scholarly journals Application of asymmetric Sharpless aminohydroxylation in total synthesis of natural products and some synthetic complex bio-active molecules

RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6634-6659 ◽  
Author(s):  
Majid M. Heravi ◽  
Tahmineh Baie Lashaki ◽  
Bahareh Fattahi ◽  
Vahideh Zadsirjan
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Biological Activities ◽  
Amino Alcohols ◽  
Complex Molecules

This work shows applications of Asymmetric Sharpless Aminohydroxylation (ASAH) in the stereoselective synthesis of vicinal amino alcohols as important intermediates in the total synthesis of complex molecules and natural products with significant biological activities.

scholarly journals Oxazolidinones as Chiral Auxiliaries in the Asymmetric 1,4-Conjugate Addition Reaction Applied to the Total Synthesis of Natural Products: A Supplemental Mini-Review

2018 ◽  
Vol 15 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Vahideh Zadsirjan ◽  
Majid M. Heravi
Keyword(s):  
Total Synthesis ◽  
Biological Activities ◽  
Conjugate Addition ◽  
Chiral Auxiliary ◽  
Addition Reactions ◽  
Chiral Auxiliaries ◽  
Complex Molecules ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Wide Range

Background: The most frequently used chiral auxiliaries, oxazolidinones (Evans' oxazolidinones) have been employed in 1,4-congugate addition reactions to α,β-unsaturated carbonyl compounds. Supplementary to our previous reports in this mini-review, we attempted to underscore the applications of this strategy in a step (steps) in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Objective: In this mini-review, we try to underscore the applications of oxazolidinones (Evans’ oxazolidinones) in 1,4-congugate addition reactions to α,β-unsaturated carbonyl in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Conclusion: In spite of well-known superiority of asymmetric catalyzed reactions, the use of auxiliarycontrolled reactions are still considered as commanding, vital and sometimes as only tools in the generation of stereogenic centers during the construction of complex molecules and total synthesis of naturally occurring compounds. The commercial availability, or readily accessibility of a wide variety of chiral amino alcohols as starting materials to synthesize a wide range of oxazolidinones is the merits of them. In addition, the ease of removal and subjection to various and diverse stereoselective reactions make oxazolidinones as the ideal and superior chiral auxiliaries. In this regard, they were successfully used in asymmetric 1,4-conjugate addition reactions with high stereoselectivities. The high degree of asymmetric induction can be attributed to the rigid chelation of N-acyloxazolidinones with metal ions, as well as the covering of one face of the system by the bulkiness of 4-substituent. In summary, in this report, the importance of the applications of chiral oxazolidinones as suitable chiral auxiliaries in the stereoselective, 1,4-conjugate addition reactions in asymmetric synthesis and in particular, the total synthesis of naturally occurring compounds and some complex molecules were underscored. Noticeably, in these total syntheses, this chiral auxiliary is controlling the stereochemistry of a newly created stereogenic center as well as preserving the configuration of other chiral centers, which already have been presented in the precursor. General methods have been established for the attachment of the chiral auxiliary as a moiety to the substrate molecule in high to excellent yields. At the end of these reactions, this auxiliary can be easily removed leaving various desired reactive motifs for the next step in multi-step synthesis.

Recent results toward the stereoselective synthesis of biologically active natural products

2007 ◽  
Vol 79 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Luiz C. Dias ◽  
Luciana G. de Oliveira ◽  
Paulo R. R. Meira
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Cell Cultures ◽  
Stereoselective Synthesis ◽  
Animal Cell ◽  
Biologically Active ◽  
Asymmetric Total Synthesis ◽  
Callystatin A ◽  
Animal Cell Cultures ◽  
Active Natural

This paper describes the convergent and stereocontrolled asymmetric total synthesis of (+)-crocacins C and D, potent inhibitors of animal cell cultures and several yeasts and fungi, and (-)-callystatin A, a potent antitumor polyketide.

scholarly journals Synthetic Approaches to Tetracyclic Pyrrole Imidazole Marine Alkaloids

2013 ◽  
Vol 8 (7) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Takuya Imaoka ◽  
Makoto Iwata ◽  
Takafumi Akimoto ◽  
Kazuo Nagasawa
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Anticancer Activity ◽  
Biological Activities ◽  
Structural Complexity ◽  
Marine Alkaloids ◽  
Ring Systems ◽  
Agonistic Activity ◽  
Synthetic Approaches

Oroidin derived pyrrole imidazole marine alkaloids (PIAs) are attractive targets for synthetic organic chemists because of their structural complexity and diversity as well as their interesting biological activities. A number of efforts have been carried out to develop strategies for the synthesis of these natural products. Members of PIAs ( eg., 2-7) which contain tetracyclic ring systems possessing characteristic cyclic guanidine or urea moieties show significant biological activities including anticancer activity and agonistic activity against the adrenoceptor. In this review investigations of the total synthesis of the representative tetracyclic PIAs dibromophakellin (2) and dibromophakellstatin (3) are described.

Biomimetic approach toward the stereoselective synthesis of acetogenins

2003 ◽  
Vol 75 (2-3) ◽  
pp. 259-264 ◽  
Author(s):  
R. V. A. Orru ◽  
Bas Groenendaal ◽  
J. van Heyst ◽  
Mark Hunting ◽  
C. Wesseling ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Broad Spectrum ◽  
Stereoselective Synthesis ◽  
Biological Activities ◽  
Building Blocks ◽  
Hydrocarbon Chain ◽  
Tropical Trees ◽  
Asymmetric Total Synthesis ◽  
Biomimetic Approach

Acetogenins isolated from the Annonaceae family of tropical trees have drawn considerable attention owing to their broad spectrum of biological activities. They are structurally characterized by the presence of one to three tetrahydrofuran rings in the center of a long (partly hydroxylated) hydrocarbon chain that ends in a (functionalized) butenolide moiety. Here we describe some of our results toward the first asymmetric total synthesis of cis-gigantrionenin, a principal acetogenin. In this approach, an enzyme-catalyzed epoxide hydrolysis and an enzyme-triggered double cyclization are crucial and give stereoselective access to essential chiral building blocks.

Total synthesis of bryostatin 3

Science ◽  
2020 ◽  
Vol 368 (6494) ◽  
pp. 1007-1011 ◽  
Author(s):  
Barry M. Trost ◽  
Youliang Wang ◽  
Andreas K. Buckl ◽  
Zhongxing Huang ◽  
Minh H. Nguyen ◽  
...  
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Marine Natural Products ◽  
Biological Activities ◽  
Step Count ◽  
Total Syntheses ◽  
Linear Sequence ◽  
Wide Range

Bryostatins are a family of 21 complex marine natural products with a wide range of potent biological activities. Among all the 21 bryostatins, bryostatin 3 is structurally the most complex. Whereas nine total syntheses of bryostatins have been achieved to date, bryostatin 3 has only been targeted once and required the highest number of steps to synthesize (43 steps in the longest linear sequence and 88 total steps). Here, we report a concise total synthesis of bryostatin 3 using 22 steps in the longest linear sequence and 31 total steps through a highly convergent synthetic plan by the use of highly atom-economical and chemoselective transformations in which alkynes played a major role in reducing step count.

scholarly journals Synthesis and Structural Confirmation of the Thiazole Alkaloids Derived from Peganum harmala L.

2021 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Myeonghyeon Sim ◽  
Sujin Lee ◽  
Youngtaek Han
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Spectral Data ◽  
Spectroscopic Analysis ◽  
Biological Activities ◽  
Peganum Harmala

Peganumal A and B are thiazole alkaloids isolated from the seeds of Peganum harmala L. Thiazole moieties are rarely found in natural products, but diverse compounds possessing thiazole moieties have attracted attention owing to their broad range of biological activities. Peganumals are the first natural thiazole compounds isolated from the genus Peganum. It was difficult to define the exact structure of peganumal A via spectroscopic analysis. In this paper, we report the first total synthesis of peganumal A and B. The 5-benzylthiazole skeleton possessing methyl or hydrogen at the 2-position of the peganumals was efficiently constructed via the Hantzsch thiazole synthesis of the α-bromoaldehyde intermediate. Moreover, the spectral data of the synthetic 2H–thiazole compound were identical to those previously reported for peganumal A. The synthesis allowed the confirmation of the structure of peganumal A.

