Nucleophilic substitution of meso-nitrooctaethylporphyrins

1985 ◽  
Vol 63 (2) ◽  
pp. 406-411 ◽  
Author(s):  
Liang-Chu Gong ◽  
David Dolphin
Keyword(s):  
Nucleophilic Substitution ◽  
Nucleophilic Addition ◽  
Nucleophilic Aromatic Substitution ◽  
Redox Potentials ◽  
Aromatic Substitution ◽  
Halogen Atoms

Nitrooctaethylporphyrins readily undergo nucleophilic aromatic substitution in the presence of HCl or HBr. In the presence of methoxide, nucleophilic addition to give a porphodimethane occurs, followed by autoxidation to the methoxyporphyrin. Unlike the nitrated complexes, the chlorosubstituted porphyrins exhibit redox potentials similar to those of unsubstituted analogs. Meso-halogenated porphyrins do, however, show steric distortion due to the bulk of the halogen atoms.

How Does Nucleophilic Aromatic Substitution in Nitroarenes Really Proceed: General Mechanism

Synthesis ◽  
2017 ◽  
Vol 49 (15) ◽  
pp. 3247-3254 ◽  
Author(s):  
Mieczysław Mąkosza
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Nucleophilic Substitution ◽  
Experimental Studies ◽  
Secondary Reaction ◽  
Nucleophilic Aromatic Substitution ◽  
General Mechanism ◽  
Primary Process ◽  
Nucleophilic Substitution Of Hydrogen ◽  
Aromatic Substitution

On the basis of previously published experimental studies and ab initio calculations, a general corrected mechanism of nucleophilic aromatic substitution was formulated. It was shown that conventional nucleophilic substitution of halogens is a slow secondary reaction whereas nucleophilic substitution of hydrogen is the fast primary process. The general mechanism embraces both of these alternative and complementary reactions.

Ironcyclopentadienyl mediated 2-alkyl-2-arylphenylsulphonylacetonitrile synthesis

1995 ◽  
Vol 73 (2) ◽  
pp. 289-295 ◽  
Author(s):  
Alaa S. Abd-El-Aziz ◽  
Christine R. de Denus ◽  
Harold M. Hutton
Keyword(s):  
Nucleophilic Substitution ◽  
Room Temperature ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Efficient Route ◽  
Cyclopentadienyliron Complexes ◽  
Formation Of Complexes

A unique route to the synthesis of 2-alkyl-2-arylphenylsulphonylacetonitriles via the nucleophilic aromatic substitution (SNAr) of chloroarene cyclopentadienyliron complexes with 2-alkyl phenylsulphonylacetonitriles has been investigated. Reactions of chloroarene complexes (1a–d) with 2-alkyl phenylsulphonylacetonitrile (2a,b) in the presence of K2CO3 in DMF at room temperature led to the formation of complexes 3a–d and 4a,c,d in good yields. The use of alkylated phenylsulphonylacetonitriles as nucleophiles in the reactions with the p-dichlorobenzene complex (1e) allowed the formation of the disubstituted complexes (5,6). Photolytic demetallation provided an efficient route to the liberation of the arylated phenylsulphonylacetonitriles 7a–d, 8a,c,d, 9, and 10. Keywords: chloroarene, phenylsulphonylacetonitrile, nucleophilic substitution.

scholarly journals Utilizing the σ-complex stability for quantifying reactivity in nucleophilic substitution of aromatic fluorides

2013 ◽  
Vol 9 ◽  
pp. 791-799 ◽  
Author(s):  
Magnus Liljenberg ◽  
Tore Brinck ◽  
Tobias Rein ◽  
Mats Svensson
Keyword(s):  
Nucleophilic Substitution ◽  
Density Functional ◽  
Reaction Rates ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Functional Theory ◽  
Aromatic Substrates ◽  
Complex Approach ◽  
Mechanistic Analysis ◽  
Rate Limiting

A computational approach using density functional theory to compute the energies of the possible σ-complex reaction intermediates, the “σ-complex approach”, has been shown to be very useful in predicting regioselectivity, in electrophilic as well as nucleophilic aromatic substitution. In this article we give a short overview of the background for these investigations and the general requirements for predictive reactivity models for the pharmaceutical industry. We also present new results regarding the reaction rates and regioselectivities in nucleophilic substitution of fluorinated aromatics. They were rationalized by investigating linear correlations between experimental rate constants (k) from the literature with a theoretical quantity, which we call the sigma stability (SS). The SS is the energy change associated with formation of the intermediate σ-complex by attachment of the nucleophile to the aromatic ring. The correlations, which include both neutral (NH3) and anionic (MeO−) nucleophiles are quite satisfactory (r = 0.93 to r = 0.99), and SS is thus useful for quantifying both global (substrate) and local (positional) reactivity in SNAr reactions of fluorinated aromatic substrates. A mechanistic analysis shows that the geometric structure of the σ-complex resembles the rate-limiting transition state and that this provides a rationale for the observed correlations between the SS and the reaction rate.

Methylsulfone as a leaving group for synthesis of hyperbranched poly(arylene pyrimidine ether)s by nucleophilic aromatic substitution

RSC Advances ◽  
2015 ◽  
Vol 5 (17) ◽  
pp. 12821-12823 ◽  
Author(s):  
Yue Guan ◽  
Chunbo Wang ◽  
Daming Wang ◽  
Guodong Dang ◽  
Chunhai Chen ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Hyperbranched Poly ◽  
Leaving Group

Using a novel leaving group, methylsulfone activated by pyrimidine, 4,6-dichloro-2-(methylsulfonyl)pyrimidine was used to synthesize two new hyperbranched poly(arylene pyrimidine ether)s with diphenol via a nucleophilic substitution polymerization.

scholarly journals Synthesis and nucleophilic aromatic substitution of 3-fluoro-5-nitro-1-(pentafluorosulfanyl)benzene

2016 ◽  
Vol 12 ◽  
pp. 192-197 ◽  
Author(s):  
Javier Ajenjo ◽  
Martin Greenhall ◽  
Camillo Zarantonello ◽  
Petr Beier
Keyword(s):  
Nucleophilic Substitution ◽  
Title Compound ◽  
Fluorine Atom ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Vicarious Nucleophilic Substitution ◽  
Direct Fluorination ◽  
Nitrogen Nucleophiles

3-Fluoro-5-nitro-1-(pentafluorosulfanyl)benzene was prepared by three different ways: as a byproduct of direct fluorination of 1,2-bis(3-nitrophenyl)disulfane, by direct fluorination of 4-nitro-1-(pentafluorosulfanyl)benzene, and by fluorodenitration of 3,5-dinitro-1-(pentafluorosulfanyl)benzene. The title compound was subjected to a nucleophilic aromatic substitution of the fluorine atom with oxygen, sulfur and nitrogen nucleophiles affording novel (pentafluorosulfanyl)benzenes with 3,5-disubstitution pattern. Vicarious nucleophilic substitution of the title compound with carbon, oxygen, and nitrogen nucleophiles provided 3-fluoro-5-nitro-1-(pentafluorosulfanyl)benzenes substituted in position four.

Nucleophilic aromatic substitution with dialkoxycarbenes

1997 ◽  
Vol 75 (10) ◽  
pp. 1331-1335 ◽  
Author(s):  
Joseph P. Ross ◽  
Philippe Couture ◽  
John Warkentin
Keyword(s):  
Nucleophilic Substitution ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Aromatic Rings ◽  
Aryl Group ◽  
Aryl Fluoride ◽  
Intramolecular Substitution

Dimethoxycarbene, generated at 110 °C by thermolysis of 2,2-dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline, displaces fluoride from aromatic rings that are activated with electron-withdrawing groups. Intermolecular substitution on Sanger's reagent and on hexafluorobenzene are reported, together with intramolecular substitution by a dioxycarbene with a tethered aryl group. Keywords: aromatic substitution, aryl(dimethoxy)fluoromethanes, aryl fluoride, dialkoxycarbene, nucleophilic substitution.

Synthesis of Hydrazinylpyridines via Nucleophilic Aromatic Substitution and Further Transformation to Bicyclo[2.2.2]octenes Fused with Two N-Aminosuccinimide Moieties

Synthesis ◽  
2020 ◽  
Author(s):  
Krištof Kranjc ◽  
Jernej Ekar
Keyword(s):  
Nucleophilic Substitution ◽  
Hydrazine Hydrate ◽  
Diethyl Ether ◽  
Water Solubility ◽  
Halogen Bond ◽  
Bidentate Ligand ◽  
Nucleophilic Aromatic Substitution ◽  
Thick Wall ◽  
Aromatic Substitution ◽  
User Friendly

