious lesions remains a major concern, especially in pediatric dentistry. Minimally invasive interventions have been proposed as a promising treatment modality for caries control. Aim This study evaluated nano silver fluoride versus silver diamine fluoride with potassium iodide for the treatment of carious dentine in primary teeth. Material and methods This in vivo study was performed on 30 children presented with 60 primary molars with soft dentinal lesions. Carious teeth were assigned into two equal groups: group I received silver diamine fluoride with potassium iodide, while group II received nano silver fluoride. Teeth were diagnosed and treated at the baseline visit and followed up for clinical evaluation at 3, 6, and 9 months. Also, dentine samples were obtained from the initial carious teeth and after 9 months of applying the treatments for microbiological evaluation. Results Both groups had comparable clinical values at 3, 6, and 9 months, with no statistically significant difference. While after 9 months, there was a highly significant increase in the number of teeth showing dentine color change in group I compared with group II. Microbiological results showed no significant difference in the reduction of Lactobacillus count between both groups. While there was a significant difference between both groups in terms of Streptococcus mutans count. Conclusion Silver diamine fluoride with potassium iodide and nano silver fluoride provides simple and effective dentinal caries management. [ABSTRACT FROM AUTHOR]

Fifty complexes of the type [RR’SeL1-10] (where, R=R’= CH3 ; n-C4H9 ; n-C8H17; i-C3H7 and C6H5 and L = Macrocyclic Ligand derived from 2,6-diformylpyridine and aliphatic diamines condensation) have been synthesized and characterized by molar conductivity method, elemental analysis, infrared spectroscopy and X-ray Photoelectron Spectroscopy. A distorted octahedral geometry was established for each [RR’SeL1-10] complexes. [ABSTRACT FROM AUTHOR]

Enantiomerically pure (S)-1-phenylethan-1-amine has been applied in Mannich-type condensation between formaldehyde and naphthalenediols leading to the synthesis of chiral bis-dihydro[1,3]naphthoxazines in excellent yields. Salen-type structures have been synthesized, applying R,R- or S,S-cyclohexane-1,2-diamines in condensation with formaldehyde and naphthalene-2-ol. The obtained chiral imidazolidine derivatives of the type 1,1′-(((3a,7a)-hexahydro-1H-benzo[d]imidazole-1,3(2H)diyl)bis(methylene))bis(naphthalen-2-ol) were evaluated as pre-catalysts for the addition of diethyl zinc to aldehydes. The structures of the newly synthesized compounds were elucidated using 1D and 2D NMR experiments (COSY, HMBC, HSQS), elemental analysis, mass spectrometry (HRMS spectra) and single-crystal X-ray diffraction (SCXRD). The products were further characterized with powder X-ray diffraction (PXRD) and thermal analysis (DSC). [ABSTRACT FROM AUTHOR]

Background: Greenhouse gases, especially CO2, are primary factors for global warming and CO2 emissions continue to increase annually. Many legislations and agreements have been made to decrease, or at least stabilize, CO2 concentrations in the atmosphere. Moreover, promising CO2 capture technologies, such as adsorption using solid sorbents, have been developed and shown high CO2 adsorption capacity. Results: Volcanic tuff, a natural pozzolanic material, was evaluated as a solid CO2 adsorbent in this study. Following pre‐treatment of the volcanic tuff with HCl solution, CO2 adsorption experiments were conducted by thermogravimetric analysis (TGA). Diamine functionalization of the volcanic tuff was carried out using amine based compounds with different chain lengths, including ethylenediamine, 1,4‐diaminobutane and 1,6‐diaminohexane. The CO2 adsorption capacity of the volcanic tuff was significantly enhanced in the presence of 1,6‐diaminohexane. Maximum CO2 adsorption capacity was determined to be 42.94 mg g−1 with 70 wt% 1,6‐diaminohexane loading. The CO2 adsorption capacity of the 1,6‐diaminohexane functionalized volcanic tuff decreased with increasing temperature, which was an indication of exothermic adsorption. Adsorption–desorption cycles revealed that the 1,6‐diaminohexane functionalized volcanic tuff was a reusable CO2 adsorbent with high stability. Conclusion: The results show that the low cost, eco‐friendly, and highly stable diamine functionalized volcanic tuff can be considered a promising adsorbent for CO2 capture. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

This study aims to advance the field of green chemistry and catalysis by exploring alternatives to conventional non-renewable energy sources. Emphasis is placed on hydrogen as a potential fuel, with a focus on the catalytic properties of Ni(II) complexes when coordinated with o-phenylenediamine and diimine ligands. We report the synthesis and comprehensive characterization, with various physical and spectroscopic techniques, of three heteroleptic Ni(II) complexes: [Ni(1,10-phenanthroline)(o-phenylene diamine)] (1), [Ni(2,2-dimethyl-2,2-bipyridine)(o-phenylene diamine)] (2), and [Ni(5,5-dimethyl-2,2-bipyridine)(o-phenylene diamine)] (3). The catalytic activity of these complexes for hydrogen evolution was assessed through photochemical studies utilizing visible light irradiation. Two distinct photosensitizers, fluorescein and quantum dots, were examined under diverse conditions. Additionally, their electrocatalytic behavior was investigated to elucidate the hydrogen evolution reaction (HER) mechanism, revealing a combined proton-coupled electron transfer (PCET)/electron-coupled proton transfer (ECPT) mechanism attributed to the chemical nature of the diamine ligand. The influence of ligand substituent position, ligand chemical nature, and photosensitizer type on catalytic performance was systematically studied. Among the complexes investigated, complex 2 demonstrated superior catalytic performance, achieving a turnover number (TON) of 3357 in photochemical experiments using fluorescein as a photosensitizer. Conversely, complex 1 exhibited the highest TON of 30,066 for HER when quantum dots were employed as the photosensitizer.

