The Assignment of the Absolute Configuration by NMR Using Chiral Derivatizing Agents


Book Description

Nuclear magnetic resonance spectroscopy (NMR) is a technique that uses the magnetic properties of atomic nuclei to obtain information about the structure and properties of molecules. Proton and Carbon NMR, focusing on 1H and 13C, constitute the most powerful spectroscopic method for structure determination of Organic molecules. Application of this methodology to the assignment of absolute configuration was initiated in the late sixties and now is a well-established method that allows the rapid determination of the absolute configuration of more than one dozen different classes of mono-, bi-, and trifunctional organic compounds. Its simplicity requires the derivatization of the compound with a chiral arylalkoxyacetic acid, and examination of their 1H- and/or 13C-NMR spectra. In The Assignment of the Absolute Configuration by NMR using Chiral Derivatizing Agents: A Practical Guide, Professor Ricardo Riguera and coauthors organize this cutting-edge NMR research, offering a short and usable guide that introduces the reader to the research with a plethora of details and examples. The book briefly explains the theoretical aspects behind this methodology, dedicating most of its space to covering the practical aspects of the assignment, as well as the selection of the most adequate auxiliary reagent and the single or double derivatization, the use of resins etc. Examples and spectra taken from the authors' own experiments are included to illustrate the methodology. Upper-level undergraduates, graduate students, and chemical and pharmaceutical researchers will find this guide useful for their studies.




The Assignment of the Absolute Configuration by NMR Using Chiral Derivatizing Agents


Book Description

Nuclear magnetic resonance spectroscopy (NMR spectroscopy) is a research technique that uses the magnetic properties of atomic nuclei to determine physical and chemical properties of atoms or the molecules in which they are contained. Proton NMR (1H NMR) is a technique that applies NMR spectroscopy specifically to the hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of that substance's molecules. The use of 1H NMR for the assignment of absolute configuration of organic compounds is a well-established technique. Recent research describes the technique's application to mono-, bi- and trifunctional compounds. In addition, several new auxiliary reagents, mono- and biderivatization procedures, on-resin methodologies and more recently, the use of 13C NMR, have been introduced to the field. In The Assignment of the Absolute Configuration by NMR Using Chiral Derivatizing Agents: A Practical Guide, eminent Professor of Organic Chemistry Ricardo Riguera organizes this cutting-edge NMR research. Professor Riguera offers a short and usable guide that introduces the reader to the research with a plethora of details and examples. The book briefly explains the theoretical aspects necessary for understanding the methodology, dedicating most of its space to covering the practical aspects of the assignment, with examples and spectra taken from the authors' own experiments. Upper-level undergraduates, graduate students, and chemical researchers will find this guide useful for their studies and practice.




Differentiation of Chiral Compounds Using NMR Spectroscopy


Book Description

An updated guide to the most current information available for determining how to use NMR spectroscopy to differentiate chiral compounds Differentiation of Chiral Compounds Using NMR Spectroscopy offers a thoroughly revised second edition to the essential volume that puts the focus on the chiral systems that are commercially available and have been widely vetted for use in NMR spectroscopy. The text covers a broad range of reagents that make it possible to determine the enantiomeric purity and assign the absolute configuration of many classes of compounds. Comprehensive in scope, the text describes the chiral NMR differentiating agents as derivatizing agents, solvating agents, metal-based reagents and liquid crystals and gels, and explains the range and types of compounds for which they can be used for analysis. New to this edition are the most recent findings in the field as well as the development of advanced NMR measurement techniques that allow for the simplification of complex spectra resulting in more readily identified enantiodifferentiation. This important resource: Includes the most recent coverage of a large range of compounds that can be analyzed using chiral NMR reagents Explores the use of chiral NMR reagents and explains their relationship to the stereochemistry of the analyzed molecules Offers the essential information needed to help decide which method is the best NMR method to apply to a class or molecules Contains experimental strategies for using the reagents that are likely to improve the quality of the results Differentiation of Chiral Compounds Using NMR Spectroscopy is a comprehensive guide designed for investigators planning to use NMR spectroscopy to determine enantiomeric purity or assign the absolute configuration of a compound.