AbstractEfficient and reliable synthesis of substituted hydrazinylpyridines in thick-wall ACE tubes via nucleophilic substitution of a chlorine substituent in different chloropyridines is presented. Hydrazine hydrate and alkylhydrazines were used as nucleophiles and simple alcohols and diethyl ether were the only organic solvents necessary, making the process environmentally and user friendly, potentially reaching 100% atomic efficiency. In the next step, transformations of succinic anhydride moieties fused to the bicyclo[2.2.2]octene framework into succinimide moieties via nucleophilic substitution of oxygens were conducted. As nucleophiles two of the synthesized hydrazinylpyridines (2-hydrazinyl-3-nitropyridine and 2-hydrazinyl-5-nitropyridine) and also hydrazine hydrate, phenylhydrazine, and 4-nitrophenylhydrazine were used. Reactions were again carried out in ACE tubes and only simple alcohols, diethyl ether, and acetone were needed as solvents. One of the prepared bicyclo[2.2.2]octene adducts displayed water solubility thus being a promising candidate for future studies as a novel bidentate ligand for various metal cations in aqueous solutions or acting as an unprecedented halogen bond acceptor.

Microwave-assisted N-Arylation of Indoles via C(sp2)–N(sp2) Bond Formation by Aromatic Nucleophilic Substitution Reactions

2008 ◽  
Vol 63 (3) ◽  
pp. 298-302 ◽  
Author(s):  
Hui Xu ◽  
Ling-Ling Fan
Keyword(s):  
Reaction Time ◽  
Nucleophilic Substitution ◽  
Bond Formation ◽  
Aryl Halides ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Aromatic Nucleophilic Substitution ◽  
Short Reaction Time ◽  
Microwave Assisted

Microwave-assisted nucleophilic aromatic substitution on aryl halides with different indoles is described. Moderate to good yields are obtained in short reaction time (25 - 40 min) when coupling indoles with fluoro- and chloro-substituted aryl halides under catalyst-free conditions.

Iodinated cobalt corroles

2017 ◽  
Vol 21 (12) ◽  
pp. 900-907 ◽  
Author(s):  
Kolanu Sudhakar ◽  
Atif Mahammed ◽  
Natalia Fridman ◽  
Zeev Gross
Keyword(s):  
Similar Pattern ◽  
Reduction Potential ◽  
Crystallographic Data ◽  
Nucleophilic Aromatic Substitution ◽  
Redox Potentials ◽  
Aromatic Substitution ◽  
X Ray ◽  
Redox Active ◽  
First Time ◽  
Back Donation

Cobalt(III) complexes of selectively [Formula: see text]-pyrrole-iodinated corroles were prepared and characterized for the first time. X-ray crystallographic data reveals that the corrole macrocycle remains quite planar despite of the presence of multiple iodine substituents. The redox potentials increase linearly with the number of iodine substituents, much more for reduction than for oxidation, in a similar pattern to that of previously reported gold(III), gallium(III), and aluminum(III) complexes of [Formula: see text]-pyrrole-iodinated corroles. Their effect on reduction potential is much larger than what is observed for analogous gallium(III) and aluminum(III) corroles, wherein the chelated element is not redox active. Interestingly, the effect of iodine is similar to that of the much more electronegative halides, which is attributed to a stronger [Formula: see text]-back donation by the latter. One advantage of achieving selective iodination, in terms of the number and positioning, is that is provides an entry to further functionalization of the corrole skeleton via nucleophilic aromatic substitution.

The reaction of N-t-Butyl-2,4,6-trinitrobenzamide with sodium hydroxide. A unimolecular nucleophilic aromatic substitution

1965 ◽  
Vol 18 (5) ◽  
pp. 699 ◽  
Author(s):  
PJ Hutchison ◽  
RJL Martin
Keyword(s):  
Nucleophilic Substitution ◽  
Equilibrium Constant ◽  
Kinetic Data ◽  
Zero Order ◽  
Ion Concentration ◽  
Nucleophilic Aromatic Substitution ◽  
Anionic Complex ◽  
Aromatic Substitution ◽  
Ion Concentrations ◽  
Hydroxyl Ion

N-t-Butyl-2,4,6-trinitrobenzamide undergoes a nucleophilic substitution with hydroxyl ions to form nitrite ions. The amide is stable during this reaction and will only undergo hydrolysis under the more drastic conditions of higher hydroxyl ion concentrations at higher temperatures. The observed rate of the nucleophilic substitution is inversely proportional to the hydroxyl ion concentration. In the presence of alkali, the amide is in equilibrium with a red anionic complex and the equilibrium constant has been calculated from the kinetic data. When allowance has been made for this equilibrium, it is found that the formation of nitrite ions from the amide is zero order with respect to the hydroxyl ion concentration.

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