Asymmetric Synthesis of Bioactive Lactones and the Development of a Catalytic Asymmetric Synthesis of α-Aryl Ketones

Asymmetric Synthesis of Bioactive Lactones and the Development of a Catalytic Asymmetric Synthesis of α-Aryl Ketones PDF Author: Robert Doran
Publisher: Springer
ISBN: 3319205447
Category : Science
Languages : en
Pages : 202

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Book Description
This thesis addresses two fundamental areas in contemporary organic chemistry: synthesis of natural products and catalytic asymmetric synthesis. Firstly, a new methodology, developed by our research group, which allows the asymmetric synthesis of lactones, a structural unit ubiquitous in natural products, was utilised in the synthesis of a number of natural product analogues that showed significant biological activity. Secondly, the development of a catalytic asymmetric synthesis of a key structural motif present in a number of natural products and pharmaceuticals was accomplished. During the course of this work we discovered dual stereo control, which is significant because it allows the configuration of a new stereo centre to be controlled by a simple change of proton source.

Asymmetric Synthesis of Bioactive Lactones and the Development of a Catalytic Asymmetric Synthesis of α-Aryl Ketones

Asymmetric Synthesis of Bioactive Lactones and the Development of a Catalytic Asymmetric Synthesis of α-Aryl Ketones PDF Author: Robert Doran
Publisher: Springer
ISBN: 3319205447
Category : Science
Languages : en
Pages : 202

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Book Description
This thesis addresses two fundamental areas in contemporary organic chemistry: synthesis of natural products and catalytic asymmetric synthesis. Firstly, a new methodology, developed by our research group, which allows the asymmetric synthesis of lactones, a structural unit ubiquitous in natural products, was utilised in the synthesis of a number of natural product analogues that showed significant biological activity. Secondly, the development of a catalytic asymmetric synthesis of a key structural motif present in a number of natural products and pharmaceuticals was accomplished. During the course of this work we discovered dual stereo control, which is significant because it allows the configuration of a new stereo centre to be controlled by a simple change of proton source.

Catalytic Asymmetric Synthesis

Catalytic Asymmetric Synthesis PDF Author: Takahiko Akiyama
Publisher: John Wiley & Sons
ISBN: 1119736412
Category : Science
Languages : en
Pages : 798

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Book Description
Catalytic Asymmetric Synthesis Seminal text presenting detailed accounts of the most important catalytic asymmetric reactions known today This book covers the preparation of enantiomerically pure or enriched chemical compounds by use of chiral catalyst molecules. While reviewing the most important catalytic methods for asymmetric organic synthesis, this book highlights the most important and recent developments in catalytic asymmetric synthesis. Edited by two well-qualified experts, sample topics covered in the work include: Metal catalysis, organocatalysis, photoredox catalysis, enzyme catalysis C–H bond functionalization reactions Carbon–carbon bond formation reactions, carbon–halogen bond formation reactions, hydrogenations, polymerizations, flow reactions Axially chiral compounds Retaining the best of its predecessors but now thoroughly up to date with the important and recent developments in catalytic asymmetric synthesis, the 4th edition of Catalytic Asymmetric Synthesis serves as an excellent desktop reference and text for researchers and students, from upper-level undergraduates all the way to experienced professionals in industry or academia.

Asymmetric and Selective Biocatalysis

Asymmetric and Selective Biocatalysis PDF Author: Jose M. Palomo
Publisher: MDPI
ISBN: 3038978469
Category : Science
Languages : en
Pages : 154

