Download or read book Studies Towards the Synthesis of the Heterocyclic Scaffolds of Biologically Active Natural Products written by Sylvia Gang and published by . This book was released on 2009 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Bioactive Scaffolds written by Rakesh Kumar Sharma and published by Walter de Gruyter GmbH & Co KG. This book was released on 2022-08-22 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-carbon and carbon-heteroatom bond-forming reactions are the backbone of synthetic organic chemistry. Scientists are constantly developing and improving these techniques in order to maximize the diversity of synthetically available molecules. These techniques must be developed in a sustainable manner in order to limit their environmental impact. This book highlights green bond forming reactions for bioactive scaffolds.

Download or read book Green Synthetic Approaches for Biologically Relevant Heterocycles written by Goutam Brahmachari and published by Elsevier. This book was released on 2021-02-26 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: Green Synthetic Approaches for Biologically Relevant Heterocycles, Second Edition, Volume One: Advanced Synthetic Techniques reviews this significant group of organic compounds within the context of sustainable methods and processes, expanding on the first edition with fully updated coverage and a whole range of new chapters. Volume One explores advanced synthetic techniques, with each chapter presenting in-depth coverage of various green protocols for the synthesis of a wide variety of bioactive heterocycles that are classified on the basis of ring-size and/or the presence of heteroatoms. Techniques covered range from high pressure cycloaddition reactions and microwave irradiation to sustainable one-pot domino reactions. This updated edition is an essential resource on sustainable approaches for academic researchers, R&D professionals, and students working across medicinal, organic, natural product and green chemistry. Provides fully updated coverage of the field of greener heterocycle synthesis Includes new chapters on varied multicomponent reactions, alongside both traditional and novel approaches Presents information in an accessible style with an emphasis on sustainability

Download or read book Heterocyclic Scaffolds I written by Bimal K. Banik and published by Springer. This book was released on 2010-06-01 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: B. Alcaide ∙ P. Almendros: Novel Aspects on the Preparation of Spirocyclic and Fused Unsual β-Lactams.- S.S. Bari ∙ A. Bhalla: Spirocyclic β-Lactams: Synthesis and Biological Evaluation of Novel Heterocycles.- L. Troisi ∙ C. Granito ∙ E. Pindinelli: Novel and Recent Synthesis and Applications of β-Lactams.- C. Palomo ∙ M. Oiarbide: β-Lactams Ring Opening: A Useful Entry to Amino Acids and Relevant Nitrogen-Containing Compounds.- B. Mandal ∙ P. Ghosh ∙ B. Basu: Recent Approaches Towards Solid Phase Synthesis of β-Lactams.- A.Arrieta ∙ B. Lecea ∙ F.P. Cossio: Computational Studies on the Synthesis of β-Lactams Via [ 2+2] Thermal Cycloadditions.- B. K. Banik ∙ I. Banik ∙ F. F. Becker: Novel Anticancer β-Lactams

