Tag: M.W=400-450

Wessels, Alina published the artcileFormation of Breslow Intermediates from N-Heterocyclic Carbenes and Aldehydes Involves Autocatalysis by the Breslow Intermediate, and a Hemiacetal, HPLC of Formula: 258278-25-0, the publication is Angewandte Chemie, International Edition (2022), 61(23), e202117682, database is CAplus and MEDLINE.

Under aprotic conditions, the stoichiometric reaction of N-heterocyclic carbenes (NHCs) such as imidazolidin-2-ylidenes with aldehydes affords Breslow Intermediates (BIs), involving a formal 1,2-C-to-O proton shift. We herein report kinetic studies (NMR), complemented by DFT calculations, on the mechanism of this kinetically disfavored H-translocation. Variable time normalization anal. (VTNA) revealed that the kinetic orders of the reactants vary for different NHC-to-aldehyde ratios, indicating different and ratio-dependent mechanistic regimes. We propose that for high NHC-to-aldehyde ratios, the H-shift takes place in the primary, zwitterionic NHC-aldehyde adduct. With excess aldehyde, the zwitterion is in equilibrium with a hemiacetal, in which the H-shift occurs. In both regimes, the critical H-shift is auto-catalyzed by the BI. Kinetic isotope effects observed for R-CDO are in line with our proposal. Furthermore, we detected an H-bonded complex of the BI with excess NHC (NMR).

Angewandte Chemie, International Edition published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C8H11NO, HPLC of Formula: 258278-25-0.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Zhukhovitskiy, Aleksandr V. published the artcileMigratory Insertion of Carbenes into Au(III)-C Bonds, Safety of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, the publication is Journal of the American Chemical Society (2018), 140(1), 466-474, database is CAplus and MEDLINE.

Migratory insertion of carbon-based species into transition-metal-carbon bonds is a mechanistic manifold of vast significance: it underlies the Fischer-Tropsch process, Mizoroki-Heck reaction, Ziegler-Natta and analogous late-transition-metal-catalyzed olefin polymerizations, and a number of carbonylative methods for the synthesis of ketones and esters, among others. Although this type of reactivity is well-precedented for most transition metals, gold constitutes a notable exception, with virtually no well-characterized examples known to date. Yet, the complementary reactivity of gold to numerous other transition metals would offer new synthetic opportunities for migratory insertion of carbon-based species into gold-carbon bonds. Here we report the discovery of well-defined Au(III) complexes that participate in rapid migratory insertion of carbenes derived from silyl- or carbonyl-stabilized diazoalkanes into Au-C bonds at temperatures ≥ -40 °C. Through a combined theor. and exptl. approach, key kinetic, thermodn., and structural details of this reaction manifold were elucidated. This study paves the way for homogeneous gold-catalyzed processes incorporating carbene migratory insertion steps.

Journal of the American Chemical Society published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C17H14N2O2, Safety of 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Liu, Jiangjun published the artcileNickel-Catalyzed Intramolecular Desulfitative C-N Coupling: A Synthesis of Aromatic Amines, Synthetic Route of 258278-25-0, the publication is Journal of Organic Chemistry (2020), 85(8), 5702-5711, database is CAplus and MEDLINE.

A nickel-catalyzed intramol. C-N coupling reaction via SO₂ extrusion was presented. The use of a catalytic amount of BPh₃ allowed the transformation to take place under much milder conditions (60°C) than previously reported C-N coupling reactions by CO or CO₂ extrusion (160-180°C). In addition, this method displayed good functional group tolerance and versatility, as it can be applied to the synthesis of dialkyl aryl amines, alkyl diaryl amines and triaryl amines. The robustness of the desulfitative C-N coupling was demonstrated by three high-yielding gram-scale reactions.

Journal of Organic Chemistry published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C27H39ClN2, Synthetic Route of 258278-25-0.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Zhang, Gaopeng published the artcilePalladium-catalyzed allylic alkylation reaction of α-substituted benzyl nitriles with branched allyl carbonates, Application In Synthesis of 258278-25-0, the publication is Youji Huaxue (2020), 40(10), 3399-3409, database is CAplus.

Pd-catalyzed allylic alkylation reaction of α-substituted benzyl nitriles with branched allyl carbonates in the presence of bulkier N-heterocyclic carbene ligand was reported, which provided the corresponding allylated products in good yield with high regio- and diastereo-selectivity.

Youji Huaxue published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C15H24O2, Application In Synthesis of 258278-25-0.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Yun, Je-Moon published the artcilePhotosensitive polymer brushes grafted onto PTFE film surface for micropatterning of proteins, COA of Formula: C18H34N4O5S, the publication is Journal of Materials Chemistry (2010), 20(10), 2007-2012, database is CAplus.

Surface grafting of photosensitive polymer brushes on a flexible polymer surface was performed using Ar ion irradiation, which generated peroxides on the polymer surface upon exposure to air. These peroxides were utilized as initiators for graft polymerization of a photosensitive diazoketo-functionalized methacrylate monomer. Upon UV light exposure, the diazoketo group was converted into the carboxylic acid group which was used to covalently immobilize amine-functionalized biotin in a patterned fashion. Successful binding of streptavidin to the biotin-linked regions proved the potential of the platform for biomol. patterning applications on com. polymer substrates.

Journal of Materials Chemistry published new progress about 359860-27-8. 359860-27-8 belongs to imidazoles-derivatives, auxiliary class Other Aliphatic Heterocyclic,Chiral,Amine,Amide,Ether,Inhibitor, name is N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide, and the molecular formula is C6H8N2O2S, COA of Formula: C18H34N4O5S.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Cho, Woo Kyung published the artcileChemical modification of Si nanowires for bioconjugation, Safety of N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide, the publication is Bulletin of the Korean Chemical Society (2005), 27(1), 111-114, database is CAplus.