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Book Description
This Issue contains one communication, six articles, and two reviews. The communication from Paola Vitale et al. represents a work where whole cells were used as biocatalysts for the reduction of optically active chloroalkyl arylketones followed by a chemical cyclization to give the desired heterocycles. Among the various whole cells screened (baker’s yeast, Kluyveromyces marxianus CBS 6556, Saccharomyces cerevisiae CBS 7336, Lactobacillus reuteri DSM 20016), baker’s yeast provided the best yields and the highest enantiomeric ratios (95:5) in the bioreduction of the above ketones. In this respect, valuable chiral non-racemic functionalized oxygen-containing heterocycles (e.g., (S)-styrene oxide, (S)-2-phenyloxetane, (S)-2-phenyltetrahydrofuran), amenable to be further elaborated on, can be smoothly and successfully generated from their prochiral precursors. Studies about pure biocatalysts with mechanistical studies, application in different reactions, and new immobilization methods for improving their stability were reported in five different articles. The article by Su-Yan Wang et al. describes the cloning, expression, purification, and characterization of an N-acetylglucosamine 2-epimerase from Pedobacter heparinus (PhGn2E). For this, several N-acylated glucosamine derivatives were chemically synthesized and used to test the substrate specificity of the enzyme. The mechanism of the enzyme was studied by hydrogen/deuterium NMR. The study at the anomeric hydroxyl group and C-2 position of the substrate in the reaction mixture confirmed the epimerization reaction via ring-opening/enolate formation. Site-directed mutagenesis was also used to confirm the proposed mechanism of this interesting enzyme. The article by Forest H. Andrews et al. studies two enzymes, benzoylformate decarboxylase (BFDC) and pyruvate decarboxylase (PDC), which catalyze the non-oxidative decarboxylation of 2-keto acids with different specificity. BFDC from Pseudomonas putida exhibited very limited activity with pyruvate, whereas the PDCs from S. cerevisiae or from Zymomonas mobilis showed virtually no activity with benzoylformate (phenylglyoxylate). After studies using saturation mutagenesis, the BFDC T377L/A460Y variant was obtained, with 10,000-fold increase in pyruvate/benzoylformate. The change was attributed to an improvement in the Km value for pyruvate and a decrease in the kcat value for benzoylformate. The characterization of the new catalyst was performed, providing context for the observed changes in the specificity. The article by Xin Wang et al. compares two types of biocatalysts to produce D-lysine L-lysine in a cascade process catalyzed by two enzymes: racemase from microorganisms that racemize L-lysine to give D,L-lysine and decarboxylase that can be in cells, permeabilized cells, and the isolated enzyme. The comparison between the different forms demonstrated that the isolated enzyme showed the higher decarboxylase activity. Under optimal conditions, 750.7 mmol/L D-lysine was finally obtained from 1710 mmol/L L-lysine after 1 h of racemization reaction and 0.5 h of decarboxylation reaction. D-lysine yield could reach 48.8% with enantiomeric excess (ee) of 99%. In the article by Rivero and Palomo, lipase from Candida rugosa (CRL) was highly stabilized at alkaline pH in the presence of PEG, which permitted its immobilization for the first time by multipoint covalent attachment on different aldehyde-activated matrices. Different covalent immobilized preparation of the enzyme was successfully obtained. The thermal and solvent stability was highly increased by this treatment, and the novel catalysts showed high regioselectivity in the deprotection of per-O-acetylated nucleosides. The article by Robson Carlos Alnoch et al. describes the protocol and use of a new generation of tailor-made bifunctional supports activated with alkyl groups that allow the immobilization of proteins through the most hydrophobic region of the protein surface and aldehyde groups that allows the covalent immobilization of the previously adsorbed proteins. These supports were especially used in the case of lipase immobilization. The immobilization of a new metagenomic lipase (LipC12) yielded a biocatalyst 3.5-fold more active and 5000-fold more stable than the soluble enzyme. The PEGylated immobilized lipase showed high regioselectivity, producing high yields of the C-3 monodeacetylated product at pH 5.0 and 4 °C. Hybrid catalysts composed of an enzyme and metallic complex are also treated in this Special Issue. The article by Christian Herrero et al. describes the development of the Mn(TpCPP)-Xln10A artificial metalloenzyme, obtained by non-covalent insertion of Mn(III)-meso-tetrakis(p-carboxyphenyl)porphyrin [Mn(TpCPP), 1-Mn] into xylanase 10A from Streptomyces lividans (Xln10A). The complex was found able to catalyze the selective photo-induced oxidation of organic substrates in the presence of [RuII(bpy)3]2+ as a photosensitizer and [CoIII(NH3)5Cl]2+ as a sacrificial electron acceptor, using water as oxygen atom source. The two published reviews describe different subjects with interest in the fields of biocatalysis and mix metallic-biocatalysis, respectively. The review by Anika Scholtissek et al. describes the state-of-the-art regarding ene-reductases from the old yellow enzyme family (OYEs) to catalyze the asymmetric hydrogenation of activated alkenes to produce chiral products with industrial interest. The dependence of OYEs on pyridine nucleotide coenzyme can be avoided by using nicotinamide coenzyme mimetics. In the review, three main classes of OYEs are described and characterized. The review by Yajie Wang and Huimin Zhao highlights some of the recent examples in the past three years that combine transition metal catalysis with enzymatic catalysis. With recent advances in protein engineering, catalyst synthesis, artificial metalloenzymes, and supramolecular assembly, there is great potential to develop more sophisticated tandem chemoenzymatic processes for the synthesis of structurally complex chemicals. In conclusion, these nine publications give an overview of the possibilities of different catalysts, both traditional biocatalysts and hybrids with metals or organometallic complexes to be used in different processes—particularly in synthetic reactions—under very mild reaction conditions.

Halogen Bonding in Solution

Halogen Bonding in Solution PDF Author: Stefan Huber
Publisher: John Wiley & Sons
ISBN: 3527347313
Category : Technology & Engineering
Languages : en
Pages : 418

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Book Description
Long-awaited on the importance of halogen bonding in solution, demonstrating the specific advantages in various fields - from synthesis and catalysis to biochemistry and electrochemistry! Halogen bonding (XB) describes the interaction between an electron donor and the electrophilic region of a halogen atom. Its applicability for molecular recognition processes long remained unappreciated and has mostly been studied in solid state until recently. As most physiological processes and chemical reactions take place in solution, investigations in solutions are of highest relevance for its use in organic synthesis and catalysis, pharmaceutical chemistry and drug design, electrochemistry, as well as material synthesis. Halogen Bonding in Solution gives a concise overview of halogen bond interactions in solution. It discusses the history and electronic origin of halogen bonding and summarizes all relevant examples of its application in organocatalysis. It describes the use of molecular iodine in catalysis and industrial applications, as well as recent developments in anion transport and binding. Hot topic: Halogen bonding is an important interaction between molecules or within a molecule. The field has developed considerably in recent years, with numerous different approaches and applications having been published. Unique: There are several books on halogen bonding in solid state available, but this will be the first one focused on halogen bonding in solution. Multi-disciplinary: Summarizes the history and nature of halogen bonding in solution as well as applications in catalysis, anion recognition, biochemistry, and electrochemistry. Aimed at facilitating exciting future developments in the field, Halogen Bonding in Solution is a valuable source of information for researchers and professionals working in the field of supramolecular chemistry, catalysis, biochemistry, drug design, and electrochemistry.

Artificial Metalloenzymes and MetalloDNAzymes in Catalysis

Artificial Metalloenzymes and MetalloDNAzymes in Catalysis PDF Author: Montserrat Diéguez
Publisher: John Wiley & Sons
ISBN: 3527804072
Category : Technology & Engineering
Languages : en
Pages : 1200

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Book Description
An important reference for researchers in the field of metal-enzyme hybrid catalysis Artificial Metalloenzymes and MetalloDNAzymes in Catalysis offers a comprehensive review of the most current strategies, developed over recent decades, for the design, synthesis, and optimization of these hybrid catalysts as well as material about their application. The contributors—noted experts in the field—present information on the preparation, characterization, and optimization of artificial metalloenzymes in a timely and authoritative manner. The authors present a thorough examination of this interesting new platform for catalysis that combines the excellent selective recognition/binding properties of enzymes with transition metal catalysts. The text includes information on the various applications of metal-enzyme hybrid catalysts for novel reactions, offers insights into the latest advances in the field, and contains an informative perspective on the future: Explores the development of artificial metalloenzymes, the modern and strongly evolving research field on the verge of industrial application Contains a comprehensive reference to the research area of metal-enzyme hybrid catalysis that has experienced tremendous growth in recent years Includes contributions from leading researchers in the field Shows how this new catalysis combines the selective recognition/binding properties of enzymes with transition metal catalysts Written for catalytic chemists, bioinorganic chemists, biochemists, and organic chemists, Artificial Metalloenzymes and MetalloDNAzymes in Catalysis offers a unique reference to the fundamentals, concepts, applications, and the most recent developments for more efficient and sustainable synthesis.

Non-Metal Catalyzed Synthesis

Non-Metal Catalyzed Synthesis PDF Author: Yunfei Du
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110985470
Category : Science
Languages : en
Pages : 360

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Book Description
Non-metal catalysis may provide new and green methods for obtaining bioactive heterocycles. Many catalysts contain metals, which can be toxic, energy intensive to remove, and require mining of the source materials. By utilizing metal-free catalysts we avoid these issues. This book explores the use of non-metal catalysts when synthesizing various heterocyclic structures with bioactivity.

Dienamine Catalysis for Organic Synthesis

Dienamine Catalysis for Organic Synthesis PDF Author: Kengadarane Anebouselvy
Publisher: Royal Society of Chemistry
ISBN: 1782620907
Category :
Languages : en
Pages : 206

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Book Description
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.

Multicomponent Reactions towards Heterocycles

Multicomponent Reactions towards Heterocycles PDF Author: Erik Van der Eycken
Publisher: John Wiley & Sons
ISBN: 3527349081
Category : Science
Languages : en
Pages : 626

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Book Description
Presents a wide-ranging overview of essential topics and recent advances in MCR chemistry Heterocycles are a central component in natural product chemistry, pharmaceuticals, agrochemicals, and material science. New synthetic methodologies integrating the sequencing of multicomponent reactions (MCRs) are today being used for the rapid synthesis of diversified heterocycles in just one step. Multicomponent Reactions towards Heterocycles presents an up-to-date summary MCR chemistry with a focus on the conjugation between modern synthetic methodologies and MCRs. Featuring contributions by leaders in the field, this comprehensive resource highlights applications of MCRs in natural products and intermediate synthesis, discusses current trends and future prospects in MCR chemistry, outlines novel multicomponent procedures, and more. The authors provide the practical information required for designing new reaction strategies and mechanisms, covering topics including MCR-based green synthetic methods, cyclization and cycloaddition reactions, heterocycle multicomponent syntheses in a continuous flow, catalytic alkynoyl generation, MCR synthesis of saturated heterocycles, and C–H functionalization and multicomponent reactions. Provides a thorough overview of heterocycles as input in multicomponent reactions Discusses recent advances in the field of MCR chemistry and progress in the synthesis and functionalization of heterocycles Demonstrates the use of MCRs to simplify synthetic design and achieve complexity and diversity in novel bioactive molecules Highlights examples of multicomponent polymerizations, target-oriented synthesis, and applications of MCR in medicinal chemistry Explains the methodology of using on-resin MCRs to produce heterocycle compounds Illustrating the key role of MCRs towards heterocycles in natural product synthesis, drug discovery, organic synthesis, and other applications, Multicomponent Reactions towards Heterocycles is required reading for synthetic chemists in academia and industry alike.

Chemistry of Biologically Potent Natural Products and Synthetic Compounds

Chemistry of Biologically Potent Natural Products and Synthetic Compounds PDF Author: Shahid Ul-Islam
Publisher: John Wiley & Sons
ISBN: 1119640342
Category : Science
Languages : en
Pages : 434

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Book Description
In view of their promising biological and pharmaceutical activities, natural product inspired and heterocyclic compounds have recently gained a reputation in the field of medicinal chemistry. Over the past decades, intensive research efforts have been ongoing to understand the synthesis, biochemistry and engineering involved in their preparation and action mechanisms. Several novel natural product derivatives, heterocyclic and other synthetic compounds, have been reported to have shown interesting biological activities including anticancer, antimicrobial, anti-inflammatory, anti-glycemic, anti-allergy and antiviral etc. Chemistry of Biologically Potent Natural Products and Synthetic Compounds provides up-to-date information on new developments and most recent medicinal applications of the natural products and derivatives, as well as the chemistry and synthesis of heterocyclic and other related compounds.

Iodine Catalysis in Organic Synthesis

Iodine Catalysis in Organic Synthesis PDF Author: Kazuaki Ishihara
Publisher: John Wiley & Sons
ISBN: 3527348298
Category : Technology & Engineering
Languages : en
Pages : 452

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Book Description
Iodine Catalysis in Organic Synthesis The first book of its kind to highlight iodine as a sustainable alternative to conventional transition metal catalysis Iodine Catalysis in Organic Synthesis provides detailed coverage of recent advances in iodine chemistry and catalysis, focusing on the utilization of various iodine-containing compounds as oxidative catalysts. Featuring contributions by an international panel of leading research chemists, this authoritative volume explores the development of environmentally benign organic reactions and summarizes catalytic transformations of molecular iodine and iodine compounds such as hypervalent organoiodine and inorganic iodine salts. Readers are first introduced to the history of iodine chemistry, the conceptual background of homogeneous catalysis, and the benefits of iodine catalysis in comparison with transition metals. Next, chapters organized by reaction type examine enantioselective transformations, catalytic reactions involving iodine, catalyst states, oxidation in iodine and iodine catalyses, and catalytic reactions based on halogen bonding. Practical case studies and real-world examples of different applications in organic synthesis and industry are incorporated throughout the text. An invaluable guide for synthetic chemists in both academic and industrial laboratories, Iodine Catalysis in Organic Synthesis: Provides a thorough overview of typical iodine-catalyzed reactions, catalyst systems, structures, and reactivity Explores promising industrial applications of iodine-based reagents for organic synthesis Highlights the advantages iodine catalysis has over classical metal-catalyzed reactions Discusses sustainable and eco-friendly methods in hypervalent iodine chemistry Edited by two world authorities on the catalytic applications of organoiodine compounds, Iodine Catalysis in Organic Synthesis is required reading for catalytic, organic, and organometallic chemists, medicinal and pharmaceutical chemists, industrial chemists, and academic researchers and advanced students in relevant fields.