Recent Advances In Organocatalysis

Organocatalysis has recently attracted enormous attention as green and sustainable catalysis. It was realized as a fundamental field providing wide families of catalysts for important organic transformations. It will certainly develop in the future. Given the diversity of accessible transformations, metal-catalyzed reactions have become major tools in organic synthesis that will undoubtedly continue to have an important impact in the future. Alternatively, over the last years, a metal-free approach such as organocatalysis has reached a level of faithfulness, allowing researchers to discover new catalytic systems based on engagement of new or early-prepared organic molecules as organocatalysts. Organocatalysis meets green chemistry principles, especially the reduction of toxicity and chemical accidents, the biodegradability, and the use of benign and friendlier reaction media and conditions.

Asymmetric Organocatalysis Comprehensive resource on the latest and most important developments in the highly vivid field of asymmetric organocatalysis The book provides a comprehensive overview of the most important advancements in the field of asymmetric organocatalysis that have occurred within the last decade. It presents valuable examples of newly developed synthetic methodologies based on various organocatalytic activation modes. Special emphasis is given to strategies where organocatalysis is expanding its potential by pushing the boundaries and founding new synergistic interactions with other fields of synthetic chemistry, such as metal catalysis, photocatalysis, and biocatalysis. The application of different concepts (such as vinylogy, dearomatization, or cascade reactivity), resulting in the development of new functionalization strategies, is also discussed. Sample topics covered within the book include: New developments in enantioselective Brønsted acid catalysis with strong hydrogen-bond donors Asymmetric phase-transfer catalysis, from classical applications to new concepts Halogen-bonding organocatalysis Asymmetric electrochemical organocatalysis and synergistic organo-organocatalysis Immobilized organocatalysts for enantioselective continuous flow processes Mechanochemistry and high-pressure techniques in asymmetric organocatalysis Useful tools in elucidation of organocatalytic reaction mechanisms With an overall focus on new reactions and catalysts, this two-volume work is an indispensable source for everyone working in the field of asymmetric organocatalysis.

Organocatalysis are an important tool for greener catalytic processes due to the lack of precious metals used. This book explores different organocatalysts and their use in synthesis. Topics covered include zwitterionic imidazolium salt catalysts, asymmetric catalysts in aqueous media, beaker yeast catalysis, organocatalysts for Aldol and Michael reactions, amino acid-based organocatalysts, and Brönsted acidic surfactant organocatalysts.

This book provides an excellent overview on state-of-the-art of modern organocatalysis. It presents the contributions from leading experts, with backgrounds in academia and industry, to an Ernst Schering Research Foundation Symposium held in April 2007. It will be of interest to those who want a general overview of the topic, but also to those who want to learn more about the state-of-the-art, current trends and perspectives in this highly dynamic field of research.

Organocatalysis is considered today one of the three pillars in asymmetric catalysis, along with biocatalysis and organometallic catalysis. The possibility to combine organocatalysis with radical chemistry, photocatalysis and enabling technologies opened new avenues in organic synthesis.

The Series is intended to provide an accessible reference for postgraduates and industrialists working in the field of catalysis and its applications. Books will be produced either as monographs or reference handbooks. The Series will cover research developments and applications of catalysis, in both academia and industry. --Résumé de l'éditeur.

In this reference leaders at the forefront of research provide an insight into one of the hottest topics in organic synthesis, focusing on the most important enantioselective reactions. Clearly structured, each entry begins with a concise introduction, including a mechanistic discussion of the reaction, followed by preparative guidelines for newcomers, such as carefully selected working procedures with critical notes for bench chemists, rules of thumb and tips and tricks.

Chiral spirolactones, including spiropropyllactones, spirobutyrolactones, and spirovalerolactones, are important heterocyclic frameworks that attracted the attention of organic and medicinal chemists because these motifs constitute the core structure of several natural products and bioactive molecules. The absolute configuration and the substituents on the fully substituted spirocyclic stereocenter of the lactone can potentially enhance specificity for ligand-protein binding and enhance bioavailability, potency, and metabolic stability. So, intensive attention from chemists has been paid to the synthetic methods leading to such prominent structural motifs. The synthetic methods can be divided into two main classes. The first approach takes advantage of the presence of the existing lactone structure and focuses on its functionalization. The second approach is the lactone framework constructed from various precursors in a direct spirolactonization reaction. In this review, for convenience in reading, the recent advances in the synthesis of spirolactones are summarized and discussed according to the two major organocatalytic asymmetric synthetic routes: (i) using the lactone-related frameworks as building blocks; and (ii) direct spirolactonization reaction using various reagents. This review also describes both the mechanisms and related transformations, and gives some insights into challenging issues in this research field, which will enlighten the future development of this field.

Considering the challenge of sustainability facing our society in the coming decades, catalysis is without any doubt a research area of major importance. In this regard, asymmetric organocatalysis, now considered a pillar of green chemistry, deserves particular attention. The first chapter of this volume examines the topic of asymmetric organocatalysis in light of radical chemistry. Recent important progress in this field has been attained by promoting the formation and harnessing the high reactivity of open-shell intermediates. Merging organocatalysis with radical chemistry has been the key to solving some longstanding bottlenecks, and has also significantly contributed to reinforcing the key role of organocatalysis in asymmetric catalysis. This chapter presents the most significant developments in this area, with a particular focus on asymmetric SOMO- and photoredox-organocatalyzed transformations. Chapter 2 focuses on quaternary ammonium salts (R4N+X-), especially chiral derivatives, and their behavior as unique catalysts in organocatalysis. Forming chiral ion-pairs capable of promoting asymmetric reactions, they also operate as unique “transporters involved in phase transfer catalytic processes between liquid–liquid or liquid–solid systems. Furthermore, they offer unique opportunities when forming cooperative ion-paired entities R4N+X-, allowing a synergistic implication of the counter-ion X- either as Brønsted bases or Lewis bases. Specific design of such chiral catalysts in modern chemistry and better insight into their mode of activation facilitates efficient and unprecedented chemical transformations. This chapter provides an overview of the use of chiral quaternary ammonium salts in organocatalysis, emphasizing both general mechanistic aspects and the scope of this approach. Presents the most significant developments with a particular focus on asymmetric SOMO- and photoredox-organocatalyzed transformations Givies a larger overview of chiral ammonium salts in organocatalysis rather than a specific review dedicated to specialists in this area Affords a historical evolution of this field of research

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.The chapter "Enamine/Transition Metal Combined Catalysis: Catalytic Transformations Involving Organometallic Electrophilic Intermediates" is available open access under a CC BY 4.0 License via link.springer.com.