Catalytic Asymmetric Osmium-Free Dihydroxylation of Alkenes

Synthesis ◽  
2020 ◽  
Author(s):  
Chuan Wang ◽  
Shixia Su
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Phase Transfer ◽  
Building Blocks ◽  
Short Review ◽  
Optically Active ◽  
Asymmetric Dihydroxylation ◽  
A Subunit ◽  
Vicinal Diols ◽  
Catalytic Asymmetric

AbstractAsymmetric dihydroxylation of alkenes is one of the cornerstone reactions in organic synthesis, providing a direct entry to optically active vicinal diols, which are not only a subunit in natural products but also versatile building blocks. In recent years, considerable progress in catalytic asymmetric osmium-free dihydroxylation has been achieved. This short review presents a concise summary of the reported methods of catalytic asymmetric osmium-free dihydroxylation.1 Introduction2 Iron-Catalyzed Asymmetric syn-Dihydroxylation of Alkenes3 Manganese-Catalyzed Asymmetric syn-Dihydroxylation of Alkenes4 Palladium/Gold Bimetallic Nanocluster-Catalyzed Asymmetric syn-Dihydroxylation of Alkenes5 Enzyme-Catalyzed Asymmetric anti-Dihydroxylation of Alkenes6 Amine-Catalyzed Asymmetric Formal anti-Dihydroxylation of Enals7 Diselenide-Catalyzed anti-Dihydroxylation of Alkenes8 Molybdenum-Catalyzed Asymmetric anti-Dihydroxylation of Allylic­ Alcohols9 Phase-Transfer-Catalyzed Asymmetric Dihydroxylation of α-Aryl Acrylates10 Conclusion

scholarly journals Catalytic Asymmetric Intramolecular Darzens Reaction of 2-Halomalonate Derivatives

2019 ◽  
Vol 14 (10) ◽  
pp. 1934578X1988440
Author(s):  
Kenichi Kobayashi ◽  
Kosaku Tanaka ◽  
Momoko Suzuki ◽  
Hiroshi Kogen
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Phase Transfer ◽  
Building Blocks ◽  
Natural Product Synthesis ◽  
Darzens Reaction ◽  
Phase Transfer Catalysts ◽  
Catalytic Asymmetric

A catalytic asymmetric intramolecular Darzens reaction of 2-halomalonate derivatives was developed for the enantioselective preparation of chiral building blocks for epoxide-containing natural products. Among the screened catalysts, some phase-transfer catalysts gave the desired epoxide in moderate enantioselectivity, albeit in low yield. The epoxide product would be useful as versatile chiral building blocks for natural product synthesis.

Isoxazol-5-ones as Strategic Building Blocks in Organic Synthesis

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2473-2489 ◽  
Author(s):  
Amanda da Silva ◽  
Alessandra Fernandes ◽  
Samuel Thurow ◽  
Mateus Stivanin ◽  
Igor Jurberg
Keyword(s):  
Natural Products ◽  
Biological Activity ◽  
Organic Synthesis ◽  
Building Block ◽  
Building Blocks ◽  
Short Review ◽  
Preparation Methods ◽  
Drug Candidates ◽  
General Aspects

Isoxazol-5-one rings have been identified as relevant motifs in drug candidates, agrochemicals, and materials. Furthermore, this heterocycle has been also applied as a versatile building block for the preparation of a variety of densely functionalized molecules. This short review will present the most representative applications of isoxazol-5-ones in organic synthesis while discussing their properties and reactivity.1 Introduction1.1 General Aspects1.1.1 Tautomerism1.1.2 Importance: Natural Products Isolation, Biological Activity, and Materials1.1.3 Preparation Methods2 Isoxazol-5-ones in Organic Synthesis2.1 General Reactivity2.2 Specific Examples2.2.1 Alkylation Strategies2.2.2 Alkyne Synthesis2.2.3 Annulation Reactions2.2.4 N–O Bond Insertions2.2.4.1 Preparation of 1,3-Oxazin-6-ones3 Conclusions

