Download or read book Frontiers in Iridium Catalyzed C H Borylation written by Matthew Alan Larsen and published by . This book was released on 2016 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following dissertation discusses the development of novel methodology for the catalytic borylation of C-H bonds and includes in-depth studies on the mechanism and selectivity of these synthetic transformations. These methods include the borylation of heteroaryl C-H bonds, the selective borylation of benzylic C-H bonds, and the directed and undirected borylation of unactivated alkyl C-H bonds. Chapter 1 contains a comprehensive review of C-H borylation methodology. This review focuses on the initial development of catalytic C-H borylation and on the state-of- the-art of methodology for the undirected and directed borylation of aryl, benzylic, and alkyl C-H bonds. Additionally, this review highlights knowledge gaps and unsolved challenges. Furthermore, this review provides the author's opinion on future directions for research on the borylation of C-H bonds. Chapter 2 describes the study of the iridium-catalyzed borylation of heteroaryl C- H bonds. Contained is an examination of the scope of the borylation of heterocycles containing more than one heteroatom and rules for predicting the site-selectivity of this reaction. Also included are experimental and computational studies that reveal the mechanism of this reaction and the origins of the observed regioselectivity. Chapter 3 discusses the development of the selective borylation of the primary benzylic C-H bonds of methylarenes. Key to this development was the discovery that the combination of a novel iridium catalyst and a silylborane allows for the selective borylation of benzylic C-H bonds over aryl C-H bonds. Experimental and computational studies that investigate the origins of this selectivity are also discussed. Chapter 4 discusses the development of the iridium-catalyzed, hydrosilyl-directed borylation of alkyl C-H bonds. This methodology allows for the diastereoselective borylation of secondary alkyl C-H bonds under relatively mild conditions. Chapter 5 explores the effect of ligand structure on the rates of alkyl C-H borylation catalyzed by Ir-phenanthroline complexes. Experimental and computational studies reveal that in addition to the relative electron-donating ability of phenanthrolines, weak interactions involving the phenanthroline in the transition state of the turnover- limiting step for the borylation of alkyl C-H bonds can have a large impact on the relative rates of alkyl C-H borylation catalyzed by various Ir-phenanthroline complexes.

Download or read book Advancing Frontiers in Reactive and Selective Iridium C h Borylation Catalysis and Targeted Silsesquioxane Synthesis written by Jonathan E. Dannatt and published by . This book was released on 2019 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies in this dissertation are aimed at uncovering reactive and selective Ir-catalyzed C-H borylation (CHB) catalysts. Due to the high versatility of organoboron species, green methodology to produce the C-B bond is poised to support a myriad of subsequent transformations. These transformations include Suzuki couplings, aminations, oxidations, halogenations, cyanations, and trifluoromethylations.Typical iridium catalyzed CHBs proceed through an iridium trisboryl with a bidentate ligand such as bipyridine or 1,10-phenanthroline. The selectivity of these standard catalysts is generally driven by sterics; however, many methods of overcoming the steric bias have been developed in the two decades since the first thermal catalytic C-H activation borylation. These methods include both inner- and outer-sphere directed mechanisms. Outer-sphere directed borylations have been accomplished by leveraging hydrogen bonding, Lewis acid-base, and ion-pairing as directing elements. In general this reactivity is activated by precise design of the bidentate ligand framework.Herein is reported a subtle electrostatic interaction to direct ortho-borylation of phenols by simply switching boron source from the common B2pin2 (pin = pinacolate) to B2eg2 (eg = ethyleneglycolate). This electrostatic interaction was revealed by a careful computational analysis of key C-H activation transition states. Understanding gained by the computational studies led to the redesign of the boron source which enabled by selectivities of > 99% ortho borylation. This methodology was extended to the highly selective ortho-borylation of anilines, and the underlying mechanism has been interrogated.Currently, iridium based catalysts have been generated to borylate ortho, meta, and even para to a variety of classes of substrates; however, control of selectivity can breakdown in many fluorinated arenes without a directing group. These substrates are challenging because the fluoro moiety being similar in size to a hydrogen offers little in the way of steric bias. While working to overcome these challenges, a serendipitously discovered hydrazone based ligand was discovered. Exploration of the catalysts generated by this ligand revealed not only impressive activity rivaling dtbpy but also incredible selectivity for meta to a fluoro group.In general iridium CHB catalysts selectively activate sp2 C-H bonds leaving all sp3 C-H bonds intact; however, a method to turn on sp3 C-H activation would be desirable. It was reasoned that a directing group able to increase the effective concentration of the iridium catalyst near a C(sp3)-H bond may enable this transformation. Indeed, it was discovered that catalysts able to accept amide directing groups were able to selectively borylate compounds with amide N-methyl substituents.

