403 Results Found

YS-121 [2-(4-chloro-6-(2,3-dimethylphenylamino)pyrimidin-2-ylthio)octanoic acid] is the result of target-oriented structural derivatization of pirinixic acid. It is a potent dual PPARα/γ-agonist, as well as a potent dual 5-LO/mPGES-1-inhibitor. Addit...

Network polymers with β-cyclodextrin moieties were prepared by nucleophilic substitution reactions between polyamines, linear polyethyleneimine (LPEI), polyallylamine (PAA), (ε-poly-L-lysine) (EPL), and monochlorotriazinyl-β-cyclode...

A mechanistic study of the bimolecular nucleophilic substitution (S_N2) reaction for halomethane CH₃X (X = Cl, Br, or I) is approached by using symmetry principles and molecular orbital theory. The electrophilicity of the functionalized sp³–carbon is...

As a result of our study on the interaction between the octahydrotriborate anion with nucleophiles (Nu = THF, Ph₃P, Ph₂P-(CH₂)₂-PPh₂ (dppe), Ph₃As, Et₃N, PhNH₂, C₅H₅N, CH₃CN, Ph₂CHCN)) in the presence of a wide range of Lewis acids (Ti(IV), Hf(IV), Z...

N-halosuccinimides (chloro, bromo, and iodo, respectively) were introduced, tested, and applied as efficient and non-metal precatalysts for C-, N-, O-, and X-nucleophilic substitution reactions of alcohols under solvent-free reaction conditions (SFRC...

To extend the alginate applicability for the sustained release of hydrophobic medicine in drug delivery systems, the alkyl alginate ester derivative (AAD), including hexyl alginate ester derivative (HAD), octyl alginate ester derivative (OAD), decyl...

In this study, an efficient and regioselective synthetic method was developed for the preparation of 3-hydroxy-3-((2-(naphthalen-2-yloxy)-2-oxoethoxy)carbonyl)pentanedioic acid, a multifunctional ether–ester compound of potential interest for p...

Using ¹H NMR spectroscopy, we studied the relative mobility of the NO₂ group in 1-alkyl-5-nitro-1,2,4-triazoles in the reaction of nucleophilic heterocyclic substitution by aliphatic oligoethers. The main pathways of the S_N^ipso substitution process a...

Organic chemical reactions have been used to functionalize preformed conducting polymers (CPs). The extensive work performed on polyaniline (PANI), polypyrrole (PPy), and polythiophene (PT) is described together with the more limited work on other CP...

Geometrical cis- and trans- isomers of 2-chloro-, 2-bromo- and 2-fluoro-4-methyl-1,3,2-dioxaphosphorinan-2-thiones were obtained in a diastereoselective way by (a) sulfurization of corresponding cyclic P^III-halogenides, (b) reaction of cyclic phospho...

Several bis(α-aminophosphonates) have been conveniently prepared in good yields using a straightforward multicomponent Kabachnik–Fields reaction between ethane 1,2-diamine or propane 1,3-diamine, diethylphosphite and aldehydes under catal...

A new three-component condensation of β-ketonitriles, 4-fluorobenzaldehyde, and secondary cyclic amines was developed. A possible reaction mechanism has been proposed including Knoevenagel condensation followed by aromatic nucleophilic substitut...

In this study, the degradation mechanism of chloroacetanilide herbicides in the presence of four different nucleophiles, namely: Br⁻, I⁻, HS⁻, and S₂O₃⁻², was theoretically evaluated using the dispersion-corrected hybrid functional wB97XD and the DGD...

New derivatives of 3,5-disubstituted 4H-Pyran-4-one podands (9-15) were prepared by transesterification reaction of dimethyl or diethyl 2,6-dimethyl-4H-pyran-4-one-3,5-dicarboxylate with some glycol, glycol ethers or by nucleophilic substitution of s...

Benzo[1,2-d:4,5-d′]bis([1,2,3]thiadiazole) (isoBBT) is a new electron-withdrawing building block that can be used to obtain potentially interesting compounds for the synthesis of OLEDs and organic solar cells components. The electronic structur...

Building blocks have been identified that can be functionalised by sequential nucleophilic aromatic substitution. Some examples are reported that involve the formation of cyclic benzodioxin and phenoxathiine derivatives from 4,5-difluoro-1,2-dinitrob...

An efficient synthesis of hydrolytically and thermally stable 4,8-dibromobenzo[1,2-d:4,5-d’]bis([1,2,3]thiadiazole) by the bromination of its parent heterocycle is reported. The structure of 4,8-dibromobenzo[1,2-d:4,5-d’]bis([1,2,3]thiadi...

Donor-acceptor-donor (D-A-D) type molecules are of interest as components in organic light emitting diodes (OLEDs). In this communication, 4,7-bis(2,3,3a,8b-tetrahydrocyclopenta[b]indol-4(1H)-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine was obtained by two...

Halogen bonds (XBs) between metal anions and halides have seldom been reported because metal anions are reactive for XB donors. The pyramidal-shaped Mn(CO)₅⁻ anion is a candidate metallic XB acceptor with a ligand-protected metal core that main...

Bis(alkylsulfanyl) derivatives of 1,2,5-thiadiazoles fused with aromatic and heteroaromatic rings containing long alkyl chains are of interest as compounds with liquid crystalline properties. In this communication, 4,7-bis(dodecylthio)-[1,2,5]thiadia...

Using Ni(II) as the catalyst, electron-deficient 3,5-dimethylacryloylpyrazole olefin was reacted with C,N-diarylnitrones alone for 10 min to prepare novel five-member heterocyclic products, 4-3,5-dimethylacryloylpyrazole isoxazolidines with 100% regi...

The chloride-chloride exchange reaction in arenesulfonyl chlorides was investigated experimentally and theoretically by density functional theory (DFT) calculations. The second order rate constants and activation parameters of this identity reaction...

Nanoscale control of chemical reactivity, manipulation of reaction pathways, and ultimately driving the outcome of chemical reactions are quickly becoming reality. A variety of tools are concurring to establish such capability. The confinement of gue...

Despite the poor reputation of electron-deficient pyridazines in intermolecular Hetero Diels-Alder (HDA) reactions, 4,5-dicyanopyridazine (DCP) showed a surprising reactivity as a heterocyclic azadiene in inverse electron-demand HDA processes with di...

Zeolites, both natural and synthetic, are certainly some of the most versatile minerals for their applications. Since the 1940s, they have been used in the chemical industry as catalysts, adsorbents and ion exchanger extensively, and the development...

Aminoanthraquinones were successfully synthesized via two reaction steps. 1,4-Dihydroxyanthraquinone (1) was first subjected to methylation, reduction and acylation to give an excellent yield of anthracene-1,4-dione (3), 1,4-dimethoxyanthracene-9,10...

Mechanisms are part of the high school curriculum in many countries. Although research shows that university students struggle with mechanistic reasoning, very little is known about learning mechanisms in high school. Understanding the cognitive reso...

Organothiocyanates and selenocyanates are valuable compounds, both in terms of functional group interconversion and due to their biological activities. In this contribution, we report the synthesis of a series of these important substances in a mixtu...

We characterized the stationary points along the nucleophilic substitution (S_N2), oxidative insertion (OI), halogen abstraction (XA), and proton transfer (PT) product channels of M⁻ + CH₃X (M = Cu, Ag, Au; X = F, Cl, Br, I) reactions using the...

Factors affecting the kinetic isotope effects (KIEs) of the gas-phase S_N2 reactions and their temperature dependence have been analyzed using the ion-molecule collision theory and the transition state theory (TST). The quantum-mechanical tunneling ef...

The mechanisms of three selected identity substitution reactions at phosphorus and sulfur occurring with stereospecific inversion have been investigated using density functional theory (DFT). The first identity reaction between methoxyl anion and met...

The reversible reaction of carbon dioxide (CO₂) with primary amines to form alkyl-ammonium carbamates is demonstrated in this work to reduce amine reactivity against nucleophilic substitution reactions with benzophenone and phenyl isocyanate. The rev...