Download or read book Preparation of 5 6 7 8 tetrahydro 1 6 naphthyridines and Other Heterocyclic Scaffolds and Their Application in Library Synthesis written by Ya Zhou and published by . This book was released on 2008 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Small, polyfunctionalized heterocycles have attracted significant attention in the design of biologically active compounds in the drug discovery enterprise. Research in the area of combinatorial synthesis employing heterocycles as scaffolds for library development has become very prominent. Pyridine-containing heterocycles, such as tetrahydronaphthyridines, have been shown to possess a variety of biologic activities. Previous work in our group developed an inverse-electron-demand Diets-Alder (IEDDA) strategy to prepare the 1,2,3,4-tetrahydro-1,5-naphthyridines, however, the preparation of the other tetrahydronaphthyridine analogues could not be achieved via this IEDDA strategy. Thus, metal-catalyzed [2 + 2 + 2] cyclizations between a nitrite and two alkynes were investigated in both intermolecular and intramolecular reactions, which have the potential to prepare all the tetrahydronaphthyridine isomers. To determine optimal conditions, different transition metals (Co, Zr, Ni, Ir, Ru, and Au), as well as reaction conditions (thermal heating, photochemical activation, and microwave irradiation) were screened. The best results were achieved when CpCo(CO) 2 was employed as catalyst, under microwave irradiation in chlorobenzene. Using the optimized microwave-promoted conditions, the intermolecular cyclizations between amino alkynyl nitriles and alkynes gave the desired 5,6,7,8-tetrahydro-1,6-naphthyridines in modest yields, while the intramolecular cyclizations of dialkynyl aminonitrile precursors afforded dihydropyran ring-fused tetrahydronaphthyridines in excellent yields. Finally, a heterocyclic natural product, naringenin, was investigated for its suitability as a library scaffold. Belonging to the flavonone class, naringenin is characterized by the rigid tricyclic benzopyran core with three phenols at C-5, C-7 and C-4' positions. Recent epidemiological studies showed increasing evidence for the anticancer and antiatherogenic properties of this natural product. Its rigid, densely functionalized tricyclic scaffold is an attractive structure for discovering novel bioactive molecules. Thus, suitable chemistries were explored on these scaffolds in an effort to define regioselective transformations of the phenolic groups through palladium catalyzed cross-coupling chemistry which could be applied to library development.

Download or read book Privileged Scaffolds in Medicinal Chemistry written by Stefan Bräse and published by Royal Society of Chemistry. This book was released on 2015-11-20 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the various classes of privileged scaffolds and covers the history of their discovery and use.

Download or read book Multicomponent Reactions written by K.L. Ameta, Ph.D. and published by CRC Press. This book was released on 2017-09-20 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely book provides a succinct summary of methods for the synthesis of bioactive heterocycles using a multicomponent reaction (MCR) approach. The majority of pharmaceuticals and biologically active agrochemicals are heterocycles while countless additives and modifiers used in industrial applications are heterocyclic in nature. With the recent introduction of high-throughput biological evaluation, the importance of MCRs for drug discovery has been recognized and considerable efforts have been focused especially on the design and development of multi-component procedures for the generation of various bioactive heterocycles due to their significant therapeutic potential.

Download or read book Studies Directed to the Total Synthesis of Biologically Active Natural Products written by Spiros I. Liras and published by . This book was released on 1990 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Greener Synthesis of Organic Compounds written by Ahindra Nag and published by CRC Press. This book was released on 2022-05-30 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an interdisciplinary, integrative overview of environmental problem-solving using mild reaction conditions, green reagents, waste free and energy efficient synthesis in both industry and academic world. Discussions include a broad, integrated perspective on sustainability, integrated risk, multi-scale changes and impacts taking place within ecosystems worldwide. Features: This book serves as a reference book for scientific investigators who need to do greener synthesis of organic compounds, drugs and natural products under mild reaction condition using green reagents, eco-friendly catalysts and benign reaction mediums over traditional synthetic processes which is a key driving force of scientists. Greener synthesis of multiple value-added heterocycles opens up a new horizon towards the organic catalysis and for this purpose, development of natural resources acts as an effective catalyst. Using environmentally friendly reaction medium e.g. ACC, WETSA, WEBSA have been used for the synthesis of some crucial heterocyclic scaffolds such as bisenols and 2-amino-4H-pyrans, tetraketones, pyrans, and biaryls. This book can also be used as a textbook for graduate and post graduate level courses for students. Furthermore, the problems with answers in book will add better understanding for students.

Download or read book Studies in Natural Products Chemistry written by Atta-ur Rahman and published by Elsevier. This book was released on 2016-11-24 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural products in the plant and animal kingdom offer a huge diversity of chemical structures that are the result of biosynthetic processes that have been modulated over the millennia through genetic effects. With the rapid developments in spectroscopic techniques and accompanying advances in high-throughput screening techniques, it has become possible to isolate and then determine the structures and biological activity of natural products rapidly, thus opening up exciting opportunities in the field of new drug development to the pharmaceutical industry. This series covers the synthesis or testing and recording of the medicinal properties of natural products, providing cutting edge accounts of the fascinating developments in the isolation, structure elucidation, synthesis, biosynthesis and pharmacology of a diverse array of bioactive natural products. Focuses on the chemistry of bioactive natural products Contains contributions by leading authorities in the field Presents sources of new pharmacophores

Download or read book Strategies for the Synthesis of Scaffolds Found in Natural Products written by Renato A. Bauer and published by . This book was released on 2012 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major challenge to finding compounds that modulate protein function is the identification of chemical matter for screening. Although Nature provides excellent options for screening in the form of natural products, sufficient quantities can be difficult to obtain and characterize. Thus, chemical synthesis plays a lead role in providing molecules for screening, and chemists must ultimately decide what to synthesize based on the predicted value of the end products. We developed new synthetic strategies to access compounds for screening. In each case, natural products serve as an inspiration for the developed chemistry. First, a strategy was developed that provides access to scaffolds based on bioactive alkaloids and terpenoids. A key feature of this strategy is the use of transition metals to mediate the synthesis of multiple scaffolds from simple enynes and diynes. A t -butylsulfinamide group serves as a convenient tether to facilitate this chemistry. Principal component analysis (PCA) is used to analyze the relationship of our synthetic scaffolds to naturally occurring alkaloids and terpenoids. Then, a chemical reaction was studied that provides access to benzannulated medium rings inspired by natural products. In the developed reaction, three reagent classes (TsOH, Cu[BF 4 ] 2 , and Tf 2 0) were shown to polarize the carbonyl of a polycyclic cyclohexadienone and subsequently cause a cationic fragmentation reaction that generates an aromatic ring annulated to a medium ring. This process efficiently produces 7- to 11- membered rings while tolerating a variety of common functional groups. Work is presented on efforts to apply this reaction to the synthesis of two natural products, heliannuol A and puerol A.

Download or read book Synthesis Towards Biologically Active Natural Products written by and published by . This book was released on 2012 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Green Chemistry Synthesis of Bioactive Heterocycles written by K. L. Ameta and published by Springer. This book was released on 2014-06-17 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents a succinct summary of methods for the synthesis and biological activities of various different-sized bioactive heterocycles using different green chemistry synthetic methodologies, like microwave, ultrasonic, water mediated, ionic liquids, etc. The book also provides an insight of how green chemistry techniques are specific to the bioactive heterocyclic compounds.