Download or read book Iridium Catalyzed C H Borylation written by Behnaz Ghaffari and published by . This book was released on 2016 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Iridium Catalyzed C H Activation borylation of Aromatic heteroaromatic Substrates and Its Application in Small Molecule Synthesis written by Venkata Apparao Kallepalli and published by . This book was released on 2010 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Part A written by Susanne L. Miller and published by . This book was released on 2017 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regioselective Iridium Catalyzed C H Activation borylation of 2 substituted Indoles written by Sulagna Paul and published by . This book was released on 2007 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Remote C H Bond Functionalizations written by Debabrata Maiti and published by John Wiley & Sons. This book was released on 2021-04-26 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide to contemporary advancements in the field of distal C-H functionalizations An important and dynamic topic within the modern field of organic synthesis, selective functionalization of C-H bonds can be used in a variety of applications across the pharmaceutical and agrochemical industries. Remote C-H Bond Functionalizations presents an inclusive account of the most recent developments and potential applications of performing variegated functionalizations selectively at the distal positions of organic compounds. Featuring contributions by an international team of experts, this authoritative volume provides deep insight into distal functionalizations, including detailed discussion of mechanisms, the engineering of templates, and the design of strategies. The text covers a diverse range of topics including C-H functionalization of palladium/norbornene catalysis, ruthenium-catalyzed remote functionalization, the non-directed distal C(sp2)-H, functionalization, transition metal catalyzed distal para-selective C-H functionalization, and much more. Reviewing contemporary advancements in the field while laying the foundation for future research, this important resource: Provides the most recent research and thorough coverage of the subject available in a single volume Offers practical information on C-H functionalizations in various industries Includes an up-to-date introduction to distal C-H functionalizations Remote C-H Bond Functionalizations is a must-read for every synthetic chemist, including chemists working with organometallics, organic chemists and researchers, and industrial chemists.

Download or read book Iridium Catalysis written by Pher G. Andersson and published by Springer Science & Business Media. This book was released on 2011-01-05 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the contents: Robert H Crabtree: Introduction and History. - Montserrat Diéguez, Oscar Pàmies and Carmen Claver: Iridium-catalysed hydrogenation using phosphorous ligands. - David H. Woodmansee and Andreas Pfaltz: Iridium Catalyzed Asymmetric Hydrogenation of Olefins with Chiral N,P and C,N Ligands. - Ourida Saidi and Jonathan M J Williams: Iridium-catalyzed Hydrogen Transfer Reactions. - John F. Bower and Michael J. Krische: Formation of C-C Bonds via Iridium Catalyzed Hydrogenation and Transfer Hydrogenation. - Jongwook Choi, Alan S. Goldman: Ir-Catalyzed Functionalization of CH Bonds. - Mark P. Pouy and John F. Hartwig: Iridium-Catalyzed Allylic Substitution. - Daniel Carmona and Luis A. Oro: Iridium-catalyzed 1.3-dipolar cycloadditions.

Download or read book Iridium Catalyzed Aromatic Borylation and Its Applications in One pot Preparations of Substituted Aromatic Building Blocks written by Ghayoor Abbas Chotana and published by . This book was released on 2009 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Studies of Iridium catalyzed Borylation Reactions and Defying Torquoselectivity in Cyclobutene Ring opening Via Strain induced Thermal Selectivity written by Aaron Gabriel Green and published by . This book was released on 2013 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies reported in this dissertation illustrate a few selected examples of using density functional theory (DFT) calculations to investigate various aspects of iridium-catalyzed reactions and ring-opening of bicyclic cyclobutene rings. These computational predictions not only reproduce and explain experimental results and offer insights to reaction mechanisms, but also provide theoretical models to predict reactivity, regio- and stereoselectivities. Chapter 1 is a review surveying the literature of iridium-catalyzed borylation reactions. Emphasis is placed on iridium-catalyzed borylation of alkenes and arenes. In particular, I discuss the history leading up to the current catalyst systems for iridium-catalyzed borylation reactions, and regioselectivity of borylation for a number of different substrates. Despite the large amount of work on iridium-catalyzed borylation reactions, this review shows that there is still much to be understood regarding the origins of observed regioselectivities. Chapters 2 and 3 describe theoretical investigations of Ir(III)-catalyzed borylation reactions. The origins of regioselectivities observed in the borylation of pyridine are discussed in Chapter 2. The high selectivity for borylation at the 3- and 4- position of pyridine is attributed to the formation of a Lewis acid-base complex between pyridine and either boron species or iridium species in solution. The origins of regioselectivities for the iridium-catalyzed borylation of substituted arenes and 5-membered heterocycles are discussed in Chapter 3. The distortion/interaction model was employed to understand the origins of the selectivities in these reactions. Computations revealed that regioselectivity is mainly controlled by differences in the interaction energies between the iridium catalyst and arene carbon. Chapter 4 illustrates a theoretical study of ring-opening in strained, trans-substituted cyclobutenes. The torquoselectively preferred outward ring-opening products are unable to form due to ring strain inherent in 9- and 10-membered macrocyclic (E, E)-1,3-dienes. As a result of this study, I propose a general methodology for stereoselective synthesis of macrocyclic (Z, Z)-1,3-dienes termed strain-induced thermal selectivity (SITS).

