A Decade with Dötz Benzannulation in the Synthesis of Natural Products

Synlett ◽  
2020 ◽  
Vol 31 (05) ◽  
pp. 403-420 ◽  
Author(s):  
Rodney A. Fernandes ◽  
Anupama Kumari ◽  
Ramdas S. Pathare

The Dötz benzannulation is a named reaction that utilizes Fischer chromium carbenes in a formal [3+2+1] cycloaddition with an alkyne and CO to produce the corresponding benzannulated product. Since its development in the 1970s, this reaction has been extensively used in the synthesis of natural products and various molecular architectures. Although the reaction sometimes suffers from the formation of other competing side products, the rapid construction of naphthol structures with a 1,4-dihydroxy unit makes it the most appropriate reaction for the synthesis of p-naphthoquinones. This review focuses on our group’s efforts over the past decade on the extensive use of this annulation reaction along with the contributions of others on the synthesis of different natural products.1 Introduction2 General Description and Mechanism of the Dötz Benzannulation Reaction3 Applications of the Dötz Benzannulation in Natural Product Synthesis over the Last Decade4 Conclusion

Synthesis ◽  
2021 ◽  
Author(s):  
Weilong Liu ◽  
Nicolas Winssinger

The α-exo-methylene-γ-butyrolactone moiety is present in a vast array of structurally diverse natural products and is often central to their biological activity. In this review, we summarize new approaches to α-exo-methylene-γ-butyrolactones developed over the past decade as well as their applications in total synthesis.


2021 ◽  
Author(s):  
Nengzhong Wang ◽  
Zugen Wu ◽  
Junjie Wang ◽  
Nisar Ullah ◽  
Yixin Lu

A comprehensive and updated summary of asymmetric organocatalytic annulation reactions is presented; in particular, the applications of these annulation strategies to natural products synthesis are highlighted.


Synthesis ◽  
2021 ◽  
Author(s):  
Dávid Roman ◽  
Maria Sauer ◽  
Christine Beemelmanns

Here, we have summarized more than 30 representative natural product syntheses published in 2015 to 2020 that employ one or more Horner-Wadsworth-Emmons (HWE) reactions. We comprehensively describe the applied phosphonate reagents, HWE reaction conditions and key steps of the total synthetic approaches. Our comprehensive review will support future synthetic approaches and serve as guideline to find the best HWE conditions for the most complicated natural products known


2022 ◽  
Author(s):  
K. Lam ◽  
M. C. Leech ◽  
A. J. J. Lennox

The multistep synthesis of natural products has historically served as a useful and informative platform for showcasing the best, state-of-the-art synthetic methodologies and technologies. Over the last several decades, electrochemistry has proved itself to be a useful tool for conducting redox reactions. This is primarily due to its unique ability to selectively apply any oxidizing or reducing potential to a sufficiently conductive reaction solution. Electrochemical redox reactions are readily scaled and can be more sustainable than competing strategies based on conventional redox reagents. In this chapter, we summarize the examples where electrochemistry has been used in the synthesis of natural products. The chapter is organized by the reaction type of the electrochemical step and covers both oxidative and reductive reaction modes.


2019 ◽  
Vol 14 (10) ◽  
pp. 1934578X1988440
Author(s):  
Kenichi Kobayashi ◽  
Kosaku Tanaka ◽  
Momoko Suzuki ◽  
Hiroshi Kogen

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.


2011 ◽  
Vol 7 ◽  
pp. 1475-1485 ◽  
Author(s):  
Charles Dylan Turner ◽  
Marco A Ciufolini

This is a review of our efforts toward the synthesis of a group of natural products that display noteworthy biological activity: Fredericamycin A, nothapodytine B, and topopyrones B and D. In each case, directed aromatic functionalization methodology greatly facilitated the assembly of the key molecular subunits.


Synthesis ◽  
2020 ◽  
Vol 52 (14) ◽  
pp. 1991-2007 ◽  
Author(s):  
Alison J. Frontier ◽  
Shukree Abdul-Rashed ◽  
Connor Holt

This review focuses on alkynyl Prins and alkynyl aza-Prins cyclization­ processes, which involve intramolecular coupling of an alkyne with either an oxocarbenium or iminium electrophile. The oxocarbenium or iminium species can be generated through condensation- or elimination-type processes, to achieve an overall bimolecular annulation that enables the synthesis of both oxygen- and nitrogen-containing­ saturated heterocycles with different ring sizes and substitution patterns. Also discussed are cascade processes in which alkynyl Prins heterocyclic adducts react to trigger subsequent pericyclic reactions, including [4+2] cycloadditions and Nazarov electrocyclizations, to rapidly construct complex small molecules. Finally, examples of the use of alkynyl Prins and alkynyl aza-Prins reactions in the synthesis of natural products are described. The review covers the literature through the end of 2019.1 Introduction1.1 Alkyne-Carbonyl Coupling Pathways1.2 Coupling/Cyclization Cascades Using the Alkynyl Prins Reaction2 Alkynyl Prins Annulation (Oxocarbenium Electrophiles)2.1 Early Work2.2 Halide as Terminal Nucleophile2.3 Oxygen as Terminal Nucleophile2.4 Arene as Terminal Nucleophile (Intermolecular)2.5 Arene Terminal Nucleophile (Intramolecular)2.6 Cyclizations Terminated by Elimination3 Synthetic Utility of Alkynyl Prins Annulation3.1 Alkynyl Prins-Mediated Synthesis of Dienes for a [4+2] Cyclo­- addition­-Oxidation Sequence3.2 Alkynyl Prins Cyclization Adducts as Nazarov Cyclization Precursors3.3 Alkynyl Prins Cyclization in Natural Product Synthesis4 Alkynyl Aza-Prins Annulation4.1 Iminium Electrophiles4.2 Activated Iminium Electrophiles5 Alkynyl Aza-Prins Cyclizations in Natural Product Synthesis6 Summary and Outlook


2020 ◽  
Vol 37 (11) ◽  
pp. 1436-1453 ◽  
Author(s):  
Nathanyal J. Truax ◽  
Daniel Romo

Various synthetic strategies have been developed to explore natural products as an enduring source of chemical information useful for probing biological relevant chemical space and impacting drug discovery.


2018 ◽  
Vol 5 (1) ◽  
pp. 132-150 ◽  
Author(s):  
Pengquan Chen ◽  
Yuecheng Wu ◽  
Shifa Zhu ◽  
Huanfeng Jiang ◽  
Zhiqiang Ma

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


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