scholarly journals A Concise Total Synthesis of the Fungal Isoquinoline Alkaloid TMC-120B

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 521
Author(s):  
Ahmad K. Haidar ◽  
Niels D. Kjeldsen ◽  
Nikolaj S. Troelsen ◽  
Viola Previtali ◽  
Kasper P. Lundquist ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Isoquinoline Alkaloid ◽  
Total Syntheses ◽  
Antiepileptic Activity ◽  
Short Synthesis

Recent reports of antiepileptic activity of the fungal alkaloid TMC-120B have renewed the interest in this natural product. Previous total syntheses of TMC-120B comprise many steps and have low overall yields (11–17 steps, 1.5–2.9% yield). Thus, to access this compound more efficiently, we herein present a concise and significantly improved total synthesis of the natural product. Our short synthesis relies on two key cyclization steps to assemble the central scaffold: isoquinoline formation via an ethynyl-imino cyclization and an intramolecular Friedel-Crafts reaction to form the furanone.

A Short Synthesis of (+)-Brefeldin C via Enantioselective Radical Hydroalkynylation

2019 ◽  
Author(s):  
Lars Gnägi ◽  
Severin Vital Martz ◽  
Daniel Meyer ◽  
Robin Marc Schärer ◽  
Philippe Renaud
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Oxidation State ◽  
Single Step ◽  
Radical Process ◽  
Target Molecule ◽  
Short Synthesis ◽  
The One

<div><div><div><div><p>A very concise total synthesis of (+)-brefeldin C starting from 2-furanylcyclopentene is described. This approach is based on an unprecedented enantioselective radical hydroalkynylation process to introduce the two cyclopentane stereocenters in a single step. The use of a furan substituent allows to achieve a high trans diastereoselectivity during the radical process and it contains the four carbon atoms C1–C4 of the natural product in an oxidation state closely related to the one of the target molecule. The eight-step synthesis require six product purifications and it provides (+)-brefeldin C in 18% overall yield.</p></div></div></div></div>

scholarly journals Total Syntheses of Pladienolide-Derived Spliceosome Modulators

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5938
Author(s):  
Jaehoon Sim ◽  
Eunbin Jang ◽  
Hyun Jin Kim ◽  
Hongjun Jeon
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Structural Features ◽  
Synthetic Approach ◽  
Synthetic Analog ◽  
Phase I Clinical Trials ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Anti Cancer ◽  
Synthetic Approaches

Pladienolides, an emerging class of naturally occurring spliceosome modulators, exhibit interesting structural features, such as highly substituted 12-membered macrocycles and epoxide-containing diene side chains. The potential of pladienolides as anti-cancer agents is confirmed by H3B-8800, a synthetic analog of this natural product class, which is currently under Phase I clinical trials. Since its isolation in 2004 and the first total synthesis in 2007, a dozen total syntheses and synthetic approaches toward the pladienolide class have been reported to date. This review focuses on the eight completed total syntheses of naturally occurring pladienolides or their synthetic analogs, in addition to a synthetic approach to the main framework of the natural product.

scholarly journals The Calyciphylline B-type Alkaloids: Total Syntheses of (–)-Daphlongamine H and (–)-Isodaphlongamine H

2019 ◽  
Author(s):  
Cedric Hugelshofer ◽  
Vignesh Palani ◽  
Richmond Sarpong
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Mannich Reaction ◽  
Biosynthetic Pathway ◽  
Total Syntheses ◽  
Diastereoselective Hydrogenation ◽  
Tricyclic Core ◽  
Synthetic Studies