Ascending of Cycloaddition Strategy for N-O Heterocycles

Synthesis ◽  
2021 ◽  
Author(s):  
Prasanjit Ghosh ◽  
Swati Lekha Mondal ◽  
Mahiuddin Baidya
Keyword(s):  
Organic Synthesis ◽  
Building Blocks ◽  
Short Review ◽  
Biologically Relevant

The N–O heterocycles are biologically relevant scaffolds and versatile building blocks in contemporary organic synthesis. In this short review, we effort to showcase the involvement and elevation of various cycloaddition strategies towards the production of N–O heterocycles 1,2-oxazines, 1,2-oxazepanes, and 1,2-oxazetidines. A blueprint of advantages and challenges associated with these synthetic endeavors is provided.

scholarly journals Recent Advances in Organocatalyzed Asymmetric Synthesis of Benzopyran and Benzodihydropyran (Chromane) Nuclei

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1510
Author(s):  
Renato Dalpozzo ◽  
Raffaella Mancuso
Keyword(s):  
Natural Products ◽  
Asymmetric Synthesis ◽  
Organic Synthesis ◽  
Building Blocks ◽  
Core Structure ◽  
The Core ◽  
Recent Advances ◽  
Set Up

Benzopyran and benzodihydropyran (chromane) nuclei are the core structure of many natural products, in particular flavonoids. Many compounds possessing this structure are nutraceuticals, pharmaceutical nutrients. Therefore, benzopyran and chromane scaffolds are important building blocks in organic synthesis and many efforts have been made to set up efficient methods for their synthesis. In particular, asymmetric methods are of great importance, being natural products, and generally chiral substances. This review aims to cover literature in the range 2017–first half of 2019.

Use of enzymes as catalysts to promote key transformations in organic synthesis

1989 ◽  
Vol 324 (1224) ◽  
pp. 577-587 ◽  
Keyword(s):  
Organic Synthesis ◽  
Large Scale ◽  
Immobilized Enzymes ◽  
Building Blocks ◽  
Optically Active ◽  
The Past ◽  
Small Proteins ◽  
Areas Of Interest ◽  
Oxidation Of Benzene ◽  
Reduction Of Ketones

The field of biotransformations has developed rapidly over the past eight years. The use of esterases and lipases is now widespread; these enzymes are of particular importance in the production of optically active building blocks for organic synthesis as well as in large-scale processes involving the transesterification of fats. The latter area (i.e. the catalysis of esterification processes) has stimulated research into the properties of immobilized enzymes and the use of enzymes in low-water systems. In related work, enzymes have been used for the preparation of peptides and small proteins. Redox enzymes have been investigated extensively, particularly with regard to the stereocontrolled reduction of ketones to secondary alcohols. The methods for using commercially available enzymes of this type have become increasingly ‘userfriendly’. The controlled oxidation of hydrocarbon units is another area that has deserved increased attention. For example, oxidation of benzene and simple derivatives by Pseudomonas sp. has been researched by a number of U.K. groups. These recent advances in enzyme-catalysed reactions (using both whole-cell systems and partly purified protein) for the transformation of unnatural substrates is discussed and some areas of interest for the future are outlined.

scholarly journals Strategies To Access γ-Hydroxy-γ-butyrolactams

Synthesis ◽  
2018 ◽  
Vol 50 (06) ◽  
pp. 1175-1198 ◽  
Author(s):  
Laurent Commeiras ◽  
Muhammad Idham Darussalam Mardjan ◽  
Jean-Luc Parrain
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Broad Spectrum ◽  
Heterocyclic Compounds ◽  
Biological Activities ◽  
Building Blocks ◽  
Pharmaceutical Molecules

α,β-Unsaturated γ-hydroxy-γ-butyrolactams are of a great interest due to their presence in designed pharmaceutical molecules and numerous natural products displaying a broad spectrum of biological activities. In addition, these five-membered heterocyclic compounds are also relevant and versatile building blocks in organic synthesis. In this context, strategies for the construction of these scaffolds has triggered considerable attention and this review highlights the progress in the formation of α,β-unsaturated γ-hydroxy-γ-butyrolactams (5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones).1 Introduction2 Intramolecular Routes3 Intermolecular Routes4 Oxidation of Heterocyclic Compounds5 Miscellaneous6 Conclusion

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