Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Development of New Synthetic Approaches to Access Functionalized Carbocycles and Heterocycles by Transition Metal Catalysis
Synthesizing Annulated Carbocycles and Heterocycles
Author: S. ThavaselvanPublisher:
ISBN: 9781805292470
Category :
Languages : en
Pages : 0
Book Description
S. Thavaselvan is a renowned scientist in the field of organic chemistry, particularly in the area of synthesizing annulated carbocycles and heterocycles. In this area of research, he has made significant contributions to the development of new methodologies for the synthesis of complex molecules with diverse biological activities. Synthesis of annulated carbocycles and heterocycles is a challenging task due to the presence of multiple functional groups and the complexity of the reaction pathways involved. However, with the development of new methods and strategies, this area of research has seen rapid growth in recent years. Cyclization reactions, which involve the formation of a ring from a linear precursor, are the most common methods used for the synthesis of annulated carbocycles and heterocycles. These reactions can be catalyzed by a variety of transition metals such as palladium, rhodium, ruthenium, nickel, copper, and iron. The choice of metal catalyst and ligand can significantly influence the outcome of the reaction, particularly with respect to stereoselectivity and regioselectivity. Chiral ligands are used to achieve asymmetric synthesis of annulated carbocycles and heterocycles, while non-chiral ligands are used for stereoselective synthesis. Aromatic and aliphatic compounds can be used as starting materials for the synthesis of these complex molecules, and a range of functional groups including nitrogen, oxygen, and sulfur can be incorporated into the final product. The synthesis of annulated carbocycles and heterocycles can also involve nucleophilic substitution, electrophilic substitution, cross-coupling reactions, ring opening reactions, rearrangement, reduction, and oxidation. Grignard reagents, Sonogashira reaction, Suzuki reaction, and Heck reaction are some of the most commonly used reactions for the synthesis of these compounds. Heteroaromatic compounds such as pyridine, indole, quinoline, pyrimidine, pyrazine, benzofuran, benzothiophene, benzimidazole, isoquinoline, and pyrrole are commonly used as building blocks for the synthesis of annulated carbocycles and heterocycles due to their diverse biological activities. In conclusion, S. Thavaselvan's research in the area of synthesizing annulated carbocycles and heterocycles has contributed significantly to the development of new methodologies for the synthesis of complex molecules with diverse biological activities. The use of different metal catalysts, ligands, and functional groups has enabled the development of efficient and selective synthetic methods for the preparation of these complex molecules.
Heterocycles from Transition Metal Catalysis
Author: András KotschyPublisher: Springer Science & Business Media
ISBN: 9781402036248
Category : Science
Languages : en
Pages : 224
Book Description
"Heterocycles from Transition Metal Catalysis: Formation and Functionalization" provides a concise summary of the prominent role of late transition metal (palladium, nickel, copper) catalysed processes in the synthesis and functionalization of heterocyclic systems. It gives an introduction to catalytic transformations, an overview of the most important reaction types, and presents synthetically useful catalytic processes classified by the target system and the type of transformation. The book provides a representative selection of transition metal catalysed reactions transformations that are relevant in heterocyclic chemistry. In this way, the authors present a useful resource for members of the academic community looking for a textbook as well as industrial chemists in search of a reference book. This book will be an invaluable resource for synthetic chemists, medicinal chemists, and those more generally interested in applied catalysis.
New Transition Metal-catalyzed Synthesis and Functionalization of Heterocycles and Carbocycles
Author: Chandi Charan MalakarPublisher:
ISBN:
Category :
Languages : en
Pages : 30
Book Description
Heterocycles from Double-Functionalized Arenes
Author: Xiao-Feng WuPublisher: Royal Society of Chemistry
ISBN: 1782621369
Category : Science
Languages : en
Pages : 315
Book Description
An introduction to transition metal catalyzed coupling reactions of double-functionalized arenes in heterocycle synthesis.
Advances in Transition-Metal Mediated Heterocyclic Synthesis
Author: Daniel SolePublisher: Academic Press
ISBN: 0128116528
Category : Science
Languages : en
Pages : 368
Book Description
Advances in Transition-Metal Mediated Heterocyclic Synthesis provides an overview of recent catalytic reactions involving transition metals to produce heterocyclic compounds. The book is organized according to the type of transformation used to achieve the synthesis of the heterocyclic systems (mainly aza- and oxa-heterocycles). As such, it covers recent applications on the synthesis of heterocycles, also describing the details of the novel transformations in a didactic manner to motivate readers in search of new catalytic processes. The editors have included state-of-the-art strategies, including transition-metal reactions involving unsaturated systems (reactions of allenes, new gold(I)-catalyzed reactions, and Prins reaction). Chapters highlight the versatility of organopalladium chemistry dealing with carbonylative transformations, C-H activation reactions, coupling processes, and the control of the ambiphilic character of organopalladium species. Finally, the book discusses new reactions leading to heterocycles based on C-H activation processes catalyzed by other metals (Rh, Ru, Co). Written by an outstanding team of authors who are leading experts in organometallic chemistry and organic synthesis, this book is a valuable resource not only for chemists mainly focused on synthesis, but also for those interested in reaction mechanisms involving transition metals. Helpfully organized by transformation type to stimulate the search for new synthetic processes Completely illustrated and written by global experts Includes thoughtfully selected strategies chosen by the editors to exemplify the state-of-the-art of the subject, including transition-metal reactions involving unsaturated systems, organopalladium chemistry, and metal-catalyzed C-H activation
Transition Metal-catalyzed Preparation and Functionalization of Nitrogen-containing Heterocycles
Author: Malcolm P. HuestisPublisher:
ISBN:
Category : University of Ottawa theses
Languages : en
Pages : 148
Book Description
Metals and Non-metals
Author: Navjeet KaurPublisher: CRC Press
ISBN: 1000733416
Category : Science
Languages : en
Pages : 404
Book Description
Design of new processes that avoid the use of toxic reagents has been the focus of intense research of late. Catalysis by metals and non-metals offers diverse opportunities for the development of new organic reactions with promising range of selectivities—chemoselectivity, regioselectivity, diastereoselectivity, and enantioselectivity. Furthermore, these transformations frequently occur under mild conditions, tolerate a broad array of functional groups, and proceed with high stereoselectivity. The area of catalysis is sometimes referred to as a ‘foundational pillar’ of green chemistry. Catalytic reactions often reduce energy requirements and decrease separations because of increased selectivity; they are also capable of permitting the use of renewable feedstocks of less toxic reagents or minimizing the quantities of reagents needed. New catalytic organic synthesis methodologies have, thus, offered several possibilities for considerable improvement in the eco-compatibility of fine chemical production. Hence, these catalytic methodologies have emerged as powerful tools for the efficient and chemoselective synthesis of heterocyclic molecules. Key Features: Presents the synthesis of different five-membered heterocycles. Contains the most up-to-date information in this fast-moving field. Covers novel catalytic approaches used in the study and application of catalysts in synthetic organic reactions. Presents new methodologies for the synthesis of heterocycles.
A Mechanistic Approach Towards the Discovery of Catalytic Acylation Reactions
Author: Wanying ZhangPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The development of new, efficient methods for the formation of carbon-carbon bonds using transition metal catalysis has broad applications in the field of organic chemistry and is the key to efficient chemical synthesis. Many efforts had been made to develop efficient ways to make these linkages particularly with the aid of metals such as Rh, Pd, Ni, Ru and Cu. Our group is primarily focused on exploring how these transition metals can activate typically inert functional groups, paving way to new synthetic routes to construct more complex molecules. Chapter 1 describes attempts that were conducted to achieve hydroacylation between an aldehyde and a non-conjugated alkene via a metal hydride intermediate. The use of RuHCl(CO)(PPh3)3 proved to be the most efficient catalyst for this transformation thus far. Mechanistic investigations were conducted to explore different possibilities to enable this transformation. This chapter also identifies a new self-aldol domino reaction, which consists of a self-aldol condensation of an aldehyde, followed by oxidation and decarbonylation giving rise to a ketone product. Finally, the use of a simple and direct method to access deuterated aldehydes using RuHCl(CO)(PPh3)3 as a catalyst and D2O as a deuterium source is outlined. Chapter 2 describes a novel Suzuki-Miyaura system that couples esters and boronic esters to form the corresponding ketone product. It was found that an NHC-based Pd catalyst is crucial in the transformation wherein it activates the C(acyl)-O bond of the ester. It is notable that this transformation takes place with the absence of decarbonylation. Reactivity under water in the presence of surfactants was also discovered. Results in aqueous media were demonstrated to be milder than in organic conditions, while achieving similar yields. This system was also applied to coupling of esters and anilines.
Transition Metal Catalysis for Organic Synthesis
Author: Stephen SpinellaPublisher:
ISBN:
Category : Organic compounds
Languages : en
Pages : 57
Book Description
Transition metal-catalyzed reactions are one of the most powerful and direct approaches for the synthesis of organic molecules. During the past several decades, phosphorus containing ligands have been extensively used in transition metal catalyzed C-C and C-H bond forming reactions. Development of new phosphine ligands for palladium cross coupling and also methodology for C-H activation strategies will be the focus of this dissertation. A variety of triazole containing monophosphine ligands have been prepared via efficient 1,3-dipolar cycloaddition of readily available azides and acetylenes. Their palladium complexes provided excellent yields in the amination reactions (up to 98% yield) and Suzuki-Miyaura coupling reactions (up to 99% yield) of unactivated aryl chlorides. A CAChe model for one of the Pd-complexes shows that the likelihood of a Pd-arene interaction might be a rationale for its high catalytic reactivity. A main goal for Organic chemists is to develop and utilize efficient and atom-economical methods for the elaboration of complex structures from simple and readily available starting materials. C-H bonds are the most fundamental linkage in organic chemistry and recently tremendous strides have been have been made in the functionalization of C-H bonds. A central goal in the development of any new methodology is synthetic utility, which has been difficult to achieve with C-H activation strategies because of the inherent stability of C-H bond. Aryl carboxylic acid derivatives are very prevalent in industrial and pharmaceuticals and thus a direct C-H activation approach would be very desirable. A general protocol for the rhodium-catalyzed oxidative carbonylation of arenes to form esters has been developed. A broad substrate scope has been demonstrated allowing carbonylation of electron rich, electron-poor, and heterocyclic arenes, and the reaction shows wide functional group tolerance and excellent regioselectivities. Up to 96% yield of ortho-substituted aryl or heteroaryl carboxylic esters were obtained with this methodology. The possible mechanism for the rhodium-catalyzed oxidative carbonylation reaction was proposed in this article. Studies show that Oxone play an important role in the transformation. We have developed a new C2-symmetric monophosphine ligand based upon a C3* tunephos backbone. The ligand was available in several steps from commercially available starting materials. In future studies this ligand was be tested for its use in chiral cross coupling reactions.