The first total synthesis of the complex hexacylic Daphniphyllum alkaloid (–)-daphlongamine H in enantioenriched form has been accomplished. Key to the success of the strategy are a complexity-building Mannich reaction, efficient cyclizations, and a highly diastereoselective hydrogenation to assemble multigram quantities of the tricyclic core bearing four contiguous stereocenters. Following construction of the hydro-indene substructure by means of a Pauson–Khand reaction, endgame redox manipulations delivered the natural product. Importantly, the synthetic studies have also given access to (–)-isodaphlongamine H and led to a revision of the reported structure of deoxyisocalyciphylline B, which resulted in the proposal of a modified biosynthetic pathway to the calyciphylline B-type alkaloids.

scholarly journals Evolution of Pauson-Khand Reaction: Strategic Applications in Total Syntheses of Architecturally Complex Natural Products (2016–2020)

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1199
Author(s):  
Sijia Chen ◽  
Chongguo Jiang ◽  
Nan Zheng ◽  
Zhen Yang ◽  
Lili Shi
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Organic Synthesis ◽  
Total Syntheses

Metal-mediated cyclizations are important transformations in a natural product total synthesis. The Pauson-Khand reaction, particularly powerful for establishing cyclopentenone-containing structures, is distinguished as one of the most attractive annulation processes routinely employed in synthesis campaigns. This review covers Co, Rh, and Pd catalyzed Pauson-Khand reaction and summarizes its strategic applications in total syntheses of structurally complex natural products in the last five years. Additionally, the hetero-Pauson-Khand reaction in the synthesis of heterocycles will also be discussed. Focusing on the panorama of organic synthesis, this review highlights the strategically developed Pauson-Khand reaction in fulfilling total synthetic tasks and its synthetic attractiveness is aimed to be illustrated.

scholarly journals Total Synthesis of Nine Longiborneol Sesquiterpenoids Using a Functionalized Camphor Strategy

2021 ◽  
Author(s):  
Robert F. Lusi ◽  
Goh Sennari ◽  
Richmond Sarpong
Keyword(s):  
Chemical Synthesis ◽  
Total Synthesis ◽  
Natural Product ◽  
Late Stage ◽  
Strategy Development ◽  
Topological Complexity ◽  
Efficient Synthesis ◽  
Short Synthesis ◽  
Synthesis Routes ◽  
The 1960S

<p>Natural product total synthesis inspires strategy development in chemical synthesis. In the 1960s, Corey and coworkers demonstrated a visionary preparation of the terpenoid longifolene, using “strategic bond analysis” to craft a synthesis route. This approach proposes that efficient synthesis routes to bridged, polycyclic, structures should be formulated to introduce the bulk of the target’s topological complexity at a late stage. In subsequent decades, similar strategies have proved general for the syntheses of a wide variety of bridged, polycyclic molecules. Here, we demonstrate that an orthogonal strategy, which utilizes a topologically complex bicyclo[2.2.1] starting material accessed through a scaffold rearrangement of (<i>S</i>)-carvone, leads to a remarkably short synthesis of the longifolene-related terpenoid longiborneol. We also employ a variety of late-stage C–H functionalization tactics in divergent syntheses of many longiborneol congeners. Our strategy should prove effective for the preparation of other topologically complex natural products that contain the bicyclo[2.2.1] framework.</p>

scholarly journals The Calyciphylline B-type Alkaloids: Total Syntheses of (–)-Daphlongamine H and (–)-Isodaphlongamine H

2019 ◽  
Author(s):  
Cedric Hugelshofer ◽  
Vignesh Palani ◽  
Richmond Sarpong
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Mannich Reaction ◽  
Biosynthetic Pathway ◽  
Total Syntheses ◽  
Diastereoselective Hydrogenation ◽  
Tricyclic Core ◽  
Synthetic Studies

The first total synthesis of the complex hexacylic Daphniphyllum alkaloid (–)-daphlongamine H in enantioenriched form has been accomplished. Key to the success of the strategy are a complexity-building Mannich reaction, efficient cyclizations, and a highly diastereoselective hydrogenation to assemble multigram quantities of the tricyclic core bearing four contiguous stereocenters. Following construction of the hydro-indene substructure by means of a Pauson–Khand reaction, endgame redox manipulations delivered the natural product. Importantly, the synthetic studies have also given access to (–)-isodaphlongamine H and led to a revision of the reported structure of deoxyisocalyciphylline B, which resulted in the proposal of a modified biosynthetic pathway to the calyciphylline B-type alkaloids.

scholarly journals On the Structure of (R)-2-Methylheptyl Isonicotinate: Evidence for the Structural Solution from Total Synthesis

2018 ◽  
Vol 13 (3) ◽  
pp. 1934578X1801300
Author(s):  
Mangala Gowri Ponnapalli ◽  
Narayana Rao Gundoju ◽  
Harikiran Theerthala ◽  
Ramesh Bokam ◽  
Nageswara Rao Yalavarthi
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Molecular Identification ◽  
Total Syntheses ◽  
Ethylhexyl Phthalate ◽  
Microbial Agent ◽  
Structural Solution

The controversial molecular identification of ( R)-2-methylheptyl isonicotinate (1) has been settled. Despite its significance as a potent anti-microbial agent against several clinically relevant pathogens, the structure of natural product is uncertain so far due to controversial reports. Its structure has been resolved as bis (2-ethylhexyl) phthalate (2) by total syntheses of chain isomers. In addition, we have also revised bis (2-methylheptyl) phthalate (3) as (2) in some reports.

Total Synthesis of Natural Products Using Intramolecular Nozaki–Hiyama–Takai–Kishi Reactions

Synlett ◽  
2020 ◽  
Vol 31 (05) ◽  
pp. 421-433 ◽  
Author(s):  
Ken-ichi Takao ◽  
Akihiro Ogura ◽  
Keisuke Yoshida ◽  
Siro Simizu
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Natural Product Synthesis ◽  
Total Syntheses

In this Account, we describe our studies on the total synthesis of several natural products using intramolecular Nozaki–Hiyama–Takai–Kishi (NHTK) reactions. In each synthesis, an NHTK reaction is used to efficiently construct a medium-sized ring. These examples demonstrate the utility of the intramolecular NHTK reaction in natural product synthesis.1 Introduction2 Total Synthesis of (+)-Pestalotiopsin A3 Total Synthesis of (+)-Cytosporolide A4 Total Synthesis of (+)-Vibsanin A5 Total Syntheses of (+)-Aquatolide and Related Humulanolides6 Conclusion

A Short Synthesis of (+)-Brefeldin C via Enantioselective Radical Hydroalkynylation

2019 ◽  
Author(s):  
Lars Gnägi ◽  
Severin Vital Martz ◽  
Daniel Meyer ◽  
Robin Marc Schärer ◽  
Philippe Renaud
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Oxidation State ◽  
Single Step ◽  
Radical Process ◽  
Target Molecule ◽  
Short Synthesis ◽  
The One

<div><div><div><div><p>A very concise total synthesis of (+)-brefeldin C starting from 2-furanylcyclopentene is described. This approach is based on an unprecedented enantioselective radical hydroalkynylation process to introduce the two cyclopentane stereocenters in a single step. The use of a furan substituent allows to achieve a high trans diastereoselectivity during the radical process and it contains the four carbon atoms C1–C4 of the natural product in an oxidation state closely related to the one of the target molecule. The eight-step synthesis require six product purifications and it provides (+)-brefeldin C in 18% overall yield.</p></div></div></div></div>

Nonbiomimetic total synthesis of indole alkaloids using alkyne-based strategies

2021 ◽  
Vol 19 (16) ◽  
pp. 3551-3568
Author(s):  
Hiroaki Ohno ◽  
Shinsuke Inuki
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Indole Alkaloids ◽  
Natural Product Synthesis ◽  
Total Syntheses

Significance of nonbiomimetic natural product synthesis and nonbiomimetic total syntheses of indole alkaloids based on the construction of core structures using alkyne reactions are summarized in this review.

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