Efficient Nucleophilic Substitution Reaction Research Articles

Near-infrared mitochondria-targeted fluorescent probe with a large Stokes shift for rapid and sensitive detection of cysteine/homocysteine and its bioimaging application

In this work, tetrahydro-acridine salt hybrid coumarin dyes was designed and developed as a Near-infrared (NIR) fluorescent probe CM for the detection and fluorescent bioimaging of Cys/Hcy. The activated chlorine atom in probe facilitates more efficient nucleophilic substitution reaction, resulting in fast responsive time (3 min toward 3 eq. Cys) and high sensitivity toward Cys with detection limit of 46 nM. More importantly, probe displays “Turn-on” near-infrared fluorescence emission (Emmax: 674 nm) with Large Strokes shift (about 200 nm) toward Cys/Hcy. Furthermore, probe could be used as efficient tool for imaging and detection of Cys/Hcy in mitochondria of living cells and in vivo. This work innovatively proposed a new design strategy for NIR fluorescent probe platform for the detection and fluorescence imaging of bio-thiols.

Efficient Monofluoroalkylation of Thiophenols or Phenols with α-Bromo-α-Fluoroketones under Mild Conditions

AbstractAn efficient nucleophilic substitution reaction between α-bromo-α-fluoroketones and thiophenols or phenols is reported for the synthesis of α-fluoro-β-ketosulfides or α-fluoro-β-ketone ethers in yields ranging from 78–93%. This method exhibits good functional group tolerance and a broad scope of nucleophilic substrates, including natural phenolic compounds.

High thermomechanical stability and ion-conductivity of anion exchange membranes based on quaternized modified poly(oxyndoleterphenylene)

Novel anion exchange membranes (AEMs) were synthesized by superacid-catalyzed step-growth polycondensation of isatine and p-terphenyl at room temperature. The materials obtained were functionalized by a highly efficient nucleophilic substitution reaction to introduce different cationic side chain lengths, this way, different degrees of functionality (DF) were achieved through modifying the molar ratios of the functionalization agent and the polymer precursor. The high solubility of the cationic polymers allowed NMR studies, additionally, the water uptake (WU), morphology, ion exchange capacity (IEC), ion-conductivity, thermal and mechanical stabilities were investigated. The membranes displayed high conductivities due to the well-defined structures and high phase segregation observed, the membrane with the longest pendant quaternary ammonium (QA) group had a conductivity of 118.7 mS cm−1 at 80 °C demonstrating its potential applicability in electrochemical devices in which ionic membranes were required. The novel AEMs were tested in a hydrogen fuel cell (HFC) and a direct methanol fuel cell (DMFC) observing high open circuit voltages (OCV) of about 1.03 V and 0.6 V for HFC and DMFC, respectively. These results are promising for fuel cells and different electrochemical devices, according to the ion conductivity observed, resistance and mechanical properties of the reported membranes.

A highly efficient nucleophilic substitution reaction between R2P(O)H and triarylmethanols to synthesize phosphorus-substituted triarylmethanes.

A highly efficient and general nucleophilic substitution reaction between dialkyl H-phosphonates or diarylphosphine oxides and triarylmethanols catalyzed by HOTf (trifluoromethanesulfonic acid) has been developed. It provides an atom-economical protocol for the synthesis of various symmetrical and unsymmetrical phosphorus-substituted triarylmethanes that constitute an emerging family of potent anticancer agents in rich diversity with 40 to 96% yields. The synthetic applicability of this protocol is demonstrated by gram-scale preparations.

Synthesis, molecular structure and spectroscopic studies of some new quinazolin-4(3H)-one derivatives; an account on the N- versus S-Alkylation

A new series of N- and S-alkylated products of 3-aryl-1H,3H-quinazolin-2,4-dione and 3-aryl-2-mercapto-3H-quinazolin-4-one, respectively, were prepared in good yields via efficient nucleophilic substitution reaction of the SH and NH substrates with methyl iodide, ethyl bromoacetate, allyl bromide, propagyl bromide, 2-bromoethanol, 1,3-dibromopropane or phenacyl bromide in DMF as a solvent and anhydrous potassium carbonate. The quinazolin-2,4-dione favored the N-alkylation while the 2-mercapto-3H-quinazolin-4-one goes via the S-alkylation. DFT reactivity studies showed that the former have the N-site with higher nucleophilicity compared to the O-site. In contrast, the S-site is the more nucleophilic centre than the N-atom of the latter. The structures of the synthesized products have been established on the basis of their melting point (m.p), IR and 1HNMR data. The molecular structures of the products were calculated using the DFT B3LYP/6-311G(d,p) method. The electronic and spectroscopic properties (Uv–Vis and NMR spectra) were calculated using the same level of theory. The chemical reactivity descriptors that could help to understand the biological activity of the products are also predicted.

