scholarly journals Reactions of dialkoxycarbenes with tethered triple bonds to form heterocyclic compounds

1997 ◽  
Vol 75 (2) ◽  
pp. 120-128 ◽  
Author(s):  
Karim Kassam ◽  
John Warkentin
Keyword(s):  
Intramolecular Cyclization ◽  
Triple Bond ◽  
Heterocyclic Compounds ◽  
Heterocyclic Ring ◽  
Ring Systems ◽  
Triple Bonds ◽  
Rapid Construction

Dialkoxycarbenes with a tethered triple bond, generated from the corresponding oxadiazolines, undergo an intramolecular cyclization with the tethered alkyne moiety to give 3,3-dialkoxyvinylcarbene/1,3-dipole intermediates. The regioselectivity of the carbene cyclization is highly dependent upon the nature of the alkyne substituent. In the cases where an exocyclic vinylcarbene is generated, the vinylcarbene intermediate can undergo a synthetically useful [3 + 2] cycloaddition with either an appropriate olefin or an alkyne. This approach allows the rapid construction of some interesting heterocyclic ring systems. Keywords: carbene, dialkoxycarbene, vinylogous dialkoxycarbene, heterocycle.

scholarly journals Synthesis and characterization of some new heterocyclic compounds from α, β- unsaturated carbonyl system

2021 ◽  
pp. 56-63
Author(s):  
Muna A. Othman Salem ◽  
Hana A. A. Mageed ◽  
Huda S. Muftah ◽  
Reda F. El- Ezabi ◽  
Fayrouz A. Khaled
Keyword(s):  
Heterocyclic Compounds ◽  
Heterocyclic Ring ◽  
Solvent Free ◽  
Synthesis And Characterization ◽  
One Pot ◽  
Ring Systems ◽  
One Pot Synthesis ◽  
Solvent Free Conditions

An efficient and facile one pot synthesis of 3,4-dihydropyrimidinones (Belinelli compound) from furfural, acetylacetone and urea under solvent free conditions was performed, resulted in promising yield. These compounds reacted with benzaldehyde and furfural to give the corresponding chalcones. Chalcones are used to synthesize several derivatives like pyrazolines isoxazoles and pyrimidines having different heterocyclic ring systems. Keywords: Belinelli compounds; Chalcone; Pyrazolines isoxazoles; Pyrimidines

Reactions of alkoxyaryloxycarbenes with tethered triple bonds: a new synthesis of substituted benzofurans

1997 ◽  
Vol 75 (9) ◽  
pp. 1256-1263 ◽  
Author(s):  
Karim Kassam ◽  
Paul C. Venneri ◽  
John Warkentin
Keyword(s):  
High Temperatures ◽  
Intramolecular Cyclization ◽  
Triple Bond ◽  
Triple Bonds ◽  
New Synthesis ◽  
Ketene Acetal

Cyclic 3-alkoxy-3-aryloxyvinylcarbenes can be generated by a highly exo-selective intramolecular cyclization of a dioxycarbene onto a tethered triple bond. Like their dialkoxy counterparts, the 3-alkoxy-3-aryloxyvinylcarbene intermediates are capable of interesting reactions. In contrast to 3,3-dialkoxyvinylcarbenes, which undergo a formal [3 + 2] cycloaddition with highly electron-deficient olefins such as benzylidenemalononitrile, 3-alkoxy-3-aryloxyvinylcarbenes undergo a highly diastereoselective [1 + 2] cycloaddition with benzylidenemalononitrile to give cyclopropylketene acetals. At high temperatures, those cyclopropylketene acetals undergo a clean vinylcyclopropane rearrangement in which the stereochemical integrity of the cyclopropane is retained. Keywords: carbene, alkoxyaryloxy, [1 + 2] cycloaddition, ketene acetal, vinylcyclopropane rearrangement, oxadiazoline.

Recent advances in synthesis and reactions of β-amino-α,β-enones (enaminones)

2021 ◽  
Vol 18 ◽  
Author(s):  
Thoraya Farghaly ◽  
Alaa M. Abo Alnaja ◽  
Mohamed R. Shaaban
Keyword(s):  
Carbonyl Compounds ◽  
Heterocyclic Compounds ◽  
Heterocyclic Ring ◽  
Ring Systems ◽  
Organic Syntheses ◽  
Recent Advances ◽  
Synthetic Routes

Abstract: β-Amino-α,β-enones or β-enamino carbonyl compounds are versatile synthons intermediates for the construction of various bio-active heterocyclic compounds and have been established as multipurpose synthetic precursors in organic syntheses and in pharmaceutical developments. In this work, we will discuss the different synthetic routes to obtain β-Amino-α,β-enones or β-enamino carbonyl compounds, their reactions, and their utility in the construction of organic frameworks and heterocyclic ring systems. Structurally, β-amino-α,β-enones are attractive intermediates that syndicate the ambident behaviours of nucleophilicity and electrophilicity of enones simultaneously. β-amino-α,β-enones have been known as acceptors in both 1,2- and 1,4- additions, which make them good intermediate compounds for annulation to different heterocycles.

1,4-Dihydropyridine: A Dependable Heterocyclic Ring with the Promising and the Most Anticipable Therapeutic Effects

2019 ◽  
Vol 19 (15) ◽  
pp. 1219-1254 ◽  
Author(s):  
Abhinav Prasoon Mishra ◽  
Ankit Bajpai ◽  
Awani Kumar Rai
Keyword(s):  
Calcium Ion ◽  
Heterocyclic Compounds ◽  
Channel Blocker ◽  
Heterocyclic Ring ◽  
Therapeutic Effects ◽  
Voltage Gated ◽  
Therapeutic Benefits ◽  
Anti Cancer ◽  
Anti Oxidant ◽  
Synthetic Medicinal

: Nowadays, heterocyclic compounds act as a scaffold and are the backbone of medicinal chemistry. Among all of the heterocyclic scaffolds, 1,4-Dihydropyridine (1,4-DHP) is one of the most important heterocyclic rings that possess prominent therapeutic effects in a very versatile manner and plays an important role in synthetic, medicinal, and bioorganic chemistry. The main aim of the study is to review and encompass relevant studies related to 1,4-DHP and excellent therapeutic benefits of its derivatives. An extensive review of Pubmed-Medline, Embase and Lancet’s published articles was done to find all relevant studies on the activity of 1,4-DHP and its derivatives. 1,4-DHP is a potent Voltage-Gated Calcium Channel (VGCC) antagonist derivative which acts as an anti-hypertensive, anti- anginal, anti-tumor, anti-inflammatory, anti-tubercular, anti-cancer, anti-hyperplasia, anti-mutagenic, anti-dyslipidemic, and anti-ulcer agent. From the inferences of the study, it can be concluded that the basic nucleus, 1,4-DHP which is a voltage-gated calcium ion channel blocker, acts as a base for its derivatives that possess different important therapeutic effects. There is a need of further research of this basic nucleus as it is a multifunctional moiety, on which addition of different groups can yield a better drug for its other activities such as anti-convulsant, anti-oxidant, anti-mutagenic, and anti-microbial. This review would be significant for further researches in the development of several kinds of drugs by representing successful matrix for the medicinal agents.

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