ChemInform Abstract: Natural Products Containing Medium-Sized Nitrogen Heterocycles Synthesized by Ring-Closing Alkene Metathesis

ChemInform ◽  
2011 ◽  
Vol 42 (17) ◽  
pp. no-no
Author(s):  
Sebastiaan A. M. W. van den Broek ◽  
Silvie A. Meeuwissen ◽  
Floris L. van Delft ◽  
Floris P. J. T. Rutjes
Keyword(s):  
Natural Products ◽  
Nitrogen Heterocycles

scholarly journals Recent applications of imines as key intermediates in the synthesis of alkaloids and novel nitrogen heterocycles

2009 ◽  
Vol 81 (2) ◽  
pp. 195-204 ◽  
Author(s):  
Stephen F. Martin
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Multicomponent Reactions ◽  
Nitrogen Heterocycles ◽  
Biologically Active ◽  
Total Syntheses ◽  
Biological Interest ◽  
Cascade Processes ◽  
Novel Applications ◽  
Active Natural

One of the major challenges in contemporary synthetic organic chemistry is the design and development of new tactics and strategies and their application to concise and efficient syntheses of biologically active natural products. Strategies that utilize reactions that enable the rapid assembly of the skeletal framework of such targets are thus especially attractive. In this context, we have developed novel applications of imine chemistry in Mannich and related reactions, cascade processes, and multicomponent reactions (MCRs) to rapidly assemble structural subunits common to diverse families of alkaloids. The practical utility of these chemistries is evidenced by their use in the execution of facile total syntheses of (±)-epilupinine (1), (±)-tashiromine (2), (-)-epimyrtine (3), and (±)-roelactamine (4) as well as other nitrogen heterocycles of potential biological interest.

Natural Products Containing Medium-Sized Nitrogen Heterocycles Synthesized by Ring-Closing Alkene Metathesis

2010 ◽  
pp. 45-85 ◽  
Author(s):  
Sebastiaan Bas A. M. W. van den Broek ◽  
Silvie A. Meeuwissen ◽  
Floris L. van Delft ◽  
Floris P. J. T. Rutjes
Keyword(s):  
Natural Products ◽  
Nitrogen Heterocycles

scholarly journals Marine Pyrrole Alkaloids

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 514
Author(s):  
Kevin Seipp ◽  
Leander Geske ◽  
Till Opatz
Keyword(s):  
Natural Products ◽  
Chemical Synthesis ◽  
Marine Environment ◽  
Biological Activities ◽  
Nitrogen Heterocycles ◽  
Important Class ◽  
Chemical Machinery ◽  
Terrestrial Habitats ◽  
Pyrrole Alkaloids ◽  
Broad Overview

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.

scholarly journals Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

2017 ◽  
Vol 13 ◽  
pp. 1670-1692 ◽  
Author(s):  
Santanu Hati ◽  
Ulrike Holzgrabe ◽  
Subhabrata Sen
Keyword(s):  
Natural Products ◽  
Oxidative Dehydrogenation ◽  
Scientific Community ◽  
Nitrogen Heterocycles ◽  
Building Blocks ◽  
Important Class ◽  
Heteroaromatic Compounds ◽  
Synthetic Drugs ◽  
Convenient Approach ◽  
Synthetic Drug

Nitrogen heteroarenes form an important class of compounds which can be found in natural products, synthetic drugs, building blocks etc. Among the diverse strategies that were developed for the synthesis of nitrogen heterocycles, oxidative dehydrogenation is extremely effective. This review discusses various oxidative dehydrogenation strategies of C–C and C–N bonds to generate nitrogen heteroarenes from their corresponding heterocyclic substrates. The strategies are categorized under stoichiometric and catalytic usage of reagents that facilitate such transformations. The application of these strategies in the synthesis of nitrogen heteroarene natural products and synthetic drug intermediates are also discussed. We hope this review will arouse sufficient interest among the scientific community to further advance the application of oxidative dehydrogenation in the synthesis of nitrogen heteroarenes.

scholarly journals [3+2] Cycloadditions: Part XXXV. Selective Cycloadditions of C-(4-Chlorophenyl)-N-methyl Nitrone to Cinnamic Acid Anilides

2020 ◽  
Vol 32 (8) ◽  
pp. 1886-1894
Author(s):  
Sumana Sengupta ◽  
Avijit Banerji ◽  
Thierry Prangé ◽  
Alain Neuman ◽  
Jayram Hazra
Keyword(s):  
Natural Products ◽  
Bioactive Compounds ◽  
Cinnamic Acid ◽  
Nitrogen Heterocycles ◽  
Xrd Analysis ◽  
Chemical Transformations ◽  
Nmr Studies ◽  
Naturally Occurring ◽  
Acid Anilides

[3+2] Cycloadditions of nitrones as three-atom components to alkenes yield isoxazolidine cycloadducts, which on chemical transformations can be converted to bioactive compounds. The [3+2] cycloadditions route thus provides conversion of simple natural products to more complex naturally occurring bioactive nitrogen heterocycles, and close analogues. As α,β-unsaturated amides abundantly occur as natural products, [3+2] cycloadditions of nitrones with simpler α,β-unsaturated amides were studied to get information about reactivity profiles. The reactions of C-(4-chlorophenyl)-N-methyl nitrone as three-atom component to cinnamic acid anilides were investigated. The 3,4-trans-4,5-trans-4- carboxanilido-2-methyl-3,5-diaryl isoxazolidines were the major cycloadducts; the diastereoisomeric 3,4-cis-4,5-trans-4-carboxanilido-2-methyl-3,5-diaryl isoxazolidines and regioisomeric 3,4-trans-4,5- trans-5-carboxanilido-2-methyl-3,4-diaryl isoxazolidines were obtained as minor cycloadducts. The cycloadducts were characterized by NMR studies and XRD analysis.

Ring-closing metathesis: A facile construct for alkaloid synthesis

2005 ◽  
Vol 77 (7) ◽  
pp. 1207-1212 ◽  
Author(s):  
Stephen F. Martin
Keyword(s):  
Natural Products ◽  
Case Studies ◽  
Nitrogen Heterocycles ◽  
Ring System ◽  
Facile Synthesis ◽  
Ring Closing Metathesis ◽  
Alkaloid Synthesis ◽  
Highly Effective ◽  
Enantioselective Syntheses ◽  
Effective Reaction

Ring-closing metathesis has been found to be a highly effective reaction for the synthesis of functionalized, bridged nitrogen heterocycles. The utility of the process has been established in several case studies, including a facile synthesis of the tropane ring system and efficient, enantioselective syntheses of the natural products (–)-peduncularine and (+)-anatoxin-a.

scholarly journals Copper catalyzed late-stage C(sp3)-H functionalization of nitrogen heterocycles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhe Chang ◽  
Jialin Huang ◽  
Si Wang ◽  
Geshuyi Chen ◽  
Heng Zhao ◽  
...  
Keyword(s):  
Natural Products ◽  
Chemical Synthesis ◽  
Late Stage ◽  
Nitrogen Heterocycles ◽  
Pharmaceutical Chemistry ◽  
Nitrogen Heterocycle ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Bond Functionalization ◽  
Modern Chemical

AbstractNitrogen heterocycle represents a ubiquitous skeleton in natural products and drugs. Late-stage C(sp3)-H bond functionalization of N-heterocycles with broad substrate scope remains a challenge and of particular significance to modern chemical synthesis and pharmaceutical chemistry. Here, we demonstrate copper-catalysed late-stage C(sp3)-H functionalizaion of N-heterocycles using commercially available catalysts under mild reaction conditions. We have investigated 8 types of N-heterocycles which are usually found as medicinally important skeletons. The scope and utility of this approach are demonstrated by late-stage C(sp3)-H modification of these heterocycles including a number of pharmaceuticals with a broad range of nucleophiles, e.g. methylation, arylation, azidination, mono-deuteration and glycoconjugation etc. Preliminary mechanistic studies reveal that the reaction undergoes a C-H fluorination process which is followed by a nucleophilic substitution.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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