Alkyl Chain Cross-Linked Sulfobutylated Lignosulfonate: A Highly Efficient Dispersant for Carbendazim Suspension Concentrate

A new family of highly water-soluble alkyl chain cross-linked sulfobutylated lignosulfonates (AASLSs) with a three-dimensional network structure and naked alkyl sulfonic acid groups were readily prepared by using 1,4-butane sultone (BS) and C6H12Br2 by a one step reaction in water, which simultaneously improved the sulfonation degree and molecular weight. GPC, 1H NMR, FTIR and functional group content tests confirmed their cross-linked chemical structure and efficient nucleophilic substitution reaction mechanism. Furthermore, the dispersion properties of AASLSs in a carbendazim suspension concentrate (SC) system were investigated. AASLS4 with high molecular weights (Mw) and moderate sulfonation degrees showed suspensibility of 99% in 45% carbendazim SC after hot storage at 50 °C for 14 days. Meanwhile, AASLS4 also showed smaller SC particle size and better rheological performance than commercial lignosulfonate. The adsorption isotherms and ζ-potential of AASLSs on carbendazim SC particles were studied to ...

Improved Synthesis of 1-(Azidomethyl)-3,5-bis-(trifluoromethyl)benzene: Development of Batch and Microflow Azide Processes

A batch process was developed to produce 1-(azidomethyl)-3,5-bis-(trifluoromethyl)benzene, 1, in 94% yield by an efficient nucleophilic substitution reaction between 3,5-bis-(trifluoromethyl)benzyl chloride, 4, and sodium azide. Hydrazoic acid (HN3), a toxic volatile compound with explosive properties, can be formed in the reactor headspace during conventional batch processing that requires significant engineering controls. In order to improve the overall safety profile, the process to produce azide 1 was optimized for operation in a microcapillary tube reactor. In addition, azide 1 was prepared in a simple biphasic solvent system using phase-transfer catalysis which results in an overall low e-factor. The product was purified via wiped film evaporation (WFE) technology.

Efficient Nucleophilic Substitution Reactions of Highly Functionalized Allyl Halides in Ionic Liquid Media.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Efficient nucleophilic substitution reactions of highly functionalized allyl halides in ionic liquid media

Nucleophilic substitution reactions of highly functionalized allyl halides with three anions, N3−, AcO−, and PhSO2−, in ionic liquid media were conducted. The ionic liquid, [Bmim][BF4], was found to be superior to classical organic solvents to give higher yields and faster reaction rates. The resulting products belong to multifunctionalized trisubstituted α,β-unsaturated ketones, which are useful building blocks for organic synthesis.

ChemInform Abstract: Efficient Nucleophilic Substitution Reactions of Pyrimidyl and Pyrazyl Halides with Nucleophiles under Focused Microwave Irradiation.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Efficient nucleophilic substitution reactions of quinolyl and isoquinolyl halides with nucleophiles under focused microwave irradiation

Nucleophilic substitution reactions of 2-chloroquinoline, 3-bromoquinoline and 4-bromoisoquinoline with thiolate, alkoxy ions and aniline were completed within several minutes under microwave irradiation. This method gives the desired products with yields up to 99% in a short reaction time, and is superior to the classical heating process.

Efficient nucleophilic substitution reactions of pyrimidyl and pyrazyl halides with nucleophiles under focused microwave irradiation

Rapid nucleophilic displacement reactions of 2-chloropyrimidine, 2-bromopyrimidine, 5-bromopyrimidine and chloropyrazine with nucleophiles under microwave irradiation was complete within several minutes with yields up to 99%. The method using microwave irradiation is superior to the classical heating processes.

ChemInform Abstract: Efficient Nucleophilic Substitution Reaction of Aryl Halides with Amino Acids under Focused Microwave Irradiation.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Efficient Nucleophilic Substitution Reaction of Aryl Halides with Amino Acids Under Focused Microwave Irradiation

The nucleophilic substitution reaction of 2,4-dinitrofluorobenzene with amino acids was complete, under microwave iradiation, within 40 s with yields up to 93%, which are far superior to those obtained under conventional heating.

Oxyethylene networks. Nucleophilic substitution reactions of chloromethylated polystyrenes in aqueous media

Some efficient nucleophilic substitution reactions have been achieved on the chloromethyl group of the polystyrene resin crosslinked with an oxyethylene chain in aqueous media.