scholarly journals The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

2015 ◽  
Vol 11 ◽  
pp. 385-391 ◽  
Author(s):  
Marina V Goryaeva ◽  
Yanina V Burgart ◽  
Marina A Ezhikova ◽  
Mikhail I Kodess ◽  
Viktor I Saloutin
Keyword(s):  
Nucleophilic Substitution ◽  
Alternative Pathway ◽  
Synthetic Approach ◽  
Reaction Routes

The interaction of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole is an efficient synthetic approach to novel azaheterocycles. 2-Ethoxymethylidene-3-oxo esters bearing alkyl substituents react with 5-aminotetrazole to form ethyl 2-azido-4-alkylpyrimidine-5-carboxylates which are capable of subsequent nucleophilic substitution. The use of diethyl 2-ethoxymethylidenemalonate in this reaction resulted in ethyl 7-hydroxytetrazolo[1,5-a]pyrimidine-6-carboxylate, while ethyl 2-ethoxymethylidenecyanoacetate yielded 5-[2,6-diamino-3,5-bis(ethoxycarbonyl)pyridinium-1-yl]tetrazol-1-ide through an alternative pathway. Ethyl 2-benzoyl-3-ethoxyprop-2-enoate reacted with 5-aminotetrazole by two reaction routes to form ethyl 2-benzoyl-3-(1H-tetrazol-5-ylamino)prop-2-enoate and ethyl 7-(1-ethoxy-1,3-dioxo-3-phenylpropan-2-yl)-5-phenyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate.

Modification of β-positions in porphyrazines by substitution reactions

2000 ◽  
Vol 04 (05) ◽  
pp. 555-563 ◽  
Author(s):  
OL'GA G. KHELEVINA ◽  
NATALIYA V. CHIZHOVAN ◽  
PAVEL A. STUZHIN
Keyword(s):  
Nucleophilic Substitution ◽  
Synthetic Approach ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
Radical Substitution

Peripheral modification of the porphyrazine macrocycle is an important synthetic approach to β-substituted porphyrazine derivatives, especially those which cannot be obtained via direct template cyclotetramerization of maleodinitriles and other similar synthons. The paper presents the last results of the systematical investigation of the reactivity of unsubstituted porphyrazine (tetraazaporphine) in the reactions of electrophilic and radical substitution in pyrrole rings (bromination, chlorination, chloromethylation, nitration and sulfonation) and nucleophilic substitution reactions of chloro-, bromo- and sulfo-substituted porphyrazines.

scholarly journals Efficient Synthesis of Pinoresinol, an Important Lignin Dimeric Model Compound

2021 ◽  
Vol 9 ◽  
Author(s):  
Fengxia Yue ◽  
Wu Lan ◽  
Liming Zhang ◽  
Fachuang Lu ◽  
Runcang Sun ◽  
...  
Keyword(s):  
Model Compound ◽  
Alternative Pathway ◽  
Total Yield ◽  
Coupling Reaction ◽  
High Yield ◽  
Synthetic Approach ◽  
Radical Coupling ◽  
Simple Alternative ◽  
Radical Coupling Reaction ◽  
Dimeric Model

Pinoresinol is a high-value monolignol-derived lignan used in plant defense and with human health-supporting effects. The synthetic yield and isolation efficiency of racemic pinoresinol from coniferyl alcohol by conventional radical coupling methods is sub-optimal. In this work, a facile and efficient synthetic approach was developed to synthesize pinoresinol with much higher yield. By using 5-bromoconiferyl alcohol, which was synthesized in high yield from 5-bromovanillin, to make 5,5′-bromopinoresinol via a peroxidase-mediated radical coupling reaction takes advantage of the smaller variety of radical coupling products from the 5-substituted monolignol, producing simpler product mixtures from which 5,5′-bromopinoresinol may be readily crystalized with good yield (total yield of 44.1% by NMR; isolated crystalline yield of 24.6%). Hydro-debromination of the crystalline 5,5′-bromopinoresinol to pinoresinol was essentially quantitative. Gram quantities of pinoresinol were conveniently synthesized by using this approach. This simple alternative pathway to make pinoresinol will impact pinoresinol-related research including structural characterization and modification of lignins, as well as clinical applications of pinoresinol and its derivatives.

scholarly journals Fluorine effect in nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-D-hexopyranose

2020 ◽  
Vol 16 ◽  
pp. 2880-2887
Author(s):  
Danny Lainé ◽  
Vincent Denavit ◽  
Olivier Lessard ◽  
Laurie Carrier ◽  
Charles-Émile Fecteau ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Fluorine Atom ◽  
Synthetic Approach ◽  
Nucleophilic Fluorination

In this work, we have developed a simple synthetic approach using Et3N·3HF as an alternative to the DAST reagent. We controlled the stereochemistry of the nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-4-O-triflate-β-ᴅ-talopyranose using Et3N·3HF or in situ generated Et3N·1HF. The influence of the fluorine atom at C2 on reactivity at C4 could contribute to a new fluorine effect in nucleophilic substitution. Finally, with the continuous objective of synthesizing novel multi-vicinal fluorosugars, we prepared one difluorinated and one trifluorinated alditol analogue.

Modular synthesis of carbazole substituted phthalimides as potential photocatalysts

Synthesis ◽  
2021 ◽  
Author(s):  
Zsombor Gonda ◽  
Tamás Földesi ◽  
Bálint Nagy ◽  
Zoltán Novák
Keyword(s):  
Metal Complexes ◽  
Nucleophilic Substitution ◽  
Noble Metal ◽  
High Variability ◽  
Synthetic Approach ◽  
Aromatic Nucleophilic Substitution ◽  
Modular Synthesis ◽  
Comparable Activity ◽  
Acid Anhydrides

Herein, we report the modular synthesis of carbazole functionalized phthalimides (PI), and demonstrated their applicability as catalyst in selected photocatalytic transformations. The developed synthetic approach provides high variability of phthalimide considering that the synthesis of the phthalimide core can be easily performed. Starting from fluorophthalic acid anhydrides, the corresponding fluorophthalimides were prepared with various amines, and the fluoro function ensured the introduction of carbazoles into the phthalimide framework through aromatic nucleophilic substitution. Besides the synthetic developments, we tested some of the carbazolyl phthalimides in four different photocatalytic transformations, and found attractive and comparable activity to the known 4-CzIPN and noble metal complexes.

scholarly journals (E)-3-(Aryl(arylamino)Methylene)Indolin-2-One Derivatives: An Efficient Synthetic Approach and Evaluation of their Cancer Inhibitory Activity

2018 ◽  
Vol 42 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Hongwu Jiang ◽  
Zhiyuan Feng ◽  
Taiping Chen ◽  
Zicheng Li ◽  
Wencai Huang ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Nucleophilic Substitution ◽  
Cell Lines ◽  
Inhibitory Activity ◽  
Synthetic Approach ◽  
Substituted Anilines ◽  
Hct 116 ◽  
Aryl Methyl ◽  
Simultaneous Elimination

A series of (E)-3-(aryl(arylamino)methylene)indolin-2-one derivatives were synthesised using an efficient synthetic approach. The method involved reaction of 3-bromo-3-(bromo(aryl)methyl)indolin-2-one with substituted anilines through nucleophilic substitution and a simultaneous elimination using NaHCO3 in DMF. The anticancer activity of the products against four cell lines, HCT-116, A549, SKOV3 and MDA-MB-231, was also evaluated, and several compounds showed moderate inhibitory activity.

scholarly journals Transition metal-free oxidative and deoxygenative C–H/C–Li cross-couplings of 2H-imidazole 1-oxides with carboranyl lithium as an efficient synthetic approach to azaheterocyclic carboranes

2018 ◽  
Vol 14 ◽  
pp. 2618-2626 ◽  
Author(s):  
Lidia A Smyshliaeva ◽  
Mikhail V Varaksin ◽  
Pavel A Slepukhin ◽  
Oleg N Chupakhin ◽  
Valery N Charushin
Keyword(s):  
Transition Metal ◽  
Nucleophilic Substitution ◽  
Advanced Materials ◽  
Synthetic Approach ◽  
Nucleophilic Substitution Of Hydrogen ◽  
One Pot ◽  
Metal Free

The direct C–H functionalization methodology has first been applied to perform transition metal-free C–H/C–Li cross-couplings of 2H-imidazole 1-oxides with carboranyllithium. This atom- and step-economical approach, based on one-pot reactions of nucleophilic substitution of hydrogen (SN H) in non-aromatic azaheterocycles, affords novel imidazolyl-modified carboranes of two types (N-oxides and their deoxygenative analogues), which are particularly of interest in the design of advanced materials.

Proteolytic processing of the amyloid-beta protein precursor of Alzheimer's disease

2002 ◽  
Vol 38 ◽  
pp. 37-49 ◽  
Author(s):  
Janelle Nunan ◽  
David H Small
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Alternative Pathway ◽  
Protein A ◽  
Proteolytic Processing ◽  
Gamma Secretase ◽  
Amyloid Beta Protein ◽  
Protein Precursor ◽  
Amyloid Beta Protein Precursor

The proteolytic processing of the amyloid-beta protein precursor plays a key role in the development of Alzheimer's disease. Cleavage of the amyloid-beta protein precursor may occur via two pathways, both of which involve the action of proteases called secretases. One pathway, involving beta- and gamma-secretase, liberates amyloid-beta protein, a protein associated with the neurodegeneration seen in Alzheimer's disease. The alternative pathway, involving alpha-secretase, precludes amyloid-beta protein formation. In this review, we describe the progress that has been made in identifying the secretases and their potential as therapeutic targets in the treatment or prevention of Alzheimer's disease.

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