scholarly journals Esterification vs. 1,3-Dipolar Cycloaddition Synthetic Approaches for Preparation of the Fluorescently Labelled Iron(II) Clathrochelates

2021 ◽  
Vol 14 (1) ◽  
pp. 94-100
Author(s):  
Roman A. Selin ◽  
Viktor Ya. Chernii ◽  
Dmytro V. Kryvorotenko ◽  
Andriy Mokhir ◽  
Yan Z. Voloshin
Keyword(s):  
Dipolar Cycloaddition ◽  
Synthetic Approaches

scholarly journals Nucleophilic Dearomatization of Activated Pyridines

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 632 ◽  
Author(s):  
Giulio Bertuzzi ◽  
Luca Bernardi ◽  
Mariafrancesca Fochi
Keyword(s):  
Nitrogen Heterocycles ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Organometallic Reagents ◽  
Pyridine Nitrogen ◽  
Pyridinium Ylides ◽  
Catalytic Asymmetric ◽  
Synthetic Approaches ◽  
Nitrogen Functionalization ◽  
Pyridinium Ion

Amongst nitrogen heterocycles of different ring sizes and oxidation statuses, dihydropyridines (DHP) occupy a prominent role due to their synthetic versatility and occurrence in medicinally relevant compounds. One of the most straightforward synthetic approaches to polysubstituted DHP derivatives is provided by nucleophilic dearomatization of readily assembled pyridines. In this article, we collect and summarize nucleophilic dearomatization reactions of - pyridines reported in the literature between 2010 and mid-2018, complementing and updating previous reviews published in the early 2010s dedicated to various aspects of pyridine chemistry. Since functionalization of the pyridine nitrogen, rendering a (transient) pyridinium ion, is usually required to render the pyridine nucleus sufficiently electrophilic to suffer the attack of a nucleophile, the material is organized according to the type of N-functionalization. A variety of nucleophilic species (organometallic reagents, enolates, heteroaromatics, umpoled aldehydes) can be productively engaged in pyridine dearomatization reactions, including catalytic asymmetric implementations, providing useful and efficient synthetic platforms to (enantioenriched) DHPs. Conversely, pyridine nitrogen functionalization can also lead to pyridinium ylides. These dipolar species can undergo a variety of dipolar cycloaddition reactions with electron-poor dipolarophiles, affording polycyclic frameworks and embedding a DHP moiety in their structures.

Synthetic Approaches to Nitro-Substituted Isoxazoles

Synthesis ◽  
2019 ◽  
Vol 51 (07) ◽  
pp. 1516-1528 ◽  
Author(s):  
Elena Averina ◽  
Dmitry Vasilenko ◽  
Kseniya Sedenkova ◽  
Tamara Kuznetsova
Keyword(s):  
Drug Development ◽  
Organic Synthesis ◽  
Sodium Nitrite ◽  
Preparative Method ◽  
Dipolar Cycloaddition ◽  
Dipolar Cycloadditions ◽  
Nitro Derivatives ◽  
Synthetic Approaches ◽  
Derivatives Of ◽  
Acetylene Derivatives

Nitro-substituted isoxazoles are of utmost interest both as versatile intermediates for targeted organic synthesis and as perspective bioactive compounds for drug development. Nevertheless, the existing approaches to them usually lack generality and strongly depend on the position of the nitro group and on the presence of other substituents in the isoxazole ring. This review provides the first systematization of all available data concerning synthetic approaches to 3-, 4-, and 5-nitroisoxazoles. There are a number of preparative approaches to 4-nitroisoxazoles based on classical heterocyclization reactions of nitro-substituted compounds and the nitration of isoxazoles. 3-Nitro- and, especially, 5-nitroisoxazoles are much less readily available. A few methods affording 3-nitroisoxazoles have been reported, often employing the heterocyclization of unsaturated compounds by treatment with sodium nitrite. The sole general preparative method for 5-nitroisoxazoles, containing a variety of functional groups, employs the heterocyclization of electrophilic alkenes by treatment with tetranitromethane activated with triethylamine.1 Introduction2 Synthesis of 4-Nitroisoxazoles2.1 Nitration of Isoxazoles2.2 Condensations of α-Nitro Ketones or Their Oximes2.3 1,3-Dipolar Cycloaddition of Nitrile Oxides to Acetylenes and Their Synthetic Equivalents2.4 Heterocyclization of Acetylene Derivatives by Treatment with Sodium Nitrite2.5 Heterocyclization of Nitro Derivatives of 1,3-Diketones and Their Synthetic Equivalents2.6 Miscellaneous Methods3 Synthesis of 3-Nitroisoxazoles3.1 Heterocyclization of Acetylene Derivatives or 1,3-Dihalogenoalkenes by Treatment with Sodium Nitrite3.2 Heterocyclization of Morita–Baylis–Hillman Acetates by Treatment with Sodium Nitrite3.3 1,3-Dipolar Cycloadditions4 Synthesis of 5-Nitroisoxazoles4.1 1,3-Dipolar Cycloadditions4.2 Synthesis Using Polynitro Compounds5 Conclusion

Synthetic approaches towards bisspiro[naphthalene-2(1H),3′-(3H)pyrazol]-1-one-containing compounds

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
A. Girgis ◽  
F. Osman ◽  
F. El-Samahy ◽  
I. Ahmed-Farag
Keyword(s):  
Cycloaddition Reaction ◽  
The Other ◽  
Dipolar Cycloaddition ◽  
Hydrazonoyl Chlorides ◽  
Other Hand ◽  
Synthetic Approaches

Abstract1,3-Dipolar cycloaddition reaction of bis{[4-(3,4-dihydro-(2H)-naphthalen-1-oxo-2-yl)methyl-idenephenyl]oxy}alkanes with nitrilimines (generated in situ by triethylamine dehydrohalogenation of the corresponding hydrazonoyl chlorides) in refluxing dry benzene afforded a mixture of monocycloadduct and dicycloadduct products in high regioselectivity. On the other hand, reaction of bis{[2-(3,4-dihydro-(2H)-naphthalen-1-oxo-2-yl)methylidenephenyl]oxy}alkanes with nitrilimines gave the corresponding dicycloadducts as the only isolable regioisomers.

Pyridyl disulfide-based thiol–disulfide exchange reaction: shaping the design of redox-responsive polymeric materials

2020 ◽  
Vol 11 (48) ◽  
pp. 7603-7624
Author(s):  
Ismail Altinbasak ◽  
Mehmet Arslan ◽  
Rana Sanyal ◽  
Amitav Sanyal
Keyword(s):  
Exchange Reaction ◽  
Functional Materials ◽  
Polymeric Materials ◽  
Disulfide Exchange ◽  
Redox Responsive ◽  
Synthetic Approaches

This review provides an overview of synthetic approaches utilized to incorporate the thiol-reactive pyridyl-disulfide motif into various polymeric materials, and briefly highlights its utilization to obtain functional materials.

Non-Steroidal Anti-inflammatory Drugs (NSAIDs): Synthesis of Ibuprofen, Naproxen and Nabumetone

2019 ◽  
pp. 19-27
Keyword(s):  
Review Paper ◽  
Inflammatory Drugs ◽  
Anti Inflammatory ◽  
Synthetic Approaches

This review paper covers the major synthetic approaches attempted towards the synthesis of some Non-Steroidal Anti-Inflammatory Drugs (Naproxen, Ibuprofen and Nabumetone)

Aryl-substituted Triarsiranes: Synthesis and Reactivity

2020 ◽  
Author(s):  
André Schumann ◽  
Jonas Bresien ◽  
Malte Fischer ◽  
Christian Hering-Junghans
Keyword(s):  
Organic Chemistry ◽  
Electronic Structure ◽  
Heterocyclic Carbenes ◽  
Synthetic Approaches ◽  
Inorganic And Organic

Cyclotriarsanes are rare and limited synthetic approaches have hampered reactivity studies on these systems. Described in here is a scalable synthetic protocol towards (AsAr)<sub>3</sub> (Ar = Dip, 2,6-<sup>i</sup>Pr<sub>2</sub>-C<sub>6</sub>H<sub>3</sub>; Tip, 2,4,6-<sup>i</sup>Pr<sub>3</sub>-C<sub>6</sub>H<sub>2</sub>), which allowed to study their reactivity towards [Cp<sub>2</sub>Ti(C<sub>2</sub>(SiMe<sub>3</sub>)<sub>2</sub>], affording titanocene diarsene complexes and towards N-heterocyclic carbenes (NHCs) to give straightforward access to a variety of NHC-arsinidene adducts. The electronic structure of the titanium diarsene complxes has been studied and they are best described as Ti(IV) species with a doubly reduced As<sub>2</sub>Ar<sub>2</sub> ligand. These findings will make (AsAr)<sub>3</sub> valuable precursors in the synthetic inorganic and organic chemistry.

New Pyrrolo[1,2-b]pyridazine Derivatives by 1,3-Dipolar Cycloaddition of Mesoionic Oxazolopyridazinone

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Miron Teodor Caproiu ◽  
Florea Dumitrascu ◽  
Mino R. Caira
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Pyridazine Derivatives ◽  
New Compounds

New pyrrolo[1,2-b]pyridazine derivatives 8a-f were synthesized by 1,3-dipolar cycloaddition reaction between mesoionic 1,3-oxazolo[3,2-b]pyridazinium-2-oxides and diethyl or diisopropyl acetylenedicarboxylate as alkyne dipolarophiles. The structures of the new compounds were assigned by elemental analysis and NMR spectroscopy.

Synthetic Approaches Towards the Marine Alkyl Purines

2013 ◽  
Vol 20 (22) ◽  
pp. 2798-2811 ◽  
Author(s):  
M. Gordaliza ◽  
P. Baraldi
Keyword(s):  
Synthetic Approaches
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