Reactions In Natural Product Synthesis Research Articles

An Overview of Julia-lythgoe Olefination.

Julia-Lythgoe olefination (or simply Julia olefination) is an olefination process between phenyl sulfones and aldehydes (or ketones) to give alkenes after alcohol functionalization and reductive elimination using sodium amalgam or SmI2. It is mainly used to synthesize E-alkenes and is a key step in numerous total syntheses of many natural products. This review exclusively deals with the Julia-Lythgoe olefination and concentrates mainly on the applications of this reaction in natural product synthesis covering literature up to 2021.

Chemoenzymatic Synthesis of Cylindrocyclophanes A and F and Merocyclophanes A and D

AbstractIncorporating enzymatic reactions into natural product synthesis can significantly improve synthetic efficiency and selectivity. In contrast to the increasing applications of biocatalytic functional‐group interconversions, the use of enzymatic C−C bond formation reactions in natural product synthesis is underexplored. Herein, we report a concise and efficient approach for the synthesis of [7.7]paracyclophane natural products, a family of polyketides with diverse biological activities. By using enzymatic Friedel–Crafts alkylation, cylindrocyclophanes A and F and merocyclophanes A and D were synthesized in six to eight steps in the longest linear sequence. This study demonstrates the power of combining enzymatic reactions with contemporary synthetic methodologies and provides opportunities for the structure–activity relationship studies of [7.7]paracyclophane natural products.

Chemoenzymatic Synthesis of Cylindrocyclophanes A and F and Merocyclophanes A and D.

Incorporating enzymatic reactions into natural product synthesis can significantly improve synthetic efficiency and selectivity. In contrast to the increasing applications of biocatalytic functional-group interconversions, the use of enzymatic C-C bond formation reactions in natural product synthesis is underexplored. Herein, we report a concise and efficient approach for the synthesis of [7.7]paracyclophane natural products, a family of polyketides with diverse biological activities. By using enzymatic Friedel-Crafts alkylation, cylindrocyclophanes A and F and merocyclophanes A and D were synthesized in six to eight steps in the longest linear sequence. This study demonstrates the power of combining enzymatic reactions with contemporary synthetic methodologies and provides opportunities for the structure-activity relationship studies of [7.7]paracyclophane natural products.

Biomimetic Diels–Alder Reactions in Natural Product Synthesis: A Personal Retrospect

AbstractNature has been recognized for her super capability of constructing complex molecules with remarkable efficiency and elegancy. Among nature’s versatile synthetic toolkits, Diels–Alder reaction is particularly attractive since it allows for rapid generation of molecular complexity from simple precursors. For natural products biosynthetically formed through Diels–Alder reactions, the most straightforward way to access them should build on biomimetic Diels–Alder reactions. However, the implementation of biomimetic Diels–Alder reactions in a laboratory setting may encounter considerable challenges, particularly for those suffering from complicated reactivity and selectivity issues. Indeed, the translation of a biosynthetic hypothesis into a real biomimetic synthesis entails the orchestrated combination of nature’s inspiration and chemist’s rational design. In this Account, we will briefly summarize our recent progress on the application of biomimetic Diels–Alder reactions in natural product synthesis. As shown in the discussed stories, rational manipulation of the structures of biosynthetic precursors plays a crucial role for the successful implementation of biomimetic Diels–Alder reactions.1 Introduction2 Biomimetic Synthesis of Rossinone B3 Biomimetic Synthesis of Homodimericin A4 Biomimetic Synthesis of Polycyclic and Dimeric Xanthanolides5 Biomimetic Synthesis of Periconiasins and Pericoannosins6 Biomimetic Synthesis of Merocyctochalasans7 Conclusion and Outlook

Application of the Radical Polyene Cyclization Reaction in Natural Product Synthesis

Application of the Radical Polyene Cyclization Reaction in Natural Product Synthesis

Recent Advance of Domino Michael Reaction in Natural Product Synthesis

Recent advances in the total syntheses of cyclic natural products and related compounds from 2005 to 2021, which employ domino Michael reactions as key steps, have been reviewed, focusing mainly on the domino Michael reactions catalyzed by organocatalysts.

The Synthesis of Conjugated Bis-Aryl Vinyl Substrates and Their Photoelectrocyclization Reactions towards Phenanthrene Derivatives.

The photoelectrocyclization of conjugated vinyl biaryls has proven to be a valuable and efficient strategy for generating phenanthrene derivatives. Contained in this review is an overview of the mechanism for the transformation and a discussion of the reaction scope with a focus on the electrocyclization itself, rearomatization, and the application of the reaction in natural product synthesis.

Metal-hydride hydrogen atom transfer (MHAT) reactions in natural product synthesis

Functionalization of olefins has been an important transformation in synthetic chemistry. This review will focus on the natural product synthesis employing the MHAT reaction as the key strategy.

Recent applications of asymmetric organocatalytic annulation reactions in natural product synthesis.

The past two decades have witnessed remarkable growth of asymmetric organocatalysis, which is now a firmly established synthetic tool, serving as a powerful platform for the production of chiral molecules. Ring structures are ubiquitous in organic compounds, and, in the context of natural product synthesis, strategic construction of ring motifs is often crucial, fundamentally impacting the eventual fate of the whole synthetic plan. In this review, we provide a comprehensive and updated summary of asymmetric organocatalytic annulation reactions; in particular, the application of these annulation strategies in natural product synthesis will be highlighted.