The Art of Total Synthesis of Bioactive Natural Products via Microwaves

2021 ◽  
Vol 25 ◽  
Author(s):  
Sasadhar Majhi
Keyword(s):  
Natural Products ◽  
Microwave Irradiation ◽  
Total Synthesis ◽  
Biological Activities ◽  
Complex Structure ◽  
Reaction Times ◽  
Side Reactions ◽  
Bioactive Natural Products ◽  
Classical Methodology ◽  
Green Technique

: Natural products are the most effective source of potential drug leads. The total synthesis of bioactive natural products plays a crucial role to confirm the hypothetical complex structure of natural products in the laboratory. The total synthesis of rare bioactive natural products is one of the great challenges for the organic synthetic community due to their complex structures, biochemical specificity, and stubborn stereochemistry. Subsequently, the total synthesis is a long process in several cases and it requires a substantial amount of time. Microwave irradiation has emerged as a greener tool in organic methodologies to reduce reaction times from days and hours to minutes and seconds. Moreover, this non-classical methodology increases product yields and purities, improves reproducibility, modifications of selectivity, simplification of work-up methods, and reduces unwanted side reactions. Such beneficial qualities have stimulated this review to cover the application of microwave irradiation in the field of the total synthesis of bioactive natural products for the first time during the last decade. An overview of the use of microwave irradiation, natural sources, structures, and biological activities of secondary metabolites is presented elegantly, focusing on the involvement of at least one or more steps by microwave irradiation as a green technique.

C–O Containing Natural Products

2015 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Natural Product ◽  
Biological Activities ◽  
Max Planck ◽  
Penicillium Species ◽  
Antimitotic Agent ◽  
Berkelic Acid ◽  
Metal Catalyzed ◽  
The University

It is thought that the pseudopterane class of diterpenoid natural products, of which 11-gorgiacerol is a member, arises biosynthetically by a photo-ring contraction of the related furanocembranes. Johann Mulzer at the University of Vienna has applied (Org. Lett. 2012, 14, 2834) this logic to realize the total synthesis of 11-gorgiacerol. Ringclosing metathesis of the butenolide 1 using the Grubbs second generation catalyst produced the tricycle 2. When irradiated, 2 undergoes a 1,3-rearrangement to furnish the natural product in good yield. Whether this rearrangement is concerted, or occurs stepwise via a diradical intermediate, is not known. Although ring-closing metathesis has become a reliable method for macrocycle construction, its use here to set what then becomes an extracyclic olefin is notable. Berkelic acid is produced by an extremophile bacterium penicillium species that lives in the toxic waters of an abandoned copper mine, and this natural product has been found to possess some very intriguing biological activities. Not surprisingly, berkelic acid has attracted significant attention from synthetic chemists, including Francisco J. Fañanás of Universidad de Oviedo in Spain, who has developed (Angew. Chem. Int. Ed. 2012, 51, 4930) a scalable, protecting-group free total synthesis. The key step in this route is the remarkable silver(I)-catalyzed coupling of alkyne 3 and aldehyde 4 to produce, after hydrogenation, the structural core 5 of (–)-berkelic acid on a gram scale. Some tools from the field of organocatalysis have been brought to bear (Angew. Chem. Int. Ed. 2012, 51, 5735) on a new total synthesis of the macrolide (+)-dactylolide by Hyoungsu Kim of Ajou University in Korea and Jiyong Hong of Duke University. The bridging tetrahydropyranyl ring is fashioned by way of an intramolecular 1,6-oxa conjugate addition of dienal 6 to produce 8 under catalysis by the secondary amine 7. Following some synthetic manipulations, the macrocyclic ring 12 is subsequently forged by an NHC-catalyzed oxidative macrolactonization using the carbene catalyst 10 and diphenoquinone 11 as the oxidant. A new approach to the nanomolar antimitotic agent spirastrellolide F methyl ester has been reported (Angew. Chem. Int. Ed. 2012, 51, 8739) by Alois Fürstner of the Max-Planck-Institut, Mülheim. Two elegant metal-catalyzed processes form the key basis of this strategy.

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