scholarly journals Unified divergent strategy towards the total synthesis of the three sub-classes of hasubanan alkaloids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guang Li ◽  
Qian Wang ◽  
Jieping Zhu
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Michael Addition ◽  
Total Syntheses ◽  
Bond Forming ◽  
The Past ◽  
Tricyclic Compounds

AbstractElegant asymmetric synthesis of hasubanan alkaloids have been developed over the past decades. However, a divergent approach leading to all three sub-classes of this family of natural products remains unknown. We report herein the realization of such an endeavor by accomplishing enantioselective total syntheses of four representative members. The synthesis is characterized by catalytic enantioselective construction of the tricyclic compounds from which three different intramolecular C-N bond forming processes leading to three topologically different hasubanan alkaloids are developed. An aza-Michael addition is used for the construction of the aza-[4.4.3]-propellane structure of (-)-cepharamine, whereas an oxidation/double deprotection/intramolecular hemiaminal forming sequence is developed to forge the bridged 6/6/6/6 tetracycle of (-)-cepharatines A and C and a domino bromination/double deprotection/cyclization sequence allows the build-up of the 6/6/5/5 fused tetracyclic structure of (−)-sinoracutine.

scholarly journals α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

2021 ◽  
Vol 17 ◽  
pp. 2570-2584
Author(s):  
Scott Benz ◽  
Andrew S Murkin
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Hydroxy Group ◽  
Tandem Reactions ◽  
Aryl Group ◽  
The Past

In the presence of a suitable acid or base, α-hydroxyaldehydes, ketones, and imines can undergo isomerization that features the 1,2-shift of an alkyl or aryl group. In the process, the hydroxy group is converted to a carbonyl and the aldehyde/ketone or imine is converted to an alcohol or amine. Such α-ketol/α-iminol rearrangements are used in a wide variety of synthetic applications including asymmetric synthesis, tandem reactions, and the total synthesis and biosynthesis of natural products. This review explores the use of α-ketol rearrangements in these contexts over the past two decades.

Enantioselective Syntheses of Yohimbine Alkaloids: Proving Grounds for New Catalytic Transformations

Synthesis ◽  
2021 ◽  
Author(s):  
Karl A. Scheidt ◽  
Eric R Miller
Keyword(s):  
Natural Products ◽  
Chemical Synthesis ◽  
Total Synthesis ◽  
State Of The Art ◽  
The State ◽  
Catalytic Transformations ◽  
Bond Forming ◽  
The Past ◽  
Catalytic Asymmetric ◽  
Enantioselective Syntheses

The total synthesis of bioactive alkaloids is an enduring challenge and an indication of the state of the art of chemical synthesis. With the explosion of catalytic asymmetric methods over the past three decades, these compelling targets have been fertile proving grounds for enantioselective bond forming transformations. We summarize these activities herein both to highlight the power and versatility of these methods and to instill future inspiration for new syntheses of these privileged natural products.

scholarly journals Concise total syntheses of (–)-jorunnamycin A and (–)-jorumycin enabled by asymmetric catalysis

Science ◽  
2018 ◽  
Vol 363 (6424) ◽  
pp. 270-275 ◽  
Author(s):  
Eric R. Welin ◽  
Aurapat Ngamnithiporn ◽  
Max Klatte ◽  
Guillaume Lapointe ◽  
Gerit M. Pototschnig ◽  
...  
Keyword(s):  
Natural Products ◽  
Asymmetric Catalysis ◽  
High Efficiency ◽  
Transition Metal Catalysis ◽  
Metal Catalysis ◽  
Polycyclic Compounds ◽  
Gram Negative ◽  
Total Syntheses ◽  
Bond Forming ◽  
The Past

The bis-tetrahydroisoquinoline (bis-THIQ) natural products have been studied intensively over the past four decades for their exceptionally potent anticancer activity, in addition to strong Gram-positive and Gram-negative antibiotic character. Synthetic strategies toward these complex polycyclic compounds have relied heavily on electrophilic aromatic chemistry, such as the Pictet–Spengler reaction, that mimics their biosynthetic pathways. Herein, we report an approach to two bis-THIQ natural products, jorunnamycin A and jorumycin, that instead harnesses the power of modern transition-metal catalysis for the three major bond-forming events and proceeds with high efficiency (15 and 16 steps, respectively). By breaking from biomimicry, this strategy allows for the preparation of a more diverse set of nonnatural analogs.

scholarly journals Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 249
Author(s):  
Raquel G. Soengas ◽  
Humberto Rodríguez-Solla
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Group ◽  
Biological Activities ◽  
Synthetic Methods ◽  
Bond Forming ◽  
Drug Candidates ◽  
The Past ◽  
Wide Range

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

scholarly journals Heronapyrrole D: A case of co-inspiration of natural product biosynthesis, total synthesis and biodiscovery