Download or read book Molecular Technology Volume 2 written by Hisashi Yamamoto and published by John Wiley & Sons. This book was released on 2018-12-10 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by foremost leaders in chemical research together with a number of distinguished international authors, Volume 2 presents the most important and promising recent chemical developments in life sciences, neatly summarized in one book. Interdisciplinary and application-oriented, this ready reference focuses on methods and processes with a high practical aspect, covering new trends in drug delivery, in-vivo analysis, structure formation and much more. Of great interest to chemists and life scientists in academia and industry.

Download or read book Phosphorus III Ligands in Homogeneous Catalysis written by Paul C. J. Kamer and published by John Wiley & Sons. This book was released on 2012-05-09 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last 60 years the increasing knowledge of transition metal chemistry has resulted in an enormous advance of homogeneous catalysis as an essential tool in both academic and industrial fields. Remarkably, phosphorus(III) donor ligands have played an important role in several of the acknowledged catalytic reactions. The positive effects of phosphine ligands in transition metal homogeneous catalysis have contributed largely to the evolution of the field into an indispensable tool in organic synthesis and the industrial production of chemicals. This book aims to address the design and synthesis of a comprehensive compilation of P(III) ligands for homogeneous catalysis. It not only focuses on the well-known traditional ligands that have been explored by catalysis researchers, but also includes promising ligand types that have traditionally been ignored mainly because of their challenging synthesis. Topics covered include ligand effects in homogeneous catalysis and rational catalyst design, P-stereogenic ligands, calixarenes, supramolecular approaches, solid phase synthesis, biological approaches, and solubility and separation. Ligand families covered in this book include phosphine, diphosphine, phosphite, diphosphite, phosphoramidite, phosphonite, phosphinite, phosphole, phosphinine, phosphinidenene, phosphaalkenes, phosphaalkynes, P-chiral ligands, and cage ligands. Each ligand class is accompanied by detailed and reliable synthetic procedures. Often the rate limiting step in the application of ligands in catalysis is the synthesis of the ligands themselves, which can often be very challenging and time consuming. This book will provide helpful advice as to the accessibility of ligands as well as their synthesis, thereby allowing researchers to make a more informed choice. Phosphorus(III) Ligands in Homogeneous Catalysis: Design and Synthesis is an essential overview of this important class of catalysts for academic and industrial researchers working in catalyst development, organometallic and synthetic chemistry.

Download or read book Organosilicon Chemistry written by Tamejiro Hiyama and published by John Wiley & Sons. This book was released on 2020-02-18 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a unique summary of important catalytic reactions in the presence of silicon A must-have for all synthetic chemists, this book summarizes all of the important developments in the application of organosilicon compounds in organic synthesis and catalysis. Edited by two world leaders in the field, it describes different approaches and covers a broad range of reactions, e.g. catalytic generation of silicon nucleophiles, Si-H Bond activation, C-H bond silylation, silicon-based cross-coupling reactions, and hydrosilylation in the presence of earth-abundant metals. In addition to the topics covered above, Organosilicon Chemistry: Novel Approaches and Reactions features chapters that look at Lewis base activation of silicon Lewis acids, silylenes as ligands in catalysis, and chiral silicon molecules. -The first book about this topic in decades, covering a broad range of reactions -Covers new approaches and novel catalyst systems that have been developed in recent years -Written by well-known, international experts in the areas of organometallic silicon chemistry and organosilicon cross-coupling reactions Organosilicon Chemistry: Novel Approaches and Reactions is an indispensable source of information for synthetic chemists in academia and industry, working in the field of organic synthesis, catalysis, and main-group chemistry.

Download or read book C H Bond Activation and Catalytic Functionalization I written by Pierre H. Dixneuf and published by Springer. This book was released on 2015-12-18 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics of pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors. All chapters from Topics in Organometallic Chemistry are published OