Donor Acceptor Cyclopropanes As Building Blocks For The Synthesis Of Natural Product Scaffolds
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Author | : Sinan Gai |
Publisher | : |
Total Pages | : 496 |
Release | : 2018 |
Genre | : |
ISBN | : |
The first chapter of this thesis provides an introduction to natural products and describes how they are a valuable source of bioactive compounds, which feature heavily in clinically used drugs. The recently reported bioactive natural product maoecrystal V was introduced followed by the chemistry of cyclopropanes, which were intended to be used in the synthesis of maoecrystal V.Synthetic strategies towards the synthesis of maoecrystal V were investigated in chapter 2. A retrosynthetic analysis of maoecrystal V was proposed, which featured a cyclopropane ring expansion. Using a model system, the key step, an intermolecular Diels-Alder cycloaddition was used to construct the [2.2.2]-bicyclooctane scaffold of maoecrystal V. Concurrently to this work, Baran and co-workers completed the synthesis of maoecrystal V and found that it possessed little to no bioactivity against a wide range of cancer cell lines.An introduction to spiroketals and the less common benzannulated spiroketals followed by the methodology to construct them are described in chapter 3. Based on some preliminary results from another study, attention was turned to utilising donor-acceptor cyclopropanes in the synthesis of benzannulated n,5-spiroketals (n = 6 or 5), which are found in numerous bioactive natural products.
Author | : Florian de Nanteuil |
Publisher | : Springer |
Total Pages | : 329 |
Release | : 2015-09-26 |
Genre | : Science |
ISBN | : 3319230069 |
This thesis presents a general approach to accessing nitrogen-substituted hetero- and carbocycles. In short, the annulation reactions developed in the thesis make it possible to access nitrogen-substituted four-, five- and six-membered rings, all essential building blocks for the synthesis of bioactive molecules. Many natural products display a saturated polycyclic core allowing a well-defined arrangement of functional groups in space. As such, they can interact with biological targets with a high degree of affinity and selectivity, surpassing many synthetic drugs. Nevertheless, the efficient synthesis of such complex ring systems poses a challenge for organic chemistry. Through careful tuning of the electronic properties of a nitrogen donor group and a diester acceptor group, the first [3+2] annulation reaction between aminocyclopropanes and enol ethers or carbonyl compounds is now possible. The reaction proceeded under mild catalytic conditions, and the building blocks obtained can be found at the core of bioactive alkaloids, drugs such as Ramipril and biomolecules such as DNA and RNA. Thanks to the dynamic kinetic asymmetric annulation of aminocyclopropanes with enol ethers and aldehydes, access to enantioenriched compounds is also now possible. Lastly, a synthesis of donor-acceptor aminocyclobutanes via [2+2] cycloaddition using a cheap iron catalyst was developed, allowing them to be used in [4+2] annulations to access cyclohexylamines.
Author | : Kengadarane Anebouselvy |
Publisher | : Royal Society of Chemistry |
Total Pages | : 220 |
Release | : 2018-03-02 |
Genre | : Science |
ISBN | : 1782620907 |
In the last decade a new era in asymmetric catalysis has been realised by the discovery of L-proline induced chiral enamines from carbonyls. Inspired by this, researchers have developed many other primary catalytic species in situ, more recently secondary catalytic species such as aminals have been identified for use in asymmetric synthesis. High-yielding asymmetric synthesis of bioactive and natural products through mild catalysis is an efficient approach in reaction engineering. In the early days, synthetic chemists mainly focused on the synthesis of complex molecules, with less attention on the reaction efficiency and eco-friendly conditions. Recent investigations have been directed towards the development of atom economy, eco-friendly and enantioselective synthesis for more targeted and efficient synthesis. Building on the momentum of this rapidly expanding research area, Dienamine catalysis for organic synthesis will provide a comprehensive introduction, from the preformed species, in situ generation and onto their applications in the synthesis of bioactive molecules and natural products.
Author | : Junzo Otera |
Publisher | : John Wiley & Sons |
Total Pages | : 632 |
Release | : 2008-11-21 |
Genre | : Science |
ISBN | : 3527613277 |
The carbonyl group is undoubtedly one of the most important functional groups in organic chemistry, both in its role as reactive center for synthesis or derivatisation and as crucial feature for special structural or physiological properties. Vast and profound progress has been made in all aspects modern carbonyl chemistry. These achievements are, however, rather dispersed in the literature and it is often not easy for the researcher obtain a comprehensive overview of a relevant topic. Modern Carbonyl Chemistry overcomes this inconvenience by collating the information for appropriate themes. In this work internationally renowned experts and leaders in the field have surveyed recent aspects and modern features in carbonyl chemistry, such as cascade-reactions, one-pot-syntheses, recognition, or site differentiation.
Author | : Prabal Banerjee |
Publisher | : John Wiley & Sons |
Total Pages | : 469 |
Release | : 2024-05-06 |
Genre | : Science |
ISBN | : 3527349871 |
Facilitate milder, simpler reactions in organic synthesis with this cutting-edge family of building blocks Donor-Accepted Cyclopropanes, or DACs, have attracted a resurgence of interest from organic chemists in recent decades for their role in facilitating various reactions such as cycloadditions, annulations, ring-opening and enantioselective transformations. The structural arrangement of DACs leads to milder, simpler reaction conditions, which have made them indispensable for a range of fundamentally and industrially important processes. Donor-Acceptor Cyclopropanes in Organic Synthesis covers comprehensively the chemistry and applications of this compound class. The result is an invaluable guide for any researcher looking to bring DACs to bear in their own areas of research or development. Readers will also find: A brief introduction of the history and reactivity of DACs Detailed discussion of reactions including Lewis acid-catalyzed cycloadditions, metal-free activation, asymmetric transformations, organocatalysis, and many more Application of DACs in natural product synthesis and pharmaceutical/agrochemical research Donor-Acceptor Cyclopropanes in Organic Synthesis is ideal for organic chemists, experts in catalysis, pharmaceutical researchers, and any other scientists interested in facilitating milder, simpler reactions.
Author | : Matthew L. Crawley |
Publisher | : John Wiley & Sons |
Total Pages | : 386 |
Release | : 2012-05-14 |
Genre | : Science |
ISBN | : 1118309839 |
This book focuses on the drug discovery and development applications of transition metal catalyzed processes, which can efficiently create preclinical and clinical drug candidates as well as marketed drugs. The authors pay particular attention to the challenges of transitioning academically-developed reactions into scalable industrial processes. Additionally, the book lays the groundwork for how continued development of transition metal catalyzed processes can deliver new drug candidates. This work provides a unique perspective on the applications of transition metal catalysis in drug discovery and development – it is a guide, a historical prospective, a practical compendium, and a source of future direction for the field.
Author | : Marco Brito-Arias |
Publisher | : Springer Science & Business Media |
Total Pages | : 362 |
Release | : 2007-03-12 |
Genre | : Science |
ISBN | : 0387707921 |
This book contains the best known approaches for preparing the main types of glycosides in a short and comprehensive study. It also includes synthetic pathways of challenging glycosides known as antiviral or antineoplasic drugs, or synthetic substrates used for enzymatic detection including those used as substrates for detection of gene markers in plant biotechnology. Special attention is made on the structural characterization, providing the basic tools for the structural assignment through NMR, X-Ray and mass spectra techniques. Some of the chapters cover strategies for preparation of antiviral and antineoplasic drugs included in a drug design course.
Author | : Xuefeng Jiang |
Publisher | : Springer Nature |
Total Pages | : 475 |
Release | : 2019-08-28 |
Genre | : Science |
ISBN | : 3030255980 |
The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field.
Author | : Catherine E. Housecroft |
Publisher | : MDPI |
Total Pages | : 264 |
Release | : 2021-08-18 |
Genre | : Science |
ISBN | : 3036514635 |
This Special Issue is one of the first for the new MDPI flagship journal Chemistry (ISSN 2624-8549) which has a broad remit for publishing original research in all areas of chemistry. The theme of this issue is Supramolecular Chemistry in the 3rd Millennium and I am sure that this topic will attract many exciting contributions. We chose this topic because it encompasses the unity of contemporary pluridisciplinary science, in which organic, inorganic, physical and theoretical chemists work together with molecular biologists and physicists to develop a systems-level understanding of molecular interactions. The description of supramolecular chemistry as 'chemistry beyond the molecule' (Jean-Marie Lehn, Nobel Lecture and Gautam R. Desiraju, Nature, 2001, 412, 397) addresses the wide variety of weak, non-covalent interactions that are the basis for the assembly of supramolecular architectures, molecular receptors and molecular recognition, programed molecular systems, dynamic combinatorial libraries, coordination networks and functional supramolecular materials. We welcome submissions from all disciplines involved in this exciting and evolving area of science.
Author | : Ronald Michael Painter |
Publisher | : Stanford University |
Total Pages | : 110 |
Release | : 2011 |
Genre | : |
ISBN | : |
The chemoselective oxidation of vicinal diols to α-hydroxyketones is a challenge in organic syntheses because not only does the diol need to be oxidized selectively to a monocarbonyl compound, but diols are also prone to overoxidation and oxidative cleavage. Employing a cationic palladium complex, [(neocuproine)Pd(OAc)]2(OTf)2, we were able to demonstrate the selective oxidation of glycerol to dihydroxyacetone mediated by either benzoquinone or O2 as the terminal oxidant, an accomplishment that has little precedent in homogeneous catalysis. Mechanistic studies were undertaken to uncover the nature of this remarkable chemoselectivity. Kinetic and deuterium-labeling studies implicate reversible β-hydride elimination from isomeric Pd alkoxides and turnover-limiting displacement of the dihydroxyacetone product by benzoquinone. We successfully extended this methodology to other terminal 1,2-diols and symmetric vicinal 1,2-diols and have carried out aerobic oxidation of these substrates catalyzed by 1. Examination of the reactivity of 1 with conformationally-restricted 1,2-cyclohexanediols suggests that the diol must chelate to the Pd center for effective oxidation to the hydroxyketone product. In a separate project, we have also investigated the electrocatalytic reduction of dioxygen by several dinuclear copper complexes, an important reaction for fuel cell applications.