Carbon capture at fossil fuel-fired power plants is a critical strategy to mitigate anthropogenic contributions to global warming, but widespread deployment of this technology is hindered by a lack of energy-efficient materials that can be optimized for CO2 capture from a specific flue gas. As a result of their tunable, step-shaped CO2 adsorption profiles, diamine-functionalized metal-organic frameworks (MOFs) of the form diamine-Mg2(dobpdc) (dobpdc4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) are among the most promising materials for carbon capture applications. Here, we present a detailed investigation of dmen-Mg2(dobpdc) (dmen = 1,2-diamino-2-methylpropane), one of only two MOFs with an adsorption step near the optimal pressure for CO2 capture from coal flue gas. While prior characterization suggested that this material only adsorbs CO2 to half capacity (0.5 CO2 per diamine) at 1 bar, we show that the half-capacity state is actually a metastable intermediate. Under appropriate conditions, the MOF adsorbs CO2 to full capacity, but conversion from the half-capacity structure happens on a very slow time scale, rendering it inaccessible in traditional adsorption measurements. Data from solid-state magic angle spinning nuclear magnetic resonance spectroscopy, coupled with van der Waals-corrected density functional theory, indicate that ammonium carbamate chains formed at half capacity and full capacity adopt opposing configurations, and the need to convert between these states likely dictates the sluggish post-half-capacity uptake. By use of the more symmetric parent framework Mg2(pc-dobpdc) (pc-dobpdc4- = 3,3'-dioxidobiphenyl-4,4'-dicarboxylate), the metastable trap can be avoided and the full CO2 capacity of dmen-Mg2(pc-dobpdc) accessed under conditions relevant for carbon capture from coal-fired power plants.

PurposeLower grade gliomas (LGGs) are malignant brain tumors. Current therapy is associated with short- and long-term toxicity. Progression to higher tumor grade is associated with contrast enhancement on MRI. The majority of LGGs harbor mutations in the genes encoding isocitrate dehydrogenase 1 or 2 (IDH1/IDH2). Vorasidenib (AG-881) is a first-in-class, brain-penetrant, dual inhibitor of the mutant IDH1 and mutant IDH2 enzymes.Patients and methodsWe conducted a multicenter, open-label, phase I, dose-escalation study of vorasidenib in 93 patients with mutant IDH1/2 (mIDH1/2) solid tumors, including 52 patients with glioma that had recurred or progressed following standard therapy. Vorasidenib was administered orally, once daily, in 28-day cycles until progression or unacceptable toxicity. Enrollment is complete; this trial is registered with ClinicalTrials.gov, NCT02481154.ResultsVorasidenib showed a favorable safety profile in the glioma cohort. Dose-limiting toxicities of elevated transaminases occurred at doses ≥100 mg and were reversible. The protocol-defined objective response rate per Response Assessment in Neuro-Oncology criteria for LGG in patients with nonenhancing glioma was 18% (one partial response, three minor responses). The median progression-free survival was 36.8 months [95% confidence interval (CI), 11.2-40.8] for patients with nonenhancing glioma and 3.6 months (95% CI, 1.8-6.5) for patients with enhancing glioma. Exploratory evaluation of tumor volumes in patients with nonenhancing glioma showed sustained tumor shrinkage in multiple patients.ConclusionsVorasidenib was well tolerated and showed preliminary antitumor activity in patients with recurrent or progressive nonenhancing mIDH LGG.

A series of viscosity probes targeting different organelles were obtained using a single hemicyanine dye as the matrix structure. Specifically, probes 1a–d were obtained by introducing four amines (6-amino-2H-chromen-2-one, N-(2-aminoethyl)-4-methylbenzenesulfonamide, dodecan-1-amine and N,N diphenylbenzene-1,4-diamine) into the indole hemicyanine dye of the carboxylic acid with a D–π-A structure. Their maximum absorption wavelengths were in the range 570–586 nm and they had relatively large molar absorption coefficients, while their maximum emission wavelengths in the red light region were in the range 596–611 nm. Moreover, their fluorescence intensity in glycerol was 35–184 times higher than that in phosphate buffer solution (PBS). The lg(Fl) and lg η of probes 1a–d showed good linearity with high correlation coefficients according to the Förster–Hoffman equation. In addition, cell staining experiments demonstrated that 1a–c could target lysosomes, endoplasmic reticulum and mitochondria, respectively. They could also undergo viscosity-detectable changes in the corresponding organelles under the action of the corresponding ion carriers. [ABSTRACT FROM AUTHOR]

The reaction of [(Me/BnTPEN)RuII(NCCH3)]2+ (BnTPEN = N1-benzyl-N1,N2,N2-tris(pyridine-2-ylmethyl)ethane-1,2-diamine and MeTPEN = N1-methyl-N1,N2,N2-tris(pyridine-2-ylmethyl)ethane-1,2-diamine) with mCPBA in the presence of chloride ions in CH3CN : H2O generated a novel (Me/BnTPEN)RuIII–OCl species at room temperature. This hypochlorite adduct could also be obtained by the direct reaction of NaOCl and HClO4 with (L)RuII complexes. The current study mimics the synthesis of a metal hypochlorite adduct in a similar fashion as in the heme-dependent haloperoxidase enzyme. As an electrophilic oxidant, the ruthenium hypochlorite adduct catalyzes hydrogen atom abstraction reactions of phenols and their derivatives. [ABSTRACT FROM AUTHOR]

