The [4.3.0] piperidine alkaloids: architectures, biology, biosyntheses and the complete details of the asymmetric syntheses of streptazone A and abikoviromycin

Synlett ◽  
2021 ◽  
Author(s):  
Gustav J. Wørmer ◽  
Thomas Bjørnskov Poulsen
Keyword(s):  
Natural Products ◽  
Biological Properties ◽  
Piperidine Alkaloids ◽  
Complete Coverage ◽  
Asymmetric Syntheses ◽  
Concise Overview ◽  
Michael Acceptors

Piperidine alkaloids continue to challenge the synthetic community by featuring densely functionalized scaffolds which often requires careful chemical orchestration. Streptazone A and abikoviromycin are small and highly functionalized piperidine alkaloids both accommodating Michael acceptors and a labile epoxide. These moieties are loaded into a [4.3.0] bicyclic core also present in other structurally related natural products including the well-known piperidine alkaloid streptazolin. Herein, we cover ring-closing strategies employed in prior streptazolin syntheses, provide a concise overview of structures, biological properties and biosyntheses of selected [4.3.0] piperidine alkaloids, and finally we disclose a complete coverage of our recent asymmetric syntheses of streptazone A and abikoviromycin.

Enantioselective Syntheses of Flavonoid Diels-Alder Natural Products: A Review

2018 ◽  
Vol 15 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Shah Bakhtiar Nasir ◽  
Noorsaadah Abd Rahman ◽  
Chin Fei Chee
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Enantioselective Synthesis ◽  
Chiral Ligand ◽  
Asymmetric Syntheses ◽  
Diels Alder Reaction ◽  
Enantioselective Syntheses

Background: The Diels-Alder reaction has been widely utilised in the syntheses of biologically important natural products over the years and continues to greatly impact modern synthetic methodology. Recent discovery of chiral organocatalysts, auxiliaries and ligands in organic synthesis has paved the way for their application in Diels-Alder chemistry with the goal to improve efficiency as well as stereochemistry. Objective: The review focuses on asymmetric syntheses of flavonoid Diels-Alder natural products that utilize chiral ligand-Lewis acid complexes through various illustrative examples. Conclusion: It is clear from the review that a significant amount of research has been done investigating various types of catalysts and chiral ligand-Lewis acid complexes for the enantioselective synthesis of flavonoid Diels-Alder natural products. The results have demonstrated improved yield and enantioselectivity. Much emphasis has been placed on the synthesis but important mechanistic work aimed at understanding the enantioselectivity has also been discussed.

Synthesis of new cyclopeptide analogues of the miuraenamides

2021 ◽  
Vol 18 ◽  
Author(s):  
Sarah Kappler ◽  
Andreas Siebert ◽  
Uli Kazmaier
Keyword(s):  
Natural Products ◽  
Biological Properties ◽  
Amide Bond ◽  
Side Chain ◽  
Aromatic Side Chain ◽  
Highly Active ◽  
C Terminus ◽  
Terminal Amino ◽  
High Cytotoxicity ◽  
Derivatives Of

Introduction: Miuraenamides belong to marine natural compounds with interesting biological properties. Materials and Methods: They initiate polymerization of monomeric actin and therefore show high cytotoxicity by influencing the cytoskeleton. New derivatives of the miuraenamides have been synthesized containing a N-methylated amide bond instead of the more easily hydrolysable ester in the natural products. Results: Incorporation of an aromatic side chain onto the C-terminal amino acid of the tripeptide fragment also led to highly active new miuraenamides. Conclusion: We could show that the ester bond of the natural product miuraenamide can be replaced by an N-methyl amide. The yields in the cyclization step are high and generally much better that with the corresponding esters. On the other hand, the biological activity of the new amide analogs are lower compared to the natural products, but the activity can significantly be increased by incorporation of a p-nitrophenyl group at the C-terminus of the peptide fragment.

scholarly journals Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

2020 ◽  
Vol 16 ◽  
pp. 212-232 ◽  
Author(s):  
Delphine Pichon ◽  
Jennifer Morvan ◽  
Christophe Crévisy ◽  
Marc Mauduit
Keyword(s):  
Natural Products ◽  
Conjugate Addition ◽  
Catalytic Transformation ◽  
Chiral Molecules ◽  
Catalytic Systems ◽  
Organometallic Reagents ◽  
Recent Advances ◽  
Wide Range ◽  
Michael Acceptors

The copper-catalyzed enantioselective conjugate addition (ECA) of organometallic nucleophiles to electron-deficient alkenes (Michael acceptors) represents an efficient and attractive methodology for providing a wide range of relevant chiral molecules. In order to increase the attractiveness of this useful catalytic transformation, some Michael acceptors bearing challenging electron-deficient functions (i.e., aldehydes, thioesters, acylimidazoles, N-acyloxazolidinones, N-acylpyrrolidinones, amides, N-acylpyrroles) were recently investigated. Remarkably, only a few chiral copper-based catalytic systems have successfully achieved the conjugate addition of different organometallic reagents to these challenging Michael acceptors, with excellent regio- and enantioselectivity. Furthermore, thanks to their easy derivatization, the resulting chiral conjugated products could be converted into various natural products. The aim of this tutorial review is to summarize recent advances accomplished in this stimulating field.

scholarly journals Special Issue: The Antioxidant Capacities of Natural Products

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 492 ◽  
Author(s):  
Susana Cardoso
Keyword(s):  
Oxidative Stress ◽  
Natural Products ◽  
Biological Properties ◽  
Industrial Applications ◽  
Special Issue ◽  
Antioxidant Capacities

Antioxidants are under the research spotlight because of their potential to prevent oxidative stress as well as for their versatile biological properties that grant them multiple industrial applications [...]

Asymmetric syntheses of epohelmins A and B by In-mediated allylation

2016 ◽  
Vol 14 (45) ◽  
pp. 10714-10722 ◽  
Author(s):  
Yi-Wen Liu ◽  
Pan Han ◽  
Wen Zhou ◽  
Zhuo-Ya Mao ◽  
Chang-Mei Si ◽  
...  
Keyword(s):  
Natural Products ◽  
Allyl Bromide ◽  
Asymmetric Syntheses

Natural products epohelmins A and B have been asymmetrically synthesized by In-mediated allylation of α-chiral aldimine with allyl bromide.

Arabinosylamine in Asymmetric Syntheses of Chiral Piperidine Alkaloids.

ChemInform ◽  
2004 ◽  
Vol 35 (31) ◽  
Author(s):  
Birgit Kranke ◽  
Dominique Hebrault ◽  
Martin Schultz-Kukula ◽  
Horst Kunz
Keyword(s):  
Piperidine Alkaloids ◽  
Asymmetric Syntheses

Arabinosylamine in Asymmetric Syntheses of Chiral Piperidine Alkaloids

Synlett ◽  
2004 ◽  
pp. 671-674
Author(s):  
Horst Kunz ◽  
Birgit Kranke ◽  
Dominique Hebrault ◽  
Martin Schultz-Kukula
Keyword(s):  
Piperidine Alkaloids ◽  
Asymmetric Syntheses

scholarly journals Asymmetric Syntheses of the Flavonoid Diels–Alder Natural Products Sanggenons C and O

2016 ◽  
Vol 138 (3) ◽  
pp. 798-801 ◽  
Author(s):  
Chao Qi ◽  
Yuan Xiong ◽  
Vincent Eschenbrenner-Lux ◽  
Huan Cong ◽  
John A. Porco
Keyword(s):  
Natural Products ◽  
Diels Alder ◽  
Asymmetric Syntheses
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