The authors report the chem. modification of SiNWs (Si nanowires) by a combination of the formation of covalently bonded, organic monolayers on the surface of SiNWs and successive surface organic reactions. Self-assembled monolayers (SAMs) of 10-undecenyltrichlorosilane were formed on the surface of SiNWs. The terminal vinyl groups on the surface of SiNWs were oxidized to carboxylic acid groups by KMnO₄, K₂CO₃, and NaIO₃. The carboxylic acid groups were then activated with N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) and pentafluorophenol (PFP). The formation of the SAMs on SiNWs and the successive reactions were confirmed by polarized IR external reflectance spectroscopy (PIERS). After the PFP activation, any mols. with amine functional groups can be anchored onto the surface of SiNWs through an amide bond. The PFP-activated SiNWs were washed carefully with EtOH several times. The sample was then immersed in a solution of biotin-amine (10 mM in EtOH) for 30 min and washed carefully with EtOH several times. Attachment of the biotin to the SiNWs was verified PIERS and fluorescence confocal microscopy. By sonication, the SiNWs were then separated from the Si wafer and dispersed in EtOH. The dispersed SiNWs were spun off by using centrifugation.

Bulletin of the Korean Chemical Society published new progress about 359860-27-8. 359860-27-8 belongs to imidazoles-derivatives, auxiliary class Other Aliphatic Heterocyclic,Chiral,Amine,Amide,Ether,Inhibitor, name is N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide, and the molecular formula is C18H34N4O5S, Safety of N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Meng, Guangrong published the artcileA simple ¹H NMR method for determining the σ-donor properties of N-heterocyclic carbenes, HPLC of Formula: 258278-25-0, the publication is Tetrahedron Letters (2019), 60(4), 378-381, database is CAplus.

The σ-donor properties of NHC ligands (NHC = N-heterocyclic carbene) are crucial in controlling their interaction with transition metals, and as a consequence, to determine the selectivity and reactivity of NHCs in transition-metal-catalysis. Herein, we report a simple NMR method for estimating the σ-donor properties of NHC ligands based on a straightforward ¹H NMR measurement of ligand precursors. We present evaluation of σ-donating properties for a range of NHC ligands varied by structure and electronics that are relevant to transition-metal-catalysis. We expect that the simple measurement of σ-donating properties of NHCs, together with the known methods for evaluating sterics and π-backbonding, will enhance the understanding of the properties of NHCs in transition-metal-catalysis.

Tetrahedron Letters published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C27H39ClN2, HPLC of Formula: 258278-25-0.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Punna, Sreenivas published the artcileA bioorthogonal immobilization method for affinity chromatography, Related Products of imidazoles-derivatives, the publication is American Biotechnology Laboratory (2007), 25(1), 20-21, database is CAplus.

Affinity chromatog. is a powerful and generally applicable process of purifying biomols. such as antibodies, carbohydrates, and enzymes by taking advantage of the affinity of these mols. toward appropriate ligands. The immobilization of ligands to an agarose support is challenging and critical to follow a method that is not detrimental to the functional groups present in the ligand, which are necessary for the binding of the mol. to be purified. For that, the ligand should contain a functional group for immobilization to the support that is not vital to its binding property. This paper reports on the use of click reaction as a highly selective and convenient immobilization method for affinity chromatog.

American Biotechnology Laboratory published new progress about 359860-27-8. 359860-27-8 belongs to imidazoles-derivatives, auxiliary class Other Aliphatic Heterocyclic,Chiral,Amine,Amide,Ether,Inhibitor, name is N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide, and the molecular formula is C18H34N4O5S, Related Products of imidazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Punna, Sreenivas published the artcile“Clickable” agarose for affinity chromatography, Recommanded Product: N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide, the publication is Bioconjugate Chemistry (2005), 16(6), 1536-1541, database is CAplus and MEDLINE.

Successful purification of biol. mols. by affinity chromatog. requires the attachment of desired ligands to biocompatible chromatog. supports. The Cu(I)-catalyzed cycloaddition of azides and alkynes, i.e., the premier example of “click chem.”, is an efficient way to make covalent connections among diverse mols. and materials. Both azide and alkyne units are highly selective in their reactivity, being inert to most chem. functionalities and stable to wide ranges of solvent, temperature, and pH. The authors show that agarose beads bearing alkyne and azide groups can be easily made and are practical precursors to functionalized agarose materials for affinity chromatog.

Bioconjugate Chemistry published new progress about 359860-27-8. 359860-27-8 belongs to imidazoles-derivatives, auxiliary class Other Aliphatic Heterocyclic,Chiral,Amine,Amide,Ether,Inhibitor, name is N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide, and the molecular formula is C18H34N4O5S, Recommanded Product: N-(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem

Jang, Won Jun published the artcileNHC-copper-thiophene-2-carboxylate complex for the hydroboration of terminal alkynes, Formula: C27H39ClN2, the publication is Organic & Biomolecular Chemistry (2019), 17(21), 5249-5252, database is CAplus and MEDLINE.

An air-stable N-heterocyclic carbene-copper thiophene-2-carboxylate (CuTC) complex has been prepared for the stereoselective hydroboration of terminal alkynes using pinacolborane (HBpin) or 1,8-naphthalenediaminatoborane (HBdan). The newly synthesized complex can be directly activated by hydroboranes without a cocatalyst such as a base, and exhibits high reactivity for the hydroboration of alkynes under mild conditions. A gram-scale hydroboration of terminal phenylacetylene demonstrated the applicability of the copper complex for the preparation of alkenyl boronates.

Organic & Biomolecular Chemistry published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C27H39ClN2, Formula: C27H39ClN2.

Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem