scholarly journals The Rearrangement of Alkylallenes to 1,3-Dienes

Reactions ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 70-86
Author(s):  
Yassir Al-Jawaheri ◽  
Marc Colin Kimber
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Organic Synthesis ◽  
Building Blocks ◽  
Drug Candidate ◽  
Synthetic Route ◽  
Skeletal Rearrangement ◽  
Synthetic Transformations

1,3-Dienes are vital building blocks in organic synthesis. They underpin many fundamental synthetic transformations and are present in numerous natural products and drug candidate molecules. The rearrangement of an alkylallene to a 1,3-diene is an atom efficient, redox neutral, transformation that provides a straightforward synthetic route to functionalized 1,3-dienes. Herein, we provide an account of this transformation using allenes that are not predisposed by the presence of heteroatoms or electron-withdrawing groups directly attached to the allene. Early reports of this skeletal rearrangement are acid-mediated approaches, with limited substrate scope, but they provide valuable mechanistic insights. More recent transition metal-mediated approaches that exhibit improved substrate scope are described, together with isolated examples that have utilized this rearrangement.

Transition-metal-catalyzed ortho-selective C−H functionalization reactions of free phenols

2021 ◽  
Author(s):  
So Won Youn ◽  
Cheon-Gyu Cho
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Functional Materials ◽  
Building Blocks ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Synthetic Transformations

Phenols are important readily available chemical feedstocks and versatile synthetic building blocks for diverse synthetic transformations. Their motifs are prevalent in a diverse array of natural products, pharmaceuticals, functional materials,...

Recent Advance on Benzofuranones: Synthesis and Transformation via C-H Functionalization

Synthesis ◽  
2021 ◽  
Author(s):  
Zhi Tang ◽  
Zhou Tong ◽  
Shuang-Feng Yin ◽  
Nobuaki Kambe ◽  
Renhua Qiu
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Organic Synthesis ◽  
Building Blocks ◽  
Efficient Synthesis ◽  
Bond Functionalization ◽  
Pka Value ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Benzofuranone is a sort of important skeleton in many fields, such as natural products, pharmaceuticals, building blocks, antioxidants and dyes. Their efficient synthesis and transformations have attracted great attentions in organic synthesis. They can be synthesized by Friedel−Crafts reaction, intramolecular dehydration ring-closing reaction and transition-metal-catalyzed reaction, etc. And their direct utilization to prepare other functional molecules enhances their further application. Due to their low pKa value and easy enolization ability, the transformation of benzofuranones via C(3)-H bond functionalization is a hot issue in the last ten years. Herein, we highlight the advances on the synthesis of benzofuranones and its transformation via C-H functionalization. Some of other transformations related to benzofuranones are also referred in this review.

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.

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

scholarly journals N-Propargylic β-enaminocarbonyls: powerful and versatile building blocks in organic synthesis

RSC Advances ◽  
2017 ◽  
Vol 7 (22) ◽  
pp. 13198-13211 ◽  
Author(s):  
Sattar Arshadi ◽  
Esmail Vessally ◽  
Ladan Edjlali ◽  
Ebrahim Ghorbani-Kalhor ◽  
Rahim Hosseinzadeh-Khanmiri
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Heterocyclic Compounds ◽  
Building Blocks

Nitrogen-containing heterocyclic compounds are not only prevalent in an extensive number of natural products and synthetic pharmaceuticals but are also used as building blocks in organic synthesis.

scholarly journals Arenophile-Mediated Photochemical Dearomatization of Nonactivated Arenes

2020 ◽  
Vol 74 (7) ◽  
pp. 577-583 ◽  
Author(s):  
Mikiko Okumura ◽  
David Sarlah
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Visible Light ◽  
Bioactive Compounds ◽  
Aromatic Compounds ◽  
Ring Opening ◽  
Organic Molecules ◽  
Building Blocks ◽  
Metal Catalyzed

Aromatic compounds are one of the most abundant classes of organic molecules and find utility as precursors for alicyclic hydrocarbon building blocks. While many established dearomatization reactions are exceptionally powerful, dearomatization with concurrent introduction of functionality, i.e. dearomative functionalization, is still a largely underdeveloped field. This review aims to provide an overview of our recent efforts and progress in the development of dearomative functionalization of simple and nonactivated arenes using arenophile-arene cycloaddition platform. These cycloadducts, formed via a visible-light-mediated [4+2]-photocycloaddition, can be elaborated in situ through olefin chemistry or transition-metal-catalyzed ring-opening with carbon-, nitrogen-, and oxygen-based nucleophiles, providing access to diverse structures with functional and stereochemical complexity. Moreover, the dearomatized products are amenable to further elaborations, which effectively install other functionalities onto the resulting alicyclic carbocycles. The utility of the arenophile-mediated dearomatization methods are also highlighted by the facile syntheses of natural products and bioactive compounds through novel disconnections.

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

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 Modern Synthetic Strategies with Organoselenium Reagents: A Focus on Vinyl Selenones

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3148
Author(s):  
Martina Palomba ◽  
Italo Franco Coelho Dias ◽  
Ornelio Rosati ◽  
Francesca Marini
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Multiple Bond ◽  
Building Blocks ◽  
One Pot ◽  
Bond Forming ◽  
One Pot Synthesis ◽  
Bond Forming Reactions ◽  
Synthetic Transformations

In recent years, vinyl selenones were rediscovered as useful building blocks for new synthetic transformations. This review will highlight these advances in the field of multiple-bond-forming reactions, one-pot synthesis of carbo- and heterocycles, enantioselective construction of densely functionalized molecules, and total synthesis of natural products.

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