Month: October 2022

《Modulating the Bonding Properties of N-Heterocyclic Carbenes (NHCs): A Systematic Charge-Displacement Analysis》 was published in Chemistry – A European Journal in 2017. These research results belong to Gaggioli, Carlo Alberto; Bistoni, Giovanni; Ciancaleoni, Gianluca; Tarantelli, Francesco; Belpassi, Leonardo; Belanzoni, Paola. Product Details of 852445-84-2 The article mentions the following:

In view of their intensive use as ligands in many reactions catalyzed by transition-metal complexes, modulation of the bonding properties of N-heterocyclic carbenes (NHCs) on a rational basis is highly desirable, which should enable optimization of current applications or even promote new functions. In this paper, we provide a quant. anal. of the chem. bond between a metal fragment AuCl and a series of 29 different NHCs in [(NHC)AuCl] complexes. NHCs electronic properties are modified through: (i) variation of the groups attached to the NHC nitrogen atoms or backbone; (ii) change of unsaturation/size of the NHC ring; (iii) inclusion of paracyclophane moieties; or (iv) heteroatom substitution on the NHC ring. For evaluating the donation and back-donation components of the Dewar-Chatt-Duncanson (DCD) model in the NHC-AuCl bond, we apply the charge-displacement (CD) anal. within the NOCV (natural orbitals for chem. valence) framework, a methodol. that avoids the constraint of using symmetrized structures. We show that modulation of the NHC bonding properties requires substantial modification of their structure, such as, for instance, insertion of two ketone groups into the NHC backbone (which enhances the π back-donation bond component and introduces an effective electronic communication within the NHC ring) or replacement of a nitrogen atom in the ring with an sp3 or sp2 carbon atom (which increases and decreases the π back-donation bond component, resp.). We extend our investigation by quant. comparing the NHC electronic structures for a subset of 13 NHCs in [(NHC)PPh] adducts, the 31P NMR chem. shift values of which are exptl. available. The latter have been considered as a suitable tool for measuring the NHCs π acceptor properties [Bertrand et al., Angew. Chem. Int. Ed. 2013, 52, 2939-2943]. We show that information obtained using the metal fragment can be transferred to the PPh moiety and vice versa. However, the 31P NMR chem. shift values only qual. correlate with the π acceptor properties of the NHCs, with the stronger π acidic carbenes as the most outliners. The results came from multiple reactions, including the reaction of Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2Product Details of 852445-84-2)

Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2) belongs to imidazoles.Although other azole heterocycles are ubiquitous in a wide range of biologically active natural products, imidazole rings occur predominantly in the natural amino acid histidine. Product Details of 852445-84-2 In addition, imidazole rings are part of unnatural cyclic peptides and are used as ester isosteres in peptidomimetic studies.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

HPLC of Formula: 258278-25-0On March 29, 2021, Mazars, Francois; Hrubaru, Madalina; Tumanov, Nikolay; Wouters, Johan; Delaude, Lionel published an article in European Journal of Organic Chemistry. The article was 《Synthesis of Azolium-2-dithiocarboxylate Zwitterions under Mild, Aerobic Conditions》. The article mentions the following:

Twelve imidazolium-, imidazolinium-, or benzimidazolium-2-dithiocarboxylate zwitterions with aliphatic or aromatic substituents on their nitrogen atoms, including four new unsym. 1-alkyl-3-arylimidazolium derivatives, were obtained in high yields (62-96%) upon reaction of azolium salts with CS2 and Cs2CO3 in acetonitrile at room temperature Compared to the previous strategies devised for the synthesis of NHC·CS2 betaines, this novel procedure relied on an innocuous, weak base and could be applied under mild aerobic conditions. All the new compounds were fully characterized by various anal. techniques and the mol. structures of two of them were determined by XRD anal. An associative mechanism involving the concerted reaction of the azolium salts with both CS2 and CO32- was tentatively proposed to account for the formation of the zwitterionic adducts without the intervention of free carbenes. This would explain the good results obtained with a weak inorganic base that lacks the strength needed to deprotonate the azolium salt substrates. In the experiment, the researchers used many compounds, for example, 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride(cas: 258278-25-0HPLC of Formula: 258278-25-0)