2014 ◽  
Vol 10 ◽  
pp. 1228-1232 ◽  
Author(s):  
Jens Schmidt ◽  
Zeinab Khalil ◽  
Robert J Capon ◽  
Christian B W Stark
Keyword(s):  
Antibacterial Activity ◽  
Natural Products ◽  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Natural Product ◽  
Joint Effort ◽  
Natural Product Biosynthesis ◽  
New Members ◽  
Degree Of Oxidation ◽  
Rare Class

The heronapyrroles A–C have first been isolated from a marine-derived Streptomyces sp. (CMB-0423) in 2010. Structurally, these natural products feature an unusual nitropyrrole system to which a partially oxidized farnesyl chain is attached. The varying degree of oxidation of the sesquiterpenyl subunit in heronapyrroles A–C provoked the hypothesis that there might exist other hitherto unidentified metabolites. On biosynthetic grounds a mono-tetrahydrofuran-diol named heronapyrrole D appeared a possible candidate. We here describe a short asymmetric synthesis of heronapyrrole D, its detection in cultivations of CMB-0423 and finally the evaluation of its antibacterial activity. We thus demonstrate that biosynthetic considerations and the joint effort of synthetic and natural product chemists can result in the identification of new members of a rare class of natural products.

Total synthesis of the potent antifungal agents bengazole C and E

2009 ◽  
Vol 74 (6) ◽  
pp. 887-900 ◽  
Author(s):  
Álvaro Enríquez-García ◽  
Steven V. Ley
Keyword(s):  
Natural Products ◽  
Antifungal Activity ◽  
Total Synthesis ◽  
Marine Natural Products ◽  
Antifungal Agents ◽  
Nitrile Oxide ◽  
Total Syntheses ◽  
Unique Structure

The bengazoles are marine natural products with unique structure, containing two oxazole rings flanking a single carbon. They show very potent antifungal activity. The total syntheses of bengazole C and E are described following a convergent route which involves diastereoselective cycloaddition of an appropriately substituted nitrile oxide with a butane-1,2-diacetal-protected alkenediol as the key step.

Aryne-based strategy in the total synthesis of naturally occurring polycyclic compounds

2018 ◽  
Vol 47 (21) ◽  
pp. 8030-8056 ◽  
Author(s):  
Hiroshi Takikawa ◽  
Arata Nishii ◽  
Takahiro Sakai ◽  
Keisuke Suzuki
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Polycyclic Compounds ◽  
Total Syntheses ◽  
Naturally Occurring

This review has outlined the strategies and tactics of using arynes in the total syntheses of polycyclic natural products.

scholarly journals Contiguous Quaternary Carbons: A Selection of Total Syntheses

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3841
Author(s):  
Alina Eggert ◽  
Christoph Etling ◽  
Dennis Lübken ◽  
Marius Saxarra ◽  
Markus Kalesse
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Status Quo ◽  
Total Syntheses ◽  
The Status ◽  
Selection Of ◽  
Quaternary Carbons

Contiguous quaternary carbons in terpene natural products remain a major challenge in total synthesis. Synthetic strategies to overcome this challenge will be a pivotal prerequisite to the medicinal application of natural products and their analogs or derivatives. In this review, we cover syntheses of natural products that exhibit a dense assembly of quaternary carbons and whose syntheses were uncompleted until recently. While discussing their syntheses, we not only cover the most recent total syntheses but also provide an update on the status quo of modern syntheses of complex natural products. Herein, we review (±)-canataxpropellane, (+)-waihoensene, (–)-illisimonin A and (±)-11-O-debenzoyltashironin as prominent examples of natural products bearing contiguous quaternary carbons.

Construction of sulfur-containing moieties in the total synthesis of natural products

2020 ◽  
Vol 37 (2) ◽  
pp. 246-275 ◽  
Author(s):  
Nengzhong Wang ◽  
Puli Saidhareddy ◽  
Xuefeng Jiang
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Total Syntheses ◽  
Sulfur Containing

This review surveys the total syntheses of sulfur-containing natural products where sulfur atoms are introduced with different sulfurization agents to construct related sulfur-containing moieties.

scholarly journals Strategies and Efforts towards the Total Synthesis of Palhinine Alkaloids

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4211
Author(s):  
Yu-Yan Liang ◽  
Shi-Chao Lu ◽  
Ya-Ling Gong ◽  
Shu Xu
Keyword(s):  
Total Synthesis ◽  
Review Article ◽  
Research Groups ◽  
Asymmetric Total Synthesis ◽  
Carbon Cage ◽  
Total Syntheses ◽  
The Past ◽  
Lycopodium Alkaloids

The palhinine family of Lycopodium alkaloids were first reported in 2010, which feature an intriguing isotwistane carbon cage and a nine-membered azonane ring. It is noteworthy that the tetracyclic 5/6/6/9 skeleton was unprecedented in Lycopodium alkaloids before their seminal discovery. Over the past decade, extensive synthetic efforts stemming from seven research groups have resulted in two racemic total syntheses to date. This review article takes the opportunity to survey these efforts and achievements so as to promote further research towards the asymmetric total synthesis of palhinine alkaloids.

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