Enantioselective Syntheses of (-)-Alloyohimbane and (-)-Yohimbane by an Efficient Enzymatic Desymmetrization Process

Arun K. Ghosh; Anindya Sarkar

doi:10.1002/ejoc.201601171

Enantioselective Syntheses of Flavonoid Diels-Alder Natural Products: A Review

Current Organic Synthesis ◽

10.2174/1570179414666170821120234 ◽

2018 ◽

Vol 15 (2) ◽

pp. 221-229 ◽

Cited By ~ 3

Author(s):

Shah Bakhtiar Nasir ◽

Noorsaadah Abd Rahman ◽

Chin Fei Chee

Keyword(s):

Natural Products ◽

Organic Synthesis ◽

Lewis Acid ◽

Alder Reaction ◽

Diels Alder ◽

Enantioselective Synthesis ◽

Chiral Ligand ◽

Asymmetric Syntheses ◽

Diels Alder Reaction ◽

Enantioselective Syntheses

Background: The Diels-Alder reaction has been widely utilised in the syntheses of biologically important natural products over the years and continues to greatly impact modern synthetic methodology. Recent discovery of chiral organocatalysts, auxiliaries and ligands in organic synthesis has paved the way for their application in Diels-Alder chemistry with the goal to improve efficiency as well as stereochemistry. Objective: The review focuses on asymmetric syntheses of flavonoid Diels-Alder natural products that utilize chiral ligand-Lewis acid complexes through various illustrative examples. Conclusion: It is clear from the review that a significant amount of research has been done investigating various types of catalysts and chiral ligand-Lewis acid complexes for the enantioselective synthesis of flavonoid Diels-Alder natural products. The results have demonstrated improved yield and enantioselectivity. Much emphasis has been placed on the synthesis but important mechanistic work aimed at understanding the enantioselectivity has also been discussed.

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Non-Enzymatic Desymmetrization Reactions in Aqueous Media

Symmetry ◽

10.3390/sym13040720 ◽

2021 ◽

Vol 13 (4) ◽

pp. 720

Author(s):

Satomi Niwayama

Keyword(s):

Natural Products ◽

Total Synthesis ◽

Functional Groups ◽

Organic Compounds ◽

Recent Progress ◽

Aqueous Media ◽

Building Blocks ◽

Organic Reactions ◽

Environmentally Benign ◽

Enzymatic Desymmetrization

Symmetric organic compounds are generally obtained inexpensively, and therefore they can be attractive building blocks for the total synthesis of various pharmaceuticals and natural products. The drawback is that discriminating the identical functional groups in the symmetric compounds is difficult. Water is the most environmentally benign and inexpensive solvent. However, successful organic reactions in water are rather limited due to the hydrophobicity of organic compounds in general. Therefore, desymmetrization reactions in aqueous media are expected to offer versatile strategies for the synthesis of a variety of significant organic compounds. This review focuses on the recent progress of desymmetrization reactions of symmetric organic compounds in aqueous media without utilizing enzymes.

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Design and synthesis of herboxidiene derivatives that potently inhibit in vitro splicing

Organic & Biomolecular Chemistry ◽

10.1039/d0ob02532a ◽

2021 ◽

Vol 19 (6) ◽

pp. 1365-1377

Author(s):

Arun K. Ghosh ◽

Srinivasa Rao Allu ◽

Guddeti Chandrashekar Reddy ◽

Adriana Gamboa Lopez ◽

Patricia Mendez ◽

...

Keyword(s):

Biological Evaluation ◽

Design And Synthesis ◽

In Vitro Splicing ◽

Enantioselective Syntheses ◽

Derivatives Of

Enantioselective syntheses of C-6 modified derivatives of herboxidiene and their biological evaluation in splicing inhibitory assay.

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Asymmetric Synthetic Strategies of (R)-(–)-Baclofen: An Antispastic Drug

Synthesis ◽

10.1055/s-0036-1590938 ◽

2017 ◽

Vol 50 (02) ◽

pp. 211-226 ◽

Cited By ~ 17

Author(s):

Perla Ramesh ◽

Devatha Suman ◽

Koti Reddy

Keyword(s):

Asymmetric Reduction ◽

Asymmetric Hydrogenation ◽

Asymmetric Aldol ◽

Asymmetric Michael Addition ◽

Chemical Resolution ◽

Enzymatic Desymmetrization ◽

Catalytic Asymmetric ◽

Aldol Addition ◽

Synthetic Approaches ◽

Catalytic Asymmetric Hydrogenation

Baclofen is an antispastic drug used as a muscle relaxant in the treatment of the paroxysmal pain of trigeminal neuralgia, spasticity of the spinal cord and cerebral origin. Baclofen resides biological activity exclusively in its (R)-(–)-enantiomer. In this review, various asymmetric synthetic strategies for (R)-(–)-baclofen are described.1 Introduction2 Resolution Synthetic Approaches2.1 Chemical Resolution2.2 Biocatalytic Resolution3 Asymmetric Desymmetrization3.1 Catalytic Enantioselective Desymmetrization3.2 Enzymatic Desymmetrization4 Chiral Auxiliary Induced Asymmetric Synthesis4.1 Asymmetric Michael Addition4.2 Asymmetric Aldol Addition4.3 Asymmetric Nucleophilic Substitution5 Asymmetric Reduction5.1 Catalytic Asymmetric Hydrogenation5.2 Bioreduction6 Catalytic Asymmetric Conjugate Addition7 Conclusion

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