Chiroptical Spectroscopy


Book Description

This book details chiroptical spectroscopic methods: electronic circular dichroism (ECD), optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and vibrational Raman optical activity (VROA). For each technique, the text presents experimental methods for measurements and theoretical methods for analyzing the experimental data. It also includes a set of experiments that can be adopted for undergraduate teaching laboratories. Each chapter is written in an easy-to-follow format for novice readers, with necessary theoretical formalism in appendices for advanced readers.




Discrimination of Chiral Compounds Using NMR Spectroscopy


Book Description

A comprehensive overview of the use of NMR spectroscopy for chiral discrimination Discrimination of Chiral Compounds Using NMR Spectroscopy concisely covers the broad array of reagents that make it possible to determine the optical purity and assign the absolute configuration of many classes of compounds. It describes chiral NMR derivatizing agents, solvating agents, metal-based reagents, and liquid crystals and discusses the range and types of compounds for which they can be used for analysis. After an overview of chiral reagents and methodologies, this reference: * Includes comprehensive coverage of the chiral reagents that have been reported * Catalogs the range of compounds for which different reagents have been shown to be effective * Includes specialty categories such as liquid crystals, ionic liquids, and the formation of chiral aggregates from achiral building blocks that do not fit into the broader categories * Offers experimental strategies for using the reagents that are likely to improve the quality of the results This guide describes the various systems and their overall utility, but goes further to show the full scope of the field as a way of guiding investigations into the optimal chiral reagents for use in NMR spectroscopy. It's a practical reference for organic chemists in the pharmaceutical industry, academia, and other areas, NMR spectroscopists, and researchers involved in the isolation and structure determination of natural products.




Chiral Analysis


Book Description

Chiral Analysis: Advances in Spectroscopy, Chromatography and Emerging Methods, Second Edition covers an important area of analytical chemistry of relevance to a wide variety of scientific professionals, including chemistry graduate students, analytical chemists, organic chemists, professionals in the pharmaceutical industry, and others with an interest in chirality and chiral analysis. This thoroughly revised second edition covers several new, important areas of chiral analysis that have emerged since the first edition. Three of the new methods provide higher sensitivity than can be realized with the current methods and are expected to become mainstream applications: cavity based methods offer vastly higher sensitivity than conventional polarimetric methods, microwave chiral detection provides unsurpassed sensitivity for identifying diastereomers, and the rotating electric field method offers a competing new approach for the separation of enantiomers. Another topic, chirality in extraterrestrial life, has not been discussed in any other book and is important for understanding the origin of life. - Offers the only book to cover both spectroscopic and separation methods in a single volume - Provides an up-to-date and detailed review of the various techniques available, including new techniques that have emerged since the first edition - Includes contributions from a range of leading experts in the field, now edited by award-winning chirality researcher Prasad Polavarapu




Differentiation of Enantiomers II


Book Description

Chiral Derivatizing Agents, Macrocycles, Metal Complexes and Liquid Crystals for Enantiomer Differentiation in NMR Spectroscopy: Thomas J. Wenzel. Chiral NMR Solvating Additives for Differentiation of Enantiomers: Gloria Uccello-Barretta and Federica Balzano. Chiral Sensor Devices for Differentiation of Enantiomers: Kyriaki Manoli, Maria Magliulo and Luisa Torsi. Enantiopure supramolecular cages: synthesis and chiral recognition properties: Thierry Brotin, Laure Guy, Alexandre Martinez, Jean-Pierre Dutasta. Interconversion of Stereochemically Labile Enantiomers (Enantiomerization) : Oliver Trapp. Anisotropy Spectra for Enantiomeric Differentiation of Biomolecular Building Blocks: A.C. Evans, C. Meinert, J.H. Bredehöft, C. Giri, N.C. Jones, S.V. Hoffmann, U.J. Meierhenrich. Self-disproportionation of Enantiomers of Enantiomerically Enriched Compounds: Alexander E. Sorochinsky and Vadim A. Soloshonok.




Stereoselective Synthesis of Drugs and Natural Products


Book Description

Brings together the best tested and proven stereoselective synthetic methods Both the chemical and pharmaceutical industries are increasingly dependent on stereoselective synthetic methods and strategies for the generation of new chiral drugs and natural products that offer specific 3-D structures. With the publication of Stereoselective Synthesis of Drugs and Natural Products, researchers can turn to this comprehensive two-volume work to guide them through all the core methods for the synthesis of chiral drugs and natural products. Stereoselective Synthesis of Drugs and Natural Products features contributions from an international team of synthetic chemists and pharmaceutical and natural product researchers. These authors have reviewed the tremendous body of literature in the field in order to compile a set of reliable, tested, and proven methods alongside step-by-step guidance. This practical resource not only explores synthetic methodology, but also reaction mechanisms and applications in medicinal chemistry and drug discovery. The publication begins with an introductory chapter covering general principles and methodologies, nomenclature, and strategies of stereoselective synthesis. Next, it is divided into three parts: Part One: General Methods and Strategies Part Two: Stereoselective Synthesis by Bond Formation including C-C bond formation C-H bond formation C-O bond formation C-N bond formation Other C-heteroatom formation and other bond formation Part Three: Methods of Analysis and Chiral Separation References in every chapter serve as a gateway to the literature in the field. With this publication as their guide, chemists involved in the stereoselective synthesis of drugs and natural products now have a single, expertly edited source for all the methods they need.




Chiral Separations and Stereochemical Elucidation


Book Description

An expert resource for chemists using stereochemical analysis methods In Chiral Separations and Stereochemical Elucidation: Fundamentals, Methods, and Applications, a team of distinguished researchers delivers a robust and authoritative discussion of the theoretical fundamentals of chiral separation, the most commonly used chiral selectors, and stereochemical elucidation methods. The book offers expert discussions of a variety of chiral separation methods by gas chromatography (GC), supercritical fluid chromatography (SFC), capillary electrophoresis (CE), and liquid chromatography (LC). The authors also describe several methods for stereochemical elucidation, including X-ray crystallography, nuclear magnetic resonance spectroscopy, and chiroptical methods. The explored material is ideal for practicing chemists seeking a resource to help them guide method development and optimization or to explain quality control-complements during target compound production. Readers will also find: A thorough introduction to the most important advances and applications in LC, GC, CE, SFC, and preparative chromatography Comprehensive explorations of the role of 2D-LC for chiral separation methods development and applications Practical discussions of the design, mechanisms, and applications of the most commonly used chiral selectors Fulsome treatments of the theoretical backgrounds, advantages, limitations, and applications of stereochemical elucidation methods Perfect for academic and industrial chemists specially in organic, analytical chemistry and pharmaceutical analysis. Chiral Separations and Stereochemical Elucidation: Fundamentals, Methods, and Applications will also benefit biochemists, environmental analysts, forensic and medicinal chemists as well as natural product chemists and those involved with stereochemistry or structural elucidation.




Encyclopedia of Spectroscopy and Spectrometry


Book Description

This third edition of the Encyclopedia of Spectroscopy and Spectrometry, Three Volume Set provides authoritative and comprehensive coverage of all aspects of spectroscopy and closely related subjects that use the same fundamental principles, including mass spectrometry, imaging techniques and applications. It includes the history, theoretical background, details of instrumentation and technology, and current applications of the key areas of spectroscopy. The new edition will include over 80 new articles across the field. These will complement those from the previous edition, which have been brought up-to-date to reflect the latest trends in the field. Coverage in the third edition includes: Atomic spectroscopy Electronic spectroscopy Fundamentals in spectroscopy High-Energy spectroscopy Magnetic resonance Mass spectrometry Spatially-resolved spectroscopic analysis Vibrational, rotational and Raman spectroscopies The new edition is aimed at professional scientists seeking to familiarize themselves with particular topics quickly and easily. This major reference work continues to be clear and accessible and focus on the fundamental principles, techniques and applications of spectroscopy and spectrometry. Incorporates more than 150 color figures, 5,000 references, and 300 articles for a thorough examination of the field Highlights new research and promotes innovation in applied areas ranging from food science and forensics to biomedicine and health Presents a one-stop resource for quick access to answers and an in-depth examination of topics in the spectroscopy and spectrometry arenas