The Dötz Benzannulation Reaction: A Booming Methodology for Natural Product Synthesis

AbstractSince its finding in 1975, the Dötz benzannulation reaction has attracted a great attention of the scientific community as it permits the regio‐controlled construction of functionalised aromatic frameworks from acyclic precursors. In recent years, this beautifully simple yet much powerful technique for the formation of C−C bonds has opened‐up new possibilities in modern synthetic organic chemistry. In this Review, we report the developments in natural products synthesis by employing the Dötz benzannulation as a key transformation. Although, a flow of publications have witnessed a constant progress in this wonderful area of research, but to our best knowledge this is the first review which purely focuses on the applications of the Dötz benzannulation reaction in natural product synthesis. We are assured that this review will act as a promoter in amplifying the applications of the Dötz benzannulation in the domain of synthetic organic chemistry.

Total Synthesis of Natural Products Using Intramolecular Nozaki–Hiyama–Takai–Kishi Reactions

In this Account, we describe our studies on the total synthesis of several natural products using intramolecular Nozaki–Hiyama–Takai–Kishi (NHTK) reactions. In each synthesis, an NHTK reaction is used to efficiently construct a medium-sized ring. These examples demonstrate the utility of the intramolecular NHTK reaction in natural product synthesis.1 Introduction2 Total Synthesis of (+)-Pestalotiopsin A3 Total Synthesis of (+)-Cytosporolide A4 Total Synthesis of (+)-Vibsanin A5 Total Syntheses of (+)-Aquatolide and Related Humulanolides6 Conclusion

Ir-Catalyzed reactions in natural product synthesis

This review highlights the recent applications of Ir-catalyzed reactions in the total synthesis of natural products.

Metal-mediated C–O bond forming reactions in natural product synthesis

Metal catalyzed reactions for the formation of C(sp2)–O bonds have had a dramatic impact in natural product synthesis. They have enabled the emergence of new bond disconnections, which notably resulted in remarkably efficient and short synthetic pathways. The use of these reactions for the formation of C–O bonds in natural product synthesis is overviewed in this critical review.

Metal-Catalyzed Asymmetric Michael Addition in Natural Product Synthesis.

Asymmetric catalysis for chiral compound synthesis is a rapidly growing field in modern organic chemistry. Asymmetric catalytic processes have been indispensable for the synthesis of enantioselective materials to meet demands from various fields. Michael addition has been used extensively for the construction of C-C bonds under mild conditions. With the discovery and development of organo- and metal-catalyzed asymmetric Michael additions, the synthesis of enantioselective and/or diastereoselective Michael adducts has become possible and increasingly prevalent in the literature. In particular, metal-catalyzed asymmetric Michael addition has been employed as a key reaction in natural product synthesis for the construction of contiguous quaternary stereogenic center(s), which is still a difficult task in organic synthesis. Previously reported applications of metal-catalyzed asymmetric Michael additions in natural product synthesis are presented here and discussed in depth.

Synthesis of Neurotrophic Seco-prezizaane Sesquiterpenes (1R,10S)-2-Oxo-3,4-dehydroneomajucin, (2S)-Hydroxy-3,4-dehydroneomajucin, and (-)-Jiadifenin.

An asymmetric approach to the synthesis of neurotrophic seco-prezizaane sesquiterpenes is described that is based on the strategic application of a hydroxyl-directed metallacycle-mediated [2 + 2 + 2] annulation and an intramolecular radical cyclization cascade. Targets prepared are among the most potent members of the natural product class and include (1R,10S)-2-oxo-3,4-dehydroneomajucin, (2S)-hydroxy-3,4-dehydroneomajucin, and (-)-jiadifenin. In addition to representing the first application of the alkoxide-directed metallacycle-mediated hydrindane-forming annulation reaction in natural product synthesis and the first total synthesis of (2S)-hydroxy-3,4-dehydroneomajucin, these pursuits have resulted in the elucidation of a complex radical cascade process for installation of the C5 quaternary center common to the natural product class.

ChemInform Abstract: Impact of Copper‐catalyzed Cross‐coupling Reactions in Natural Product Synthesis: The Emergence of New Retrosynthetic Paradigms

AbstractReview: 219 refs.

Roger F. C. Brown Memorial Issue

Formal synthesis of kingianin A based upon a novel electrochemically-induced radical cation Diels-Alder reaction.

The application of electrochemical reactions in natural product synthesis has burgeoned in recent years. We herein report a formal synthesis of the complex and dimeric natural product kingianin A, which employs an electrochemically-mediated radical cation Diels-Alder cycloaddition as the key step.

ChemInform Abstract: Palladium‐Catalyzed Chemoselective Catellani ortho‐Arylation Reactions and Their Applications in Natural Products Synthesis

AbstractReview: 58 refs.

Palladium-Catalyzed Chemoselective Catellani ortho-Arylation Reactions and Their Applications in Natural Products Synthesis

This review gave a brief account for the palladium-catalyzed chemoselective Catellani ortho-arylation reactions. Two possible methods were discussed which were usually used to control the chemoselectivities of these ortho-arylation reactions. Additionally, examples of the Catellani reaction in natural product synthesis are also reviewed.