Search results for "Nitrogen heterocycles"
showing 10 items of 16 documents
An overview on the recent developments of 1,2,4-triazine derivatives as anticancer compounds
2017
The synthesis, the antitumor activity, the SAR and, whenever described, the possible mode of action of 1,2,4-triazine derivatives, their N-oxides, N,. N'-dioxides as well as the benzo- and hetero-fused systems are reported. Herein are treated derivatives disclosed to literature from the beginning of this century up to 2016. Among the three possible triazine isomers, 1,2,4-triazines are the most studied ones and many derivatives having remarkable antitumor activity have been reported in the literature and also patented reaching advanced phases of clinical trials.
Synthesis and antitumor activities of 1,2,3-triazines and their benzo- and heterofused derivatives
2017
1,2,3-Triazines are a class of biologically active compounds that exhibit a broad spectrum of activities, including antibacterial, antifungal, antiviral, antiproliferative, analgesic and anti-inflammatory properties. This review, which covers the literature from the end of last century to 2016, treats, through a comprehensive, systematic approach, the 1,2,3-triazine and related benzo- and hetero-fused derivatives possessing antitumor activity. Their efficacy, combined with a simple synthesis confers to these molecules a great potential as scaffold for the development of antitumor compounds.
1,3,5-Triazines: A promising scaffold for anticancer drugs development
2017
This review covering literature reports from the beginning of this century to 2016 describes the synthetic pathways, the antitumor activity, the structure-activity relationship and, whenever reported, the possible mechanism of action of 1,3,5-triazine derivatives as well as of their hetero-fused compounds. Many 1,3,5-triazine derivatives, both uncondensed and hetero-fused, have shown remarkable antitumor activities and some of them reached clinical development.
Marine Indole Alkaloids.
2015
Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed.
Marine Pyrrole Alkaloids
2021
Nitrogen heterocycles are essential parts of the chemical machinery of life and often reveal intriguing structures. They are not only widespread in terrestrial habitats but can also frequently be found as natural products in the marine environment. This review highlights the important class of marine pyrrole alkaloids, well-known for their diverse biological activities. A broad overview of the marine pyrrole alkaloids with a focus on their isolation, biological activities, chemical synthesis, and derivatization covering the decade from 2010 to 2020 is provided. With relevant structural subclasses categorized, this review shall provide a clear and timely synopsis of this area.
Synthesis of Fluorinated and Non-Fluorinated Bicyclic Amidines through Ring-Closing Metathesis
2011
[EN] An efficient method for the synthesis of fluorinated and non-fluorinated imidazoazepines by a ring-closing metathesis reaction as the key step is described. The influence of the fluorine atoms on the preparation of these bicyclic systems is also studied.
1,2,3-Triazole in Heterocyclic Compounds, Endowed with Biological Activity, through 1,3-Dipolar Cycloadditions
2014
1,3-Dipolar cycloaddition reactions can be considered a powerful synthetic tool in the building of heterocyclic rings, with applications in different fields. In this review we focus on the synthesis of biologically active compounds possessing the 1,2,3-triazole core through 1,3-dipolar cycloaddition reactions. The 1,2,3-triazole skeleton can be present as a single disubstituted ring, as a linker between two molecules, or embedded in a polyheterocycle. The cycloaddition reactions are usually catalysed by copper or ruthenium. Domino reactions can be achieved through dipolarophile anion formation, generally followed by cyclisation. The variety of attainable heterocyclic structures gives an ill…
Catalytic Asymmetric Formal [3+2] Cycloaddition of 2-Isocyanatomalonate Esters and Unsaturated Imines: Synthesis of Highly Substituted Chiral γ-Lacta…
2017
[EN] Unlike their isocyano and isothiocyanato analogues, isocyanato esters remain almost unexplored as formal 1,3-dipoles in asymmetric catalytic reactions. The first asymmetric formal [3+2] cycloaddition involving isocyanato esters and electrophilic alkenes is reported. Diisopropyl 2-isocyanatomalonate reacts with a,b-unsaturated N-(o-anisidyl) imines in the presence of a Mg(OTf)2¿BOX complex to give highly substituted chiral pyrrolidinones featuring a conjugate exocyclic double bond with excellent yields and enantiomeric excesses up to 99%. Several transformations of the resulting heterocycles, including the synthesis of a pyroglutamic acid derivative, have been carried out.
Selective and Scalable Electrosynthesis of 2H-2-(Aryl)-benzo[d]-1,2,3-triazoles and Their N-Oxides by Using Leaded Bronze Cathodes.
2020
Abstract Electrosynthesis of 2H‐2‐(aryl)benzo[d]‐1,2,3‐triazoles and their N‐oxides from 2‐nitroazobenzene derivatives is reported. The electrolysis is conducted in a very simple undivided cell under constant current conditions with a leaded bronze cathode and a glassy carbon anode. The product distribution between 2H‐2‐(aryl)benzo[d]‐1,2,3‐triazoles and their N‐oxides can be guided by simply controlling the current density and the amount of the charge applied. The reaction tolerates several sensitive functional groups in reductive electrochemistry. The usefulness and the applicability of the synthetic method is demonstrated by a formal synthesis of an antiviral compound.
A Domino Ring‐Closure Followed by Retro‐Diels–Alder Reaction for the Preparation of Pyrimido[2,1‐ a ]isoindole Enantiomers
2016
A simple method was developed to prepare pyrimido[2,1-a]isoindole derivatives by using di-endo- and di-exo-ethyl 3-aminobicyclo[2.2.1]hept-5-ene-2-carboxylate enantiomers as chiral sources. The method is based on a domino ring-closure reaction of norbornene 2-aminohydroxamic acid followed by microwave-induced retro-Diels–Alder reaction. In the case of enantiomeric starting substances, the chirality is transferred from norbornene derivatives to pyrimido[2,1-a]isoindoles. The configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy [based on 2D NOE cross-peaks and 3JH,H coupling constants] and X-ray crystallography.