In recent decades, the use of thermoset epoxy resins (ER) has spread to countless applications due to their mechanical properties, heat resistance and stability. However, these ERs are neither biodegradable nor recyclable due to their permanent crosslinked networks and usually, they are synthesized from fossil and toxic precursors. Therefore, reducing its consumption is of vital importance to the environment. On the one hand, the solution to the recyclability problems of epoxy resins can be achieved through the use of vitrimers, which have thermoset properties and can be recycled as thermoplastic materials. On the other hand, vitrimers can be made from natural sources, reducing their toxicity. In this work, a sustainable epoxy vitrimer has been efficiently synthesized, VESOV, by curing epoxidized soybean oil (ESO) with a new vanillin-derived Schiff base (VSB) dynamic hardener, aliphatic diamine (1,4-butanediamine, BDA) and using 1,2-dimethylimidazole (DMI) as an accelerator. Likewise, using the same synthesized VSB agent, a commercial epoxy resin has also been cured and characterized as ESO. Finally, different percentages (30, 50 and 70 wt%) of the same ER have been included in the formulation of VESOV, demonstrating that only including 30 wt% of ER in the formulation is able to improve the thermo-mechanical properties, maintaining the VESOV's inherent reprocessability or recyclability. In short, this is the first approach to achieve a new material that can be postulated in the future as a replacement for current commercial epoxy resins, although it still requires a minimum percentage of RE in the formulation, it makes it possible to recycle the material while maintaining good mechanical properties. [ABSTRACT FROM AUTHOR]

Systematic studies of crystalline compounds formed in aqueous systems containing aliphatic diamines, divalent transition metal halides, and selenious acid resulted in the discovery of a large family of new complex species corresponding to several new structure types. With ethylenediamine (en), layered (enH2)[M(HSeO3)2X2] compounds are the most commonly formed species which constitute a significant contribution to the family of layered hydrogen selenites containing neutral [M(HSeO3)2] (M = Mg, Mn, Co, Ni, Cu, Zn, Cd) 2D building blocks. In contrast to some previous suggestions, piperazine (pip), as well as its homologue N-methylpiperazine, mostly give rise to quite different, sometimes more complex, structures of varied dimensionality while the (pipH2)[M(HSeO3)2X2] compounds are formed only with M = Cu and Cd. In addition, metal-, halide-, or selenium-free by-product species are observed. The SeIV can be present in a multitude of forms, including H2SeO3, HSeO3−, SeO32−, and Se2O52−, reflecting amazing adaptability to the shape of the templating cations. [ABSTRACT FROM AUTHOR]

Keywords: electrosynthesis; asymmetric synthesis; chirality; anodic oxidation; cathodic reduction; electrolysis; homogeneous catalysis; radicals EN electrosynthesis asymmetric synthesis chirality anodic oxidation cathodic reduction electrolysis homogeneous catalysis radicals 2926 2942 17 08/31/23 20230915 NES 230915 Graph 1 Introduction The present-day concerns with environmental protection are driving chemists more and more to find cleaner, step-economical and low-waste generating approaches to synthesis, which also use readily available starting materials and do not consume much energy. It was postulated that the benzylic radicals, obtained by single electron oxidation, underwent radical-radical coupling with a radical formed by a chiral catalyst bound-substrate in a manner similar to that of the previous example (Scheme 1). Key to success was the ability of the rhodium catalyst to reduce the oxidation potential of the catalyst-bound substrate in its enolate form B I b , after deprotonation, allowing a mild and selective anodic oxidation reaction to take place (Scheme 2). 2.3 Alkynylation [C(sp 3)-C(sp) Bond Formation] Although the Shono oxidation for the -functionalization of amines is one of the most studied anodic oxidation reactions, catalytic asymmetric variants of the reaction have not been very much explored. [Extracted from the article]

Ascorbic acid could be applied as a recyclable organocatalyst for the preparation of pyrroles via Paal–Knorr condensation of hexane-2,5-dione with various mono- and diamines. The reaction proceeded smoothly to afford the desired products in moderate to excellent yields under solvent-free conditions. Moreover, the investigations on diamine reactants revealed that both the amount of loaded catalyst and steric or electronic property of substrates are major factors in the selective formation of the corresponding bis-pyrrole or mono-pyrrole products. Density functional theory methods have been employed to provide a better understanding of the catalytic mechanism of ascorbic acid in this reaction. The optimized calculations pointed out the presence of three possible bifunctional hydrogen bond donor sites and one hydrogen bond acceptor site in the molecular structure of ascorbic acid. Although all four possible complexes were studied, the two bidentate hydrogen bond complexes between ascorbic acid and the carbonyl group of hexane-2,5-dione (average hydrogen bond distance ~ 1.8–1.9 Å) were the most stable complexes. MEP maps and NBO analysis of the complexes are in consistent with the obtained free energy. Furthermore, the reduced HOMO–LUMO energy gap values support an increase in the chemical reactivity of catalyzed hexane-2,5-dione toward aniline. Ascorbic acid could be applied as a recyclable bifunctional hydrogen bond organocatalyst for the preparation of pyrroles via Paal–Knorr condensation of hexane-2,5-dione with various mono- and diamines. The DFT calculations support the existence of bidentate hydrogen bond interactions of ascorbic acid with substrates which facilitates the reaction. [ABSTRACT FROM AUTHOR]

Novel organometallic complexes Mn(benzene-1,2-diamine)(CO)3Br, Mn-1, Mn(3-methylbenzene-1,2-diamine)(CO)3Br, Mn-2, and Re(benzene-1,2-diamine)(CO)3Cl, Re-1, have been synthesized and characterized by IR, UV/Vis, 1H-NMR, EA and HRMS. The structures of Mn-2 and Re-1 were confirmed by X-ray crystallography. The three novel compounds were studied for their electrocatalytic reduction of carbon dioxide to carbon monoxide using cyclic voltammetry in acetonitrile solutions. Controlled potential electrolysis was used to obtain information on faradaic yield, with product formation being confirmed by GC. Using earth-abundant manganese, compounds Mn-1 and Mn-2 display turnover frequencies of 108 s−1 and 82 s−1, respectively, amid selective production of carbon monoxide (faradaic yields ~85%), with minimal co-production of dihydrogen (<2%), and low overpotential of 0.18 V. The rhenium congener, Re-1, displays no activity as an electrocatalyst for carbon dioxide reduction under identical conditions. [ABSTRACT FROM AUTHOR]