1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride(cas: 258278-25-0) may be used as a precursor to the free carbene 1,3-bis(2,6-diisopropylphenyl)-2-imidazolidinylidene, and also used as an in situ formed catalyst in a variety of reactions, e.g. amination, Heck coupling reaction, the ring-opening metathesis polymerization (ROMP), hydrogenation.HPLC of Formula: 258278-25-0In addition, it can efficiently catalyze the Suzuki-Miyaura coupling of aryl chlorides with aryl boronic acids.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Reference of Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)On March 27, 2013, Visbal, Renso; Ospino, Isaura; Lopez-de-Luzuriaga, Jose M.; Laguna, Antonio; Gimeno, M. Concepcion published an article in Journal of the American Chemical Society. The article was 《N-Heterocyclic Carbene Ligands as Modulators of Luminescence in Three-Coordinate Gold(I) Complexes with Spectacular Quantum Yields》. The article mentions the following:

The first three-coordinate gold(I) N-heterocyclic carbene (NHC) complexes have been prepared with the nido-carborane diphosphine. The complexes are brightly luminescent and present very high quantum yield values. The carbene ligand is able to modulate the energy of the emissions and, depending upon the substituent, the luminescence changes from blue to green. Theor. calculations corroborate that the emissions are phosphorescence and arise from charge transfer (LML’CT) transitions from nido-carborane ligand (L) to metal/ligand group “”gold(I)-NHC ligand”” (ML’).Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2Reference of Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)) was used in this study.

Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2) belongs to imidazoles.Imidazole rings are also present in imidazole ring alkaloids, which are potential therapeutics for thrombosis, cancer and inflammatory diseases.Reference of Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I) Although other azole heterocycles are ubiquitous in a wide range of biologically active natural products, imidazole rings occur predominantly in the natural amino acid histidine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

In 2012,European Journal of Inorganic Chemistry included an article by Landers, Brant; Navarro, Oscar. Recommanded Product: 852445-84-2. The article was titled 《Microwave-Assisted Synthesis of (N-Heterocyclic carbene)MCl Complexes of Group 11 Metals》. The information in the text is summarized as follows:

The use of microwave heating for the synthesis of (N-heterocyclic carbene)-bearing complexes of Cu, Ag and Au allows for a drastic reduction of the reaction times required by conventional heating, while affording comparable or better yields of the desired complexes. In addition to this study using Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I), there are many other studies that have used Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2Recommanded Product: 852445-84-2) was used in this study.

Chloro{1,3-bis[2,6-bis(1-methylethyl)phenyl]-4,5-dihydroimidazol-2-ylidene}gold(I)(cas: 852445-84-2) belongs to imidazoles.Although other azole heterocycles are ubiquitous in a wide range of biologically active natural products, imidazole rings occur predominantly in the natural amino acid histidine. In addition, imidazole rings are part of unnatural cyclic peptides and are used as ester isosteres in peptidomimetic studies. Recommanded Product: 852445-84-2

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Sakurai, Shun; Inagaki, Tetsuya; Kodama, Takuya; Yamanaka, Masahiro; Tobisu, Mamoru published an article on January 26 ,2022. The article was titled 《Palladium-Catalyzed Siloxycyclopropanation of Alkenes Using Acylsilanes》, and you may find the article in Journal of the American Chemical Society.Reference of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride The information in the text is summarized as follows:

Currently, catalytically transferable carbenes are limited to electron-deficient and neutral derivatives, and electron-rich carbenes bearing an alkoxy group (i.e., Fischer-type carbenes) cannot be used in catalytic cyclopropanation because of the lack of appropriate carbene precursors. We report herein that acylsilanes can serve as a source of electron-rich carbenes under palladium catalysis, enabling cyclopropanation of a range of alkenes. This reactivity profile is in sharp contrast to that of metal-free siloxycarbenes, which are unreactive toward normal alkenes. The resulting siloxycyclopropanes serve as valuable homoenolate equivalent, allowing rapid access to elaborate β-functionalized ketones. The experimental process involved the reaction of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride(cas: 258278-25-0Reference of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride)