Download or read book Complexity Generating Annulation Reactions in the Synthesis of Natural Products and Materials Scaffolds written by Robert Bergstrand Susick and published by . This book was released on 2020 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation encompasses several studies pertaining to natural product total synthesis, reaction methodology development, and organic materials. Given that natural product structures inspire the development of new agrochemicals and pharmaceuticals, their syntheses remain a worthwhile pursuit in organic chemistry. Furthermore, the successful completion of a total synthesis endeavor can confirm proposed molecular structures and biological activities, in addition to serving as a testing ground for new synthetic methods. Similarly, organic materials impact many areas of humanity, including technology, health, and energy conversion. Therefore, developing new reaction methodologies is crucial for expanding the architectures, and thereby properties, of organic materials. Specifically, photocatalysts and organic light-emitting diodes (OLEDs) often rely on photophysical properties imparted by N-containing polycyclic aromatic hydrocarbon (PAH) ligands. As such, new methods that provide access to unique N-containing heterocyclic scaffolds are highly desirable. Chapter one offers a current perspective on the field of natural product total synthesis. Although historically viewed as a highly competitive field, several recent syntheses demonstrate a growing spirit of collaboration in total synthesis. By forming alliances with chemists in other fields, industries, or laboratories, total synthesis chemists have made many breakthroughs that would arguably not have been possible if working independently. Chapter two describes our laboratory's total syntheses of several bioactive akuammiline alkaloids, including strictamine, 2(S)-cathafoline, akuammiline, -akuammigine, and 10-demethoxyvincorine. Our strategic approach to the natural products focused on the use of a modern variant of a classic reaction, the Fischer indolization, to install several rings and the common quaternary center found in each target. This strategy allowed for the first total syntheses of akuammilines bearing a methanoquinolizidine core, as well as those that bear vicinal quaternary centers. In addition, rearrangements of the methanoquinolizidine core were developed that allowed us to access pyrrolidinoindoline-containing akuammilines. Chapter three describes synthetic studies of the reactive intermediates 2,3-pyridyne and 4,5-pyrimidyne. Heterocycles bearing one or more nitrogen atom are privileged motifs in natural products and pharmaceuticals. Therefore, methodologies that decorate such heterocycles are of great interest to the synthetic and biological communities. Arynes are highly reactive, transient species that can efficiently build multiple bonds in a single transformation, and our lab is particularly interested in accessing new, heterocyclic arynes to study their reactivity. This study demonstrates the synthetic utility of 2,3-pyridyne and the undesired reactivity of a 4,5-pyrimidyne precursor. Chapter four describes synthetic studies toward the development of new methods to manipulate polypyridyl organometallic scaffolds. Ruthenium- and iridium-based polypyridyl organometallic complexes have been known for nearly a century and have broadly impacted the scientific community, including the areas of catalysis, bioimaging, and energy conversion. Despite decades of study, methods to synthesize polypyridyl ligands are limited to relatively few transformations, particularly when extending -conjugation. We detail the use of arynes to extend the conjugation of polypyridyl ligands "on-the-complex," thereby overcoming traditional limitations in ligand synthesis. We also disclose the first generation and trapping of a ligand-bound aryne on an organometallic complex. Chapter five describes the synthesis of a novel -extended carbazole ligand for the study of structure-property relationships in two-coordinate metal complexes. Recently, linear two-coordinate metal complexes of the general structure donor-metal-acceptor have been identified as promising dopants for OLEDs. Both the donor and acceptor ligand play a crucial role in tuning the photophysical properties of these complexes. However, donor ligands with extended -conjugation have not been studied in this context. Our approach leverages heterocyclic arynes to synthesize -extended donor ligands in a modular fashion, which can also apply to other PAHs. Subsequent photophysical studies of -extended two-coordinate metal complexes identify a new dopant that displays up to 80% photoluminescence efficiency.

Download or read book Heterocycles in Natural Product Synthesis written by Krishna C. Majumdar and published by John Wiley & Sons. This book was released on 2011-06-15 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling a gap on the market, this handbook and ready reference is unique in its discussion of the usefulness of various heterocyclic systems in the synthesis of natural products. Clearly structured for easy access to the information, each chapter is devoted to a certain class of heterocycle, providing a tabular presentation of the natural products to be covered containing the particular heterocyclic ring system along with their biological profile, occurrence and most important physical properties, backed by the appropriate references. In addition, the application of the heterocyclic system to the synthesis of natural products ic covered in detail. Of great interest to organic, natural products, medicinal and biochemists, as well as those working in the pharmaceutical and agrochemical industry.

Download or read book Studies Toward the Total Synthesis of Biologically Active Cyclodepsipeptides written by 彭向榮 and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Studies Toward the Total Synthesis of Biologically Active Cyclodepsipeptides" by 彭向榮, Heung-wing, Pang, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3122775 Subjects: Cyanobacteria Mollusks Natural products - Synthesis Organic compounds - Synthesis

Download or read book Total Synthesis of Bioactive Natural Products by Palladium Catalyzed Domino Cyclization of Allenes and Related Compounds written by Shinsuke Inuki and published by Springer. This book was released on 2011-11-30 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author has developed novel methodologies for highly efficient construction of functionalized heterocycles by palladium-catalyzed domino/cascade cyclization of allenes and related compounds containing appropriate nucleophilic group(s). Based on these methodologies, enantioselective total syntheses of bioactive natural products, pachastrissamine (26% overall yield in seven steps), lysergic acid (4.0% overall yield in fifteen steps), lysergol (3.6% overall yield in fifteen steps) and isolysergol (8.2% overall yield in eleven steps) have been achieved. These are more facile synthetic route than those previously reported. These findings would contribute to the development of efficient synthetic methods for biologically active compounds containing a complex structure.