A highly diastereoselective addition of nitromethane to the C=N bond of enantiomeric fluorine containing Ellman's aldimines, RFCH=NS(O)tert‐Bu (RF=CF3, CF2Br, C2F5, HC2F4), has been successfully developed. The synthetic potential of the resulting β‐nitrosulfinylamides was demonstrated through their conversion into optically active α‐fluoroalkylated 1,3‐nitroamines, 1,3‐diamines, and 4‐fluoroalkylated imidazolidin‐2‐ones. [ABSTRACT FROM AUTHOR]

A green one-pot synthesis of 3,3′-(1,4-phenylene)bis[2-(furan/thiophen/pyrrol-2-yl)-2,3-dihydro-quinazolin-4(1H)-one] derivatives in 85–90% yield have been developed by using 1H-1,3-benzoxazine-2,4-dione, furane-, thiophene-, or 1H-pyrrole-2-carbaldehyde, and benzene-1,4-diamine as starting materials in the presence of L-proline as catalyst in ethanol at 65–70°C for 90–120 min. The anticancer potential of the synthesized compounds against SKOV3 and DU145 cells has been evaluated, and 1-methyl-5-nitro-1H-pyrrol-2-yl derivative 4h exhibited the prominent activity against SKOV3 and DU145 cells with an IC50 values of 8.5 and 7.9 µM, respectively. The in silico study of the most active compound (–10.8 kcal/mol) showed good binding energies toward human mitogen-activated protein kinase. [ABSTRACT FROM AUTHOR]

Polymeric optical films with light colors, good optical transparency and high thermal resistance have gained increasing attention in advanced optoelectronic areas in recent years. However, it is somewhat inter-conflicting for achieving the good optical properties to the conventional thermal resistant polymers, such as the standard aromatic polyimide (PI) films, which are well known for the excellent combined properties and also the deep colors. In this work, a series of wholly aromatic PI films were prepared via the polycondensation chemistry of one fluorene-containing dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (FDAn) and several aromatic diamines with amide linkages in the main chain, including 9,9-bis [4-(4-aminobenzamide)phenyl]fluorene (FDAADA), 2,2′-bis(trifluoromethyl)-4,4′-bis[4-(4-aminobenzamide)] biphenyl (ABTFMB), and 2,2′-bis(trifluoromethyl)-4,4′-bis[4-(4-amino-3-methyl)benzamide] biphenyl (MABTFMB). The derived FLPI-1 (FDAn-FDAADA), FLPI-2 (FDAn-ABTFMB) and FLPI-3 (FDAn-MABTFMB) resins showed good solubility in the polar aprotic solvents, such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and dimethyl sulfoxide (DMSO). The solution-processing FDAn-PI films exhibited good optical transmittance over 80.0% at a wavelength of 500 nm (T500), yellow indices (b*) in the range of 1.01–5.20, and haze values lower than 1.0%. In addition, the FDAn-PI films showed low optical retardance with optical retardation (Rth) values in the range of 31.7–390.6 nm. At the same time, the FDAn-PI films exhibited extremely high glass transition temperatures (Tg) over 420 °C according to dynamic mechanical analysis (DMA) tests. The FDAn-PI films showed good dimensional stability at elevated temperatures with linear coefficients of thermal expansion (CTE) in the range of (31.8–45.8) × 10−6/K. [ABSTRACT FROM AUTHOR]

Industrial polyureas are typically synthesized using diisocyanates via two possible alternative pathways: the extremely quick and highly exothermal diamine–diisocyanate pathway and the relatively slow and mild water–diisocyanate pathway. Although polyurea synthesis via the water–diisocyanate pathway is known and has been industrially applied for many decades, there is surprisingly very little analytical information in the literature in relation to the type and extent of the occurring side reactions and the resulting chemical structures following this synthesis pathway. The synthesis of polyureas exhibiting very high concentrations of carbonyl-containing groups resulted in strong and accurate diagnostic analytical signals of combined FTIR and solid-state 13C NMR analysis. Despite the strictly linear theoretical chemical structure designed, the syntheses resulted in highly nonlinear and crosslinked polymers. It was analytically found that the water–diisocyanate pathway preferentially produced highly dominant and almost equal contents of both biuret structures and tertiary oligo-uret structures, with a very small occurrence of urea groups. This is in strong contrast with the chemical structures previously obtained via the diamine–diisocyanate polyurea synthesis pathway, which almost exclusively resulted in biuret structures. The much slower reaction and crosslinking rate of the water–diisocyanate synthesis pathway enabled the further access of isocyanate groups to the already-formed secondary nitrogens, thus facilitating the formation of complex hierarchical tertiary oligo-uret structures. [ABSTRACT FROM AUTHOR]

Skin photoaging due to ultraviolet B (UVB) exposure generates reactive oxygen species (ROS) that increase matrix metalloproteinase (MMP). Chlorin e6-photodynamic therapy (Ce6-PDT), in addition to being the first-line treatment for malignancies, has been shown to lessen skin photoaging, while curcumin is well known for reducing the deleterious effects of ROS. In the current study, PDT with three novel Ce6-curcumin derivatives, a combination of Ce6 and curcumin with various linkers, including propane-1,3-diamine for Ce6-propane-curcumin; hexane-1,6-diamine for Ce6-hexane-curcumin; and 3,3′-((oxybis(ethane-2,1-diyl))bis(oxy))bis(propan-1-amine) for Ce6-dipolyethylene glycol (diPEG)-curcumin, were studied for regulation of UVB-induced photoaging on human skin fibroblast (Hs68) and mouse embryonic fibroblast (BALB/c 3T3) cells. We assessed the antiphotoaging effects of Ce6-curcumin derivatives on cell viability, antioxidant activity, the mechanism of matrix metalloproteinase-1 and 2 (MMP-2) expression, and collagen synthesis in UVB-irradiated in vitro models. All three Ce6-curcumin derivatives were found to be non-phototoxic in the neutral red uptake phototoxicity test. We found that Ce6-hexane-curcumin-PDT and Ce6-propane-curcumin-associated PDT exhibited less cytotoxicity in Hs68 and BALB/c 3T3 fibroblast cell lines compared to Ce6-diPEG-curcumin-PDT. Ce6-diPEG-curcumin and Ce6-propane-curcumin-associated PDT showed superior antioxidant activity in Hs68 cell lines. Further, in UVB-irradiated in vitro models, the Ce6-diPEG-curcumin-PDT greatly attenuated the expression levels of MMP-1 and MMP-2 by blocking mitogen-activated protein kinases (MAPKs), activator protein 1 (AP-1), and tumor necrosis factor-α (NF-κB) signaling. Moreover, Ce6-diPEG-curcumin effectively inhibited inflammatory molecules, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, while accelerating collagen synthesis. These results demonstrate that Ce6-diPEG-curcumin may be a potential therapy for treating skin photoaging. [ABSTRACT FROM AUTHOR]

The reactions of 4-aryl-1-tosyl-1,2,3-triazoles with substituted primary 2- or 4-nitroanilines, catalyzed by dirhodium tetrapivalate were used to synthesize stable (Z)-N-aryl-N'-tosylethene-1,2-diamines. The analogous reaction of 4-phthalimido-1-tosyl-1H-1,2,3-triazole with 2-bromo-4-nitroaniline proceeded upon heating in the absence of catalyst, providing the first example for non-catalytic insertion of a carbene generated from 1-sulfonyl-1,2,3-triazole into an N–H bond. All ethene-1,2-diamines were isolated without resorting to chromatographic purification. The synthesized ethene-1,2-diamines contained two NH groups in a cis relationship and present interest as new bidentate ligands, as well as substrates for the synthesis of N,N-heterocycles. [ABSTRACT FROM AUTHOR]

This review presents all currently known macroheterocyclic compounds that include a bispidine (3,7-diazabicyclo[3.3.1]nonane) fragment in their structure. A classification of bispidine-containing macroheterocycles, which is based on the ring size and the nature of bispidinic nitrogen atoms, is suggested. Synthetic approaches to the studied compounds are classified and considered. The features of the crystal structures and solution behavior of bispidine macroheterocycles are analyzed. Prospects for the development of these organic receptors are proposed. [ABSTRACT FROM AUTHOR]

A monosubstituted benzene-1,2-diamine building block, N1-(3,5-bis(trifluoromethyl)benzyl)benzene-1,2-diamine, was prepared in two steps from commercially available 3,5-bis(trifluoromethyl)benzylamine and 1-fluoro-2-nitrobenzene, while the use of 3,5-bis(trifluoromethyl)aniline as the starting amine gave a triarylamine, N,N-bis(2-nitrophenyl)-3,5-bis(trifluoromethyl)aniline. The structures of the newly synthesized compounds were fully characterized. [ABSTRACT FROM AUTHOR]

A crystal structure and thermal characterization of a multisite Schiff base containing N2O2-inner and O4-outer coordination sites are reported. The title compound was characterized by X-ray structure analysis, 1H-NMR, 13C-NMR and ATR-FTIR spectroscopy, TG/DSC and TG-FTIR techniques. The compound crystallizes as a methanol solvate in the triclinic system, space group P 1 ¯ . The stable at room temperature compound, during heating in the air, first loses a methanol molecule. At higher temperature, the sample decomposition is associated with a strong exothermic effect and the emission of large amounts of carbon dioxide, carbon monoxide and ammonia. [ABSTRACT FROM AUTHOR]

1,2,5-Oxadiazol-3-amines with a heterocyclic substituent in the 4-position are being intensively investigated as compounds with valuable pharmacological activity. In this communication, the reaction of 1,2,5-oxadiazole-3,4-diamine with 2,5-hexanedione was shown to selectively give 4-(2,5-dimethyl-1H-pyrrol-1-yl)-1,2,5-oxadiazol-3-amine as a product of the Paal–Knorr reaction. The structure of the synthesized compound was established by elemental analysis, high-resolution mass spectrometry, 1H and 13C NMR, and IR spectroscopy. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) continue to be one of the biggest problems for air quality and it is becoming increasingly urgent to find new systems capable of limiting their concentration in the atmosphere. Thanks to their capacity to recognize halogenated derivatives, Pillar[5]arenes were used to form high performance thermosets able to absorb chlorine and bromide-based VOCs. Initially, poly(2-vinyl-4,4-dimethylazlactone) featuring different chain length were synthetized and modified by ring opening reaction by mono-amino substituted P[5]A. The high-Tg polymers obtained were then crooslinked by isophore diamine to form high performance materials featuring Tg up to 150 °C and storac modulus G′ up to 85 MPa. The ability of P[5]A cavities to capt VOCs was investigated by vapor sorption tests in presence of dichloromethane, 1,2-dibromoethane, dibromochloromethane and 1,1,2,2-tetrachloroethane. The P[5]A-based thermosets shown to be efficient to absord these carcenogenic VOCs and, this efficiency depends on the affinity of cavities for the studied VOCs, proving that these new generation of thermosets seems to be selective towards certain VOCs. [ABSTRACT FROM AUTHOR]

The complex [PtCl2(cyclohexane-1R,2R-diamine)] has been combined in a Pt(IV) molecule with two different bioactive molecules (i.e., the histone deacetylase inhibitor 2-propylpentanoic acid or valproic acid, VPA, and the potential antimetastatic molecule 4-isopropenylcyclohexene-1-carboxylic acid or perillic acid, PA) in order to obtain a set of multiaction or multitarget antiproliferative agents. In addition to traditional thermal synthetic procedures, microwave-assisted heating was used to speed up their preparation. All Pt(IV) complexes showed antiproliferative activity on four human colon cancer cell lines (namely HCT116, HCT8, RKO and HT29) in the nanomolar range, considerably better than those of [PtCl2(cyclohexane-1R,2R-diamine)], VPA, PA, and the reference drug oxaliplatin. The synthesized complexes showed pro-apoptotic and pro-necrotic effects and the ability to induce cell cycle alterations. Moreover, the downregulation of histone deacetylase activity, leading to an increase in histone H3 and H4 levels, and the antimigratory activity, indicated by the reduction of the levels of matrix metalloproteinases MMP2 and MMP9, demonstrated the multiaction nature of the complexes, which showed biological properties similar to or better than those of VPA and PA, but at lower concentrations, probably due to the lipophilicity of the combo molecule that increases the intracellular concentration of the single components (i.e., [PtCl2(cyclohexane-1R,2R-diamine)], VPA and PA). [ABSTRACT FROM AUTHOR]

The design of heat-resistant energetic compounds generally employs symmetry, planarity, and multi-hydrogen bonds to obtain compounds with high density, good thermal stability, and low sensitivity. In this paper, a heat-resistant hydrazine-bridged compound, 6,6′-(hydrazine-1,2-diyl)bis(5-nitropyrimidine-2,4-diamine) (PHP), was designed and synthesized with the strategy of multi-fused conjugated structure constructed by hydrogen bonds. The compound featured high symmetry, high planarity, and strong conjugation with good thermal stability (364 °C). This strategy provides a basis for the design of heat-resistant energetic compounds. [ABSTRACT FROM AUTHOR]

The hazardous, toxic, and flammable solvents, methyl and ethyl cellosolves (2‐methoxy‐ and 2‐ethoxyethanols), are typically used as media for the synthesis of guanamines (1,3,5‐triazine‐2,4‐diamines). We found that these problematic solvents can be efficiently replaced by a green alternative, polyethylene glycol 400 (PEG 400). The reaction efficiency in PEG 400 media was further improved by applying focused microwave irradiation. The method scope is illustrated by the preparation of twenty diverse 1,3,5‐triazine‐2,4‐diamines. [ABSTRACT FROM AUTHOR]

Catalyzed by BiCl3, aromatic o-diamines reacted with ketones efficiently to produce 1,5-benzodiazepines in good to excellent yields by condensation–cyclization reaction. Using aldehydes as substrates, mono- or disubstituted benzimidazoles were obtained as the final products. All reactions were carried out under mild reaction conditions and showed good functional group compatibility. [ABSTRACT FROM AUTHOR]

The review presents approaches to the synthesis of trifluoromethyl-containing N,O,S-heterocyclic compounds such as imidazolidin-2-ones(thiones), 1,2,4-triazine-3-thiones(ones), 1,2,4-triazine-3-amines, bis(trifluoromethyl)-2,3-dihydropyrazine-1,4-dioxides based on reactions of perfluorobiacetyl with bi- and trifunctional nucleophilic agents: urea, N- and N,N′-substituted ureas, thiourea, thiosemicarbazide, semicarbazide hydrochloride, aminoguanidine bicarbonate, and N,N′-dihydroxy-2,3-dimethylbutane-2,3-diamine. The reaction of 4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazilidin-2-one with urea in N,N-dimethylacetamide at elevated temperature afforded bis(trifluoromethyl)-glycoluril. Monosubstituted N-alkyl(aryl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-ones reacted with urea under similar conditions to give 1-alkyl(aryl)bis(trifluoromethyl)imidazooxazoles. The condensation reaction of trifluoromethyl-containing imidazolidin-2-ones(thiones) with thiourea and NH4SCN in a dipolar aprotic solvent at elevated temperature resulted in thioglycolurils, thioxoimidazothiazolones, and oxoimidazothiazolones. The first nitrogen-containing heterocycles containing a CF3 group at the vicinal position to the N-O fragment were synthesized by the reaction of perfluorobiacetyl with N,N′-dihydroxy-2,3-dimethylbutane-2,3-diamine. [ABSTRACT FROM AUTHOR]

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A three‐component synthesis methodology is described for the formation of covalent organic frameworks (COFs) containing extended aromatics. Notably, this approach enables synthesis of the building blocks and COF along parallel reaction landscapes, on a similar timeframe. The use of fragmental building block components, namely pyrene dione diboronic acid as aggregation‐inducing COF precursor and the diamines o‐phenylenediamine (Ph), 2,3‐diaminonaphthalene (Naph), or (1R,2R)‐(+)‐1,2‐diphenylethylenediamine (2Ph) as extending functionalization units in conjunction with 2,3,6,7,10,11‐hexahydroxytriphenylene, resulted in the formation of the corresponding pyrene‐fused azaacene, i.e. Aza‐COF series with full conversion of the dione moiety, long‐range order, and high surface area. In addition, the novel three‐component synthesis was successfully applied to produce highly crystalline, oriented thin films of the Aza‐COFs with nanostructured surfaces on various substrates. The Aza‐COFs exhibit light absorption maxima in the blue spectral region, and each Aza‐COF presents a distinct photoluminescence profile. Transient absorption measurements of Aza‐Ph‐ and Aza‐Naph‐COFs suggest ultrafast relaxation dynamics of excited‐states within these COFs. [ABSTRACT FROM AUTHOR]

A hybrid methodology is used to combine the favorable properties of non‐isocyanate polyurethanes (NIPUs) in the side chains with poly(methacrylates) as the backbone into thermoset hybrid resins with hydroxyurethane linkages (HNIPU)s. Using NIPUs linkages avoids the use of toxic isocyanates in the poly(urethane) segments. The backbone is synthesized from cyclic carbonated copolymer templates derived from atom transfer radical polymerization (ATRP) of an alkyl methacrylate (C13MA with average side‐chain length of 13)/glycidyl methacrylate (GMA) mixtures (initial GMA mol fraction = 0.1–0.4). The resulting flexible resins with pendent epoxy functional groups were subsequently carbonated and then reacted with 1,10‐diaminodecane (90°C, 24 h) to form rigid side chains via hydroxyurethane linkages. Manipulating template functionality (2–11 urethane linkages out of 35 backbone units) yielded crosslinked networks with Young's moduli from 0.1 to 71.9 MPa while decreasing tensile elongation at break from 105% to 10%. Swelling ratios (SR) of the networks in tetrahydrofuran (THF) decrease as urethane linkage concentration increases, indicating tighter networks, consistent with the rheologically obtained molecular weight between crosslinks. Gel content indicated less than 15% of the networks are soluble in THF. The HNIPU networks derived show their ready tunability by simply changing the precursor functionality. [ABSTRACT FROM AUTHOR]

Benzimidazoles are a versatile class of scaffolds with important biological activities, whereas their synthesis in a lower‐cost and more efficient manner remains a challenge. Here, we demonstrate a conceptually new radical route for the high‐performance photoredox coupling of alcohols and diamines to synthesize benzimidazoles along with stoichiometric hydrogen (H2) over Pd‐decorated ultrathin ZnO nanosheets (Pd/ZnO NSs). The mechanistic study reveals the unique advantage of ZnO NSs over other supports and particularly that the features of Pd nanoparticles in facilitating the cleavage of the α‐C−H bond of alcohols and adsorbing subsequently‐generated C‐centered radicals hold the key to turning on the reaction. This work highlights a new insight into radical‐induced efficient benzimidazole synthesis pairing with H2 evolution by rationally designing semiconductor‐based photoredox systems. [ABSTRACT FROM AUTHOR]

A synthetic method to prepare 1,2‐diamines efficiently that relies on the 4CzPN‐catalysed α‐aminoalkylation of azomethine imines by secondary and tertiary α‐silylamines under blue light emitting diode (LED) light (456 nm) is described. Achieved under metal‐ and additive‐free reaction conditions at room temperature, the synthetic protocol was shown to afford product yields up to 99% and applicable to the late‐stage functionalisation of three drug molecules and the gramme‐scale preparation of one example. [ABSTRACT FROM AUTHOR]

Light-colored and transparent polyimide (PI) films with good high-temperature dimensional stability are highly desired for advanced optoelectronic applications. However, in practice, the simultaneous achievement of good optical and thermal properties in one PI film is usually difficult due to the inter-conflicting molecular design of the polymers. In the present work, a series of PI-SiO2 nanocomposite films (ABTFCPI) were developed based on the PI matrix derived from hydrogenated pyromellitic anhydride (HPMDA) and an aromatic diamine containing benzanilide and trifluoromethyl substituents in the structure, 2,2′-bis(trifluoromethyl)-4,4′-bis [4-(4-aminobenzamide)]biphenyl (ABTFMB). The inorganic SiO2 fillers were incorporated into the nanocomposite films in the form of colloidal nanoparticles dispersed in the good solvent of N,N-dimethylacetamide (DMAc) for the PI matrix. The derived ABTFCPI nanocomposite films showed good film-forming ability, flexible and tough nature, good optical transparency, and good thermal properties with loading amounts of SiO2 up to 30 wt% in the system. The ABTFCPI-30 film with a SiO2 content of 30 wt% in the film showed an optical transmittance of 79.6% at the wavelength of 400 nm (T400) with a thickness of 25 μm, yellow index (b*) of 2.15, and 5% weight loss temperatures (T5%) of 491 °C, which are all comparable to those the pristine ABTFCPI-0 matrix without filler (T400 = 81.8%; b* = 1.77; T5% = 492 °C). Meanwhile, the ABTFCPI-30 film exhibited obviously enhanced high-temperature dimensional stability with linear coefficients of thermal expansion (CTE) of 25.4 × 10−6/K in the temperature range of 50 to 250 °C, which is much lower than that of the AMTFCPI-0 film (CTE = 32.7 × 10−6/K). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

By reactions of both catalyzed and non‐catalyzed pathway, we attempt to show that the synthetic route of non‐isocyanate polyurethanes (NIPU) is developed quite recently. The advancement of sustainable, bio‐renewable, impermeable and moisture‐insensitive NIPU has started to contribute its role in academia and industry. In case of NIPU formulation, polycondensation of dicarbonate with diamine precursors as well as waste‐free polyaddition of multifunctional cyclic carbonates with diamines via ring‐opening polymerization. Obviously, since the hydroxyl groups (both primary and secondary hydroxyl group) arisen in NIPU is employed to reveal fairly different attributes compared to trivial polyurethanes (PU). The advantage of NIPU comprises of the role of carbon dioxide and renewable feedstock, while various cyclic carbonates obtained to react with diamine substrates to incorporate desired physicochemical and mechanical properties. Indeed, NIPU are noted to be non‐toxic, biodegradable and exhibit remarkable properties. In this review, we account the imperative strategies employed in developing essential sustainable NIPU have been discussed in detail. [ABSTRACT FROM AUTHOR]

Porous organic polymers (POPs) with high porosity and tunable functionalities have been widely studied for use in gas separation, catalysis, energy conversion and energy storage. However, the high cost of organic monomers, and the use of toxic solvents and high temperatures during synthesis pose obstacles for large‐scale production. Herein, we report the synthesis of imine and aminal‐linked POPs using inexpensive diamine and dialdehyde monomers in green solvents. Theoretical calculations and control experiments show that using meta‐diamines is crucial for forming aminal linkages and branching porous networks from [2+2] polycondensation reactions. The method demonstrates good generality in that 6 POPs were successfully synthesized from different monomers. Additionally, we scaled up the synthesis in ethanol at room temperature, resulting in the production of POPs in sub‐kilogram quantities at a relatively low cost. Proof‐of‐concept studies demonstrate that the POPs can be used as high‐performance sorbents for CO2 separation and as porous substrates for efficient heterogeneous catalysis. This method provides an environmentally friendly and cost‐effective approach for large‐scale synthesis of various POPs. [ABSTRACT FROM AUTHOR]