1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride(cas: 258278-25-0) has been employed in an efficient, one-pot synthesis of N-heterocyclic carbene-allylpalladium complexes.Reference of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chlorideIn addition, it can efficiently catalyze the Suzuki-Miyaura coupling of aryl chlorides with aryl boronic acids.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

In 2013,Tugsuz, Tugba published 《A DFT study on the standard electrode potentials of 2-substituted imidazoles》.International Journal of Quantum Chemistry published the findings.SDS of cas: 16681-56-4 The information in the text is summarized as follows:

Extensive d. functional theory, calculations, with optimization of geometries and estimation of substituent effects, have been performed to investigate the electrode potentials of dimer and protonated cation structures of 2-substituted imidazoles. The gas phase geometries of dimer, anion, protonated cation, and neutral structures of 2-substituted imidazoles have been optimized using Boese-Martin for kinetics (BMK) and the Minnesota 2005 (M05) hybrid functionals combined with the valence triple-ζ quality with polarization function (TZVP) basis set. The geometries in the presence of acetonitrile solvent have been optimized using the conductor-like polarizable continuum model model of solvation at the same levels of theory. Frequency calculations have been performed for all the structures and none of them is found to exhibit any imaginary frequency. N-H—H IR harmonic frequencies have been calculated and compared with available exptl. data. The substituent effects on the electrode potentials of imidazole have been investigated as electron donating -CH3, -OH, -NH2, -OCH3 and electron withdrawing -NO2, -Cl, -F, -Br groups, which are bonded to the second numbered carbon atom of the imidazole mol. It has been found that electron donating substituents show more neg. electrode potentials, whereas electron withdrawing substituents have the opposite effect. In the part of experimental materials, we found many familiar compounds, such as 2-Bromo-1H-imidazole(cas: 16681-56-4SDS of cas: 16681-56-4)

2-Bromo-1H-imidazole(cas: 16681-56-4) is a member of imidazole. Its exclusive structural characteristics with enviable electron-rich features are favorable for imidazole-based fused heterocycles to bind efficiently with an array of enzymes and receptors in biological systems through various weak interactions like hydrogen bonds, ion-dipole, cation-π, π-π stacking, coordination, Van der Waals forces, hydrophobic effects, etc., and therefore they demonstrate widespread bioactivities. SDS of cas: 16681-56-4

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

In 2017,Niguez, Diego Ros; Guillena, Gabriela; Alonso, Diego A. published 《Chiral 2-Aminobenzimidazoles in Deep Eutectic Mixtures: Recyclable Organocatalysts for the Enantioselective Michael Addition of 1,3-Dicarbonyl Compounds to β-Nitroalkenes》.ACS Sustainable Chemistry & Engineering published the findings.Related Products of 4857-06-1 The information in the text is summarized as follows:

A catalytic system based on deep eutectic solvents (DESs) and chiral 2-amino benzimidazole organocatalysts is used to promote the enantioselective addition of 1,3-dicarbonyl compounds to β-nitrostyrenes. This procedure avoids the use of toxic volitile organic compounds (VOCs) as a reaction medium, providing access to highly functionalized chiral mols. in a selective and efficient manner. Furthermore, the reaction can be performed on a large scale and recycling the catalytic system is possible for at least four times, leading to a clean, cheap, simple, and scalable procedure that meets most of the criteria required to be a green and sustainable process. NMR studies have confirmed the key role of the hydrogen-bonding interactions between the DES and the chiral organocatalyst, which allow their recovery and the recyclability of the system. In the experiment, the researchers used 2-Chloro-1H-benzo[d]imidazole(cas: 4857-06-1Related Products of 4857-06-1)