We report here a benchmark study on the bimolecular nucleophilic substitution (S_N2) reaction between hydride and methane, for which we have obtained reference energies at the coupled cluster toward full configuration-interaction limit (CC-cf/CBS). Se...

The synthesis of 4-chloro-8-methylquinolin-2(1H)-one and its thione analogue is described. Some nucleophilic substitution reactions of the 4-chloro group were carried out to get new 4-substituted 2-quinolinones and quinolinethiones, such as 4-sulfany...

Uridine phosphorylases are used for biotechnological synthesis of pyrimidine derivatives and, moreover, their substrates and inhibitors are used in medicine. Therefore, studies of the mechanisms of the chemical reaction catalyzed by the enzyme and it...

In search for the cause leading to low reaction yields, each step along the reaction energy profile computed for the assumed oxidative nucleophilic substitution of hydrogen (ONSH) reaction between 2-phenylquinoxaline and lithium phenylacetylide was m...

Due to the electronic configuration of the atom and charge of the nucleus, the chlorine in organic molecules can exert a variety of effects. It can depart as a chloride anion in the process of substitution and elimination, facilitates the abstraction...

(1) The authors would like to correct mistakes in the title paper [...]

The aim of this essay is to disclose the similarity of a great variety of reactions that proceed between nucleophiles and π-electrophiles—both aromatic and aliphatic. These reactions proceed via initial reversible addition, followed by a var...

The rapid advancement of 3D packaging technology has emerged as a key solution to overcome the scaling-down limitation of advanced memory and logic devices. Redistribution layer (RDL) fabrication, a critical process in 3D packaging, requires the use...

Enzymes play a fundamental role in many biological processes. We present a theoretical approach to investigate the catalytic power of the haloalkane dehalogenase reaction with 1,2-dichloroethane. By removing the three main active-site residues one by...

Since phenol derivatives have high potential as building blocks for the synthesis of bioactive natural products and conducting polymers, many synthesis methods have been invented. In recent years, innovative synthetic methods have been developed for...

A new compound tetramethyl 1,1′-(2-[{4,5-bis(methoxycarbonyl)-1H-1,2,3-triazol-1-yl}methyl]-2-[(4-methylphenyl)sulfonamido]propane-1,3-diyl)bis(1H-1,2,3-triazole-4,5-dicarboxylate) (3) was prepared in two steps starting from 2-((4-methylphenyl)...

In this report a short and efficient synthesis of the dibenz[b,f]oxepin framework through intramolecular S_NAr and McMurry reactions is described. The diaryl ethers required for the McMurry reaction have been obtained in good yields under microwave-as...

The Lewis acid (LA)-promoted formal [3 + 2] cycloaddition (32CA) reaction of 2-phenyl-1-tosylaziridine (2PTA) with ketone has been studied within the framework of Molecular Electron Density Theory (MEDT) at the ωB97X-D/6-311G(d,p) computational...

It has been shown for a wide range of epoxy compounds that their interaction with triphenylphosphonium triflate occurs with a high chemoselectivity and leads to the formation of (2-hydroxypropyl)triphenylphosphonium triflates 3 substituted in the 3-p...

In this study, we present a complete description of the addition of a model nucleophile to the nitroaromatic ring in positions occupied either by hydrogen (the first step of the S_NAr-H reaction) or a leaving group (S_NAr-X reaction) using theoretical...

The word opium derives from the ancient Greek word ὄπιον (ópion) for the juice of any plant, but today means the air-dried seed capsule latex of Papaver somniferum. Alkaloid chemistry began with the isolation of morphi...

A highly selective one-pot microwave-assisted synthesis of 9-methoxynaphtho[1,2-b]benzofuran was obtained by treating 1-naphthol with 1-bromo-4-methoxy-2-nitrobenzene and two molar equivalents of potassium tert-butoxide in dimethyl sulfoxide. The sel...

There are great challenges in the field of natural product isolation and purification and in the pharmacological study of oligosaccharide monomers. And these isolation and purification processes are still universal problems in the study of natural pr...