69 Ting, C P. Xu, G. Zeng, X. Maimone, T J. J. Am. Chem. Soc. 2016, 138: 14868 70 Elkin, M. Szewczyk, S M. Scruse, A C. Newhouse, T R. J. Am. Chem. Soc. 2017, 139: 1790 71 Zhang, Y. Ji, Y. Franzoni, I. Guo, C. Jia, H. Hong, B. Li, H. Angew. Chem. 1993, 221 45 Kuehne, M R. J. Am. Chem. Soc. 1964, 86: 2946 46 Wenkert, E. Wickberg, B. J. Am. Chem. Soc. 1965, 87: 1580 47 Zhang, W. Chen, X. An, Y. Wang, J. Zhuang, C. Tang, P. Chen, F E. Chem. Eur. J. 2020, 26: 10439 48 Wee, A G. H. Yu, Q. Tetrahedron Lett. Keywords: symmetry; natural products; retrosynthesis EN symmetry natural products retrosynthesis 1949 1960 12 06/16/23 20230704 NES 230704 1 Introduction Biologically active complex molecules derived from natural sources represent a key component in current drug design and development. [75] This compound contains a novel tricyclic gamma-diketone core attached by a densely substituted cyclopentane moiety. [Extracted from the article]

Few metal complexes of Mg(II), Zn(II), Sn(II), VO(II), ions with the Schiff base ligand 2,2'-((1E,1'E)-(1,2- naphthenylenebis(azanylylidene))bis(methanylylidene))diphenol, which as prepared by the condensation of 3-hydroxythiophene-2-carbaldehyde and naphthalene-1,2- diamine, were synthesized and characterized. The solid-state isolation was used to remove the ligands and metal complexes from the reaction mixture. The UV-Visible, FT-IR and certain physio-chemical studies validated the structural and spectral features of the ligand and complexes. Studying the IR spectra of Schiff bases has shown that the N and O atoms are ligand binding sites with the metal ion. Evidence from molar conductance measurements suggests that the complexes are not electrolytic. TLC analysis was used to check the total responses. In addition to the tetrahedral geometry predicted by magnetic susceptibility data, electronic spectra for the [ZnC20H14O2N2S2], [SnC20H14O2N2S2], [VOC20H14O2N2S], [MgC20H14O2N2S] complexes indicated a square planar geometry. In order to test for antibacterial activity, the Schiff base ligands and their complexes were exposed to a disc diffusion assay. [ABSTRACT FROM AUTHOR]

Two new copper(II) complexes, [CuL] (1) and [Cu4Cl2L2(N3)2]·CH3OH (2), derived from the bis-Schiff base N,N'-bis(4-bromosalicylidene)propane-1,2-diamine (H2L) have been prepared and characterized by spectroscopy methods, as well as single crystal X-ray determination. The Cu atom in the mononuclear complex 1 is in square planar coordination. The outer and inner Cu atoms in the phenolate and azide co-bridged tetranuclear complex 2 are in square planar and square pyramidal coordination, respectively. The antibacterial activities of the Schiff base and the two copper complexes have been assayed on the bacteria Staphylococcus aureus and Escherichia coli, and the yeast Candida parapsilosis. [ABSTRACT FROM AUTHOR]

A series of Schiff base ligands obtained by the condensation of trans-cyclohexane-1,2-diamine and fluorinated benzaldehydes were prepared, followed by their reduction with NaBH4. The reduced ligands were employed in the synthesis of zinc complexes of the general formula [ZnCl2(L)]. The structures of both the original and the reduced Schiff bases, as well as of the zinc complexes, were characterized by single-crystal X-ray analysis, along with NMR and IR spectroscopy. The antimicrobial activities of the reduced Schiff bases and their zinc complexes were evaluated in vitro against E. coli, S. aureus, and C. albicans. The compounds containing the 4-(trifluoromethylphenyl) moiety showed marked antibacterial activity. Interestingly, the antimicrobial effect of the zinc complex with this moiety was significantly higher than that of the corresponding free reduced ligand, comparable with ciprofloxacin used as standard. Thus, a synergic effect upon the complexation with zinc can be inferred. [ABSTRACT FROM AUTHOR]

Heteroaromatic polyimides (PIs) containing benzimidazole have attracted tremendous attention due to their positive impact on the properties of PIs. Some research on PIs containing 4,4′-[5,5′-bi-1H-benzimidazole]-2,2′-diylbis-benzenamine (4-AB) has been reported. However, reports are lacking on homo-polyimides (homo-PIs) containing 3,3′-[5,5′-bi-1H-benzimidazole]-2,2′-diylbis-benzenamine (3-AB), which is one of the isomers of 4-AB. In this paper, the influence of amino groups' positions on the performance of homo-PIs was investigated. It was found that the net charge of the amine N group in 4-AB was lower than that of 3-AB, resulting in higher reactivity of 4-AB. Consequently, PIs containing 4-AB displayed better mechanical performance. Molecular simulation confirmed that 3-AB and its corresponding PI chain exhibited distorted conformation, leading to the PI films containing 3-AB having a lighter color. In addition, the 3-AB structure was calculated to have higher rotational energy compared to 4-AB, resulting in a higher glass transition temperature (Tg) in PIs prepared from 3-AB. On the other hand, PIs containing 4-AB exhibited a higher level of molecular linearity, leading to a lower coefficient of thermal expansion (CTE) compared to PIs prepared from 3-AB. Furthermore, all PIs showed higher thermal stability with a 5% weight loss temperature above 530 °C and Tg higher than 400 °C. [ABSTRACT FROM AUTHOR]

(Thio)‐urea‐containing bifunctional quaternary ammonium salts emerged as powerful non‐covalently interacting organocatalysts over the course of the last decade. The most commonly employed catalysts in this field are either based on Cinchona alkaloids, α‐amino acids, or trans‐cyclohexane‐1,2‐diamine. Our group has been heavily engaged in the design and use of such catalysts, i. e. trans‐cyclohexane‐1,2‐diamine‐based ones for around 10 years now, and it is therefore the intention of this short personal account to provide an overview of the, at least in our opinion, most significant and pioneering achievements in this field by looking on catalyst design and asymmetric method development, with a special focus on our own contributions. [ABSTRACT FROM AUTHOR]