2-Chloro-1H-benzo[d]imidazole(cas: 4857-06-1) binds to monoclonal antibodies, inhibiting their binding to their corresponding antigens. This activity may be due to its ability to bind covalently with amino groups on proteins and other molecules.Related Products of 4857-06-1

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

In 2019,Angewandte Chemie, International Edition included an article by Hedges, Jason B.; Ryan, Katherine S.. Category: imidazoles-derivatives. The article was titled 《In vitro reconstitution of the biosynthetic pathway to the nitroimidazole antibiotic azomycin》. The information in the text is summarized as follows:

Nitroimidazoles are one of the most effective ways to treat anaerobic bacterial infections. Synthetic nitroimidazoles are inspired by the structure of azomycin, isolated from Streptomyces eurocidicus in 1953. Despite its foundational role, no biosynthetic gene cluster for azomycin has been found. Guided by bioinformatics, we identified a cryptic biosynthetic gene cluster in Streptomyces cattleya and then carried out in vitro reconstitution to deduce the enzymic steps in the pathway linking L-arginine to azomycin. The gene cluster we discovered is widely distributed among soil-dwelling actinobacteria and proteobacteria, suggesting that azomycin and related nitroimidazoles may play important ecol. roles. Our work sets the stage for development of biocatalytic approaches to generate azomycin and related nitroimidazoles. In the experiment, the researchers used many compounds, for example, 1H-Imidazol-2-amine(cas: 7720-39-0Category: imidazoles-derivatives)

1H-Imidazol-2-amine(cas: 7720-39-0) belongs to anime. To avoid the problem of multiple alkylation, methods have been devised for “blocking” substitution so that only one alkyl group is introduced. The Gabriel synthesis is one such method; it utilizes phthalimide, C6H4(CO)2NH, whose one acidic hydrogen atom has been removed upon the addition of a base such as KOH to form a salt.Category: imidazoles-derivatives

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

In 2019,Journal of the American Chemical Society included an article by van Vliet, Kaj M.; Polak, Lara H.; Siegler, Maxime A.; van der Vlugt, Jarl Ivar; Guerra, Celia Fonseca; de Bruin, Bas. Recommanded Product: 530-62-1. The article was titled 《Efficient Copper-Catalyzed Multicomponent Synthesis of N-Acyl Amidines via Acyl Nitrenes》. The information in the text is summarized as follows:

Direct synthetic routes to amidines are desired, as they are widely present in many biol. active compounds and organometallic complexes. N-Acyl amidines in particular can be used as a starting material for the synthesis of heterocycles and have several other applications. Here, we describe a fast and practical copper-catalyzed three-component reaction of aryl acetylenes, amines, and easily accessible 1,4,2-dioxazol-5-ones to N-acyl amidines, generating CO2 as the only byproduct. Transformation of the dioxazolones on the Cu catalyst generates acyl nitrenes that rapidly insert into the copper acetylide Cu-C bond rather than undergoing an undesired Curtius rearrangement. For nonaromatic dioxazolones, [Cu(OAc)(Xantphos)] is a superior catalyst for this transformation, leading to full substrate conversion within 10 min. For the direct synthesis of N-benzoyl amidine derivatives from aromatic dioxazolones, [Cu(OAc)(Xantphos)] proved to be inactive, but moderate to good yields were obtained when using simple copper(I) iodide (CuI) as the catalyst. Mechanistic studies revealed the aerobic instability of one of the intermediates at low catalyst loadings, but the reaction could still be performed in air for most substrates when using catalyst loadings of 5 mol %. The herein reported procedure not only provides a new, practical, and direct route to N-acyl amidines but also represents a new type of C-N bond formation. In the experiment, the researchers used Di(1H-imidazol-1-yl)methanone(cas: 530-62-1Recommanded Product: 530-62-1)

Di(1H-imidazol-1-yl)methanone(cas: 530-62-1) is a peptide coupling reagent,it is used in the synthesis of peptides. Reacts readily with carboxylic acids to form acyl imidazoles; subsequent reaction with amines to form amides goes smoothly.Recommanded Product: 530-62-1

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem