scholarly journals Cross-Coupling as a Key Step in the Synthesis and Structure Revision of the Natural Products Selagibenzophenones A and B

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 708
Author(s):  
Ringaile Lapinskaite ◽  
Štefan Malatinec ◽  
Miguel Mateus ◽  
Lukas Rycek
Keyword(s):  
Natural Products ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Biologically Active ◽  
Substitution Pattern ◽  
Partial Control ◽  
Total Syntheses ◽  
Synthetic Strategy ◽  
Methoxy Groups ◽  
Reported Data

Selagibenzophenone A (1) and its isomer selagibenzophenone B (2) were recently described as natural products from Selaginella genus plants with PDE4 inhibitory activity. Herein, we report the first total syntheses of both compounds. By comparing spectroscopic data of the synthetic compounds with reported data for the isolated material, we demonstrate that the structure of one of the two natural products was incorrectly assigned, and that in fact isolated selagibenzophenone A and selagibenzophenone B are identical compounds. The synthetic strategy for both 1 and 2 is based on a cross-coupling reaction and on the addition of organometallic species to assemble the framework of the molecules. Identifying a suitable starting material with the correct substitution pattern is crucial because its pattern is reflected in that of the targeted compounds. These syntheses are finalized via global deprotection. Protecting the phenols as methoxy groups provides the possibility for partial control over the selectivity in the demethylation thanks to differences in the reactivity of the various methoxy groups. Our findings may help in future syntheses of derivatives of the biologically active natural product and in understanding the structure–activity relationship.

Chemoselective reactions: Toward the synthesis of biologically active natural products with anticancer activities

2008 ◽  
Vol 80 (8) ◽  
pp. 1683-1691 ◽  
Author(s):  
Sébastien Reymond ◽  
Laurent Ferrié ◽  
Amandine Guérinot ◽  
Patrice Capdevielle ◽  
Janine Cossy
Keyword(s):  
Natural Products ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Biologically Active ◽  
Synthetic Approach ◽  
Anticancer Activities ◽  
Leucascandrolide A ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
Active Natural

Leucascandrolide A and migrastatin were synthesized efficiently by using chemoselective reactions such as olefin metatheses. The use of an iron-catalyzed cross-coupling reaction overcame difficulties encountered with palladium-catalyzed processes in our synthetic approach toward spirangien A.

Formal Total Syntheses of Crocacin A-D

2005 ◽  
Vol 70 (10) ◽  
pp. 1696-1708 ◽  
Author(s):  
Magnus Besev ◽  
Christof Brehm ◽  
Alois Fürstner
Keyword(s):  
Natural Products ◽  
Aldol Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Total Syntheses ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
The Common ◽  
Selective Addition

A concise route to the common polyketide fragment5of crocacin A-D (1-4) is presented which has previously been converted into all members of this fungicidal and cytotoxic family of dipeptidic natural products by various means. Our synthesis features asyn-selective titanium aldol reaction controlled by a valinol-derived auxiliary, a zinc-mediated, palladium-catalyzedanti-selective addition of propargyl mesylate10to the chiral aldehyde9, as well as a comparison of palladium-catalyzed Stille and Suzuki cross-coupling reactions for the formation of the diene moiety of the target.

The Synthesis of Pharmaceuticals: The Effective Application of Secondary Boronic Esters in Enantioselective Suzuki ‐ Miyaura Cross ‐ Coupling Reactions

2016 ◽  
Author(s):  
Jonathon Moir
Keyword(s):  
Natural Products ◽  
Human Life ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Boronic Esters ◽  
Carbon Carbon Bonds ◽  
Effective Drugs

Pharmaceuticals and drugs have become an indispensable part of human life. Presently, a myriad of different drugs are available for a variety of mental and physical health concersn. The synthesis of these drugs, however, remains an elusive and often difficult aspect of the industry. The importance of chirality, or "handedness", in the synthesis of natural products is paramount, as any given pair of enantiomers can have widely differing physiological effects. As such, the ability to control the enantioselectivity of a reaction is of the utmost importance. One example of a facile method used to form carbon-carbon bonds is the Suzuki-Miyaura cross-coupling reaction. Not only is this reaction effective at coupling primary organoboronic esters with organohalides, but recent work in the Crudden group in the Department of Chemistry has revealed an effective method of also cross-couplingchiral secondary organoboronic esters with good retention of stereochemistry. This work, the first of its kind, is crucial in developing single-handed natural products for a wide array of applications, including applications in the pharmaceutical industry. The end result is safer and more effective drugs for distribution to the general public. To expand the scope of this project, new substrates are currently being synthesized for cross-coupling applications. The overall goal is to improve upon current methodologies, while helping to meet the industrial and academic needs of the future.  

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.

Asymmetric Organocatalytic Syntheses of Bioactive Compounds

2021 ◽  
Vol 18 ◽  
Author(s):  
Estibaliz Sansinenea ◽  
Aurelio Ortiz
Keyword(s):  
Natural Products ◽  
Asymmetric Synthesis ◽  
Bioactive Compounds ◽  
Cascade Reactions ◽  
Biologically Active ◽  
Active Compounds ◽  
Total Syntheses ◽  
Main Structure ◽  
New Methodologies ◽  
High Stereoselectivity

Background: The total syntheses of complex natural products have evolved to include new methodologies to save time, simplifying the form to achieve these natural compounds. Objective: In this review, we have described the asymmetric synthesis of different natural products and biologically active compounds of the last ten years until the current day. Results: An asymmetric organocatalytic reaction is the key to generate stereoselectively the main structure with the required stereochemistry. Conclusion: Even more remarkable, the organocatalytic cascade reactions, which are carried out with high stereoselectivity, as well as a possible approximation of the organocatalysts activation with substrates are also described.

Enantioselective constructions of quaternary carbons and their application to the asymmetric total syntheses of fredericamycin A and discorhabdin A

2007 ◽  
Vol 79 (4) ◽  
pp. 701-713 ◽  
Author(s):  
Yasuyuki Kita ◽  
Hiromichi Fujioka
Keyword(s):  
Natural Products ◽  
Optically Active ◽  
Biologically Active ◽  
Hypervalent Iodine ◽  
Total Syntheses ◽  
Carbon Centers ◽  
Phenol Derivatives ◽  
Fredericamycin A ◽  
Active Natural ◽  
Quaternary Carbons

An efficient enantioselective construction of quaternary carbons including spiro carbons is an area of intense interest due to the importance of these units as components of biologically active natural products. Prominent methods are presented for the synthesis of chiral, nonracemic quaternary carbon centers by (i) stereospecific rearrangement of optically active epoxides, (ii) enzyme-catalyzed resolution, and (iii) hypervalent iodine reagent-induced ipso-substitution of para-substituted phenol derivatives. These methods were applied to the total syntheses of fredericamycin A and discorhabdin A.

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