scholarly journals Palladium(ii)-catalysed total synthesis of naturally occurring pyrano[3,2-a]carbazole and pyrano[2,3-b]carbazole alkaloids

2014 ◽  
Vol 12 (23) ◽  
pp. 3866-3876 ◽  
Author(s):  
Ronny Hesse ◽  
Anne Jäger ◽  
Arndt W. Schmidt ◽  
Hans-Joachim Knölker
Keyword(s):  
Total Synthesis ◽  
Naturally Occurring ◽  
Carbazole Alkaloids

Seven naturally occurring pyranocarbazole alkaloids (pyrayafoline A–E,O-methylmurrayamine A andO-methylmahanine) have been synthesised using a palladium(ii)-catalysed cyclisation of a diarylamine to an orthogonally diprotected 2,7-dihydroxycarbazole as key step.

scholarly journals Semi-Synthesis of Small Molecules of Aminocarbazoles: Tumor Growth Inhibition and Potential Impact on p53

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1637
Author(s):  
Solida Long ◽  
Joana B. Loureiro ◽  
Carla Carvalho ◽  
Luís Gales ◽  
Lucília Saraiva ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Small Molecules ◽  
Tumor Cells ◽  
Mutant P53 ◽  
Wild Type ◽  
Naturally Occurring ◽  
Growth Inhibitory ◽  
Growth Inhibitory Activity ◽  
Amino Derivatives ◽  
Carbazole Alkaloids

The tumor suppressor p53 is inactivated by mutation in approximately 50% of human cancers. Small molecules that bind and stabilize those mutants may represent effective anticancer drugs. Herein, we report the tumor cell growth inhibitory activity of carbazole alkaloids and amino derivatives, as well as their potential activation of p53. Twelve aminocarbazole alkaloids were semi-synthesized from heptaphylline (1), 7-methoxy heptaphylline (2), and 7-methoxymukonal (3), isolated from Clausena harmandiana, using a reductive amination protocol. Naturally-occurring carbazoles 1–3 and their amino derivatives were evaluated for their potential effect on wild-type and mutant p53 activity using a yeast screening assay and on human tumor cell lines. Naturally-occurring carbazoles 1–3 showed the most potent growth inhibitory effects on wild-type p53-expressing cells, being heptaphylline (1) the most promising in all the investigated cell lines. However, compound 1 also showed growth inhibition against non-tumor cells. Conversely, semi-synthetic aminocarbazole 1d showed an interesting growth inhibitory activity in tumor cells expressing both wild-type and mutant p53, exhibiting low growth inhibition on non-tumor cells. The yeast assay showed a potential reactivation of mutant p53 by heptaphylline derivatives, including compound 1d. The results obtained indicate that carbazole alkaloids may represent a promising starting point to search for new mutp53-reactivating agents with promising applications in cancer therapy.

Divergent Total Synthesis of (±)‐Mahanine and Other Carbazole Alkaloids

2021 ◽  
Author(s):  
Ranjan Jana ◽  
Arghya Polley ◽  
Kasarla Varalaxmi ◽  
Arijit Nandi
Keyword(s):  
Total Synthesis ◽  
Carbazole Alkaloids

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.

ChemInform Abstract: Total Synthesis and Determination of the Absolute Configuration of FD-838, a Naturally Occurring Azaspirobicyclic Product.

ChemInform ◽  
2009 ◽  
Vol 40 (47) ◽  
Author(s):  
Yujiro Hayashi ◽  
Kuppusamy Sankar ◽  
Hayato Ishikawa ◽  
Yuriko Nozawa ◽  
Kazutoshi Mizoue ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Absolute Configuration ◽  
Naturally Occurring ◽  
The Absolute

First total synthesis of a naturally occurring nucleoside disulfide: 9-(5′-Deoxy-5′-thio-β-d-xylofuranosyl)adenine disulfide

2012 ◽  
Vol 23 (9) ◽  
pp. 996-998 ◽  
Author(s):  
Hai Xin Ding ◽  
Ling Cui Da ◽  
Ru Chun Yang ◽  
Ban Peng Cao ◽  
Qi Sun ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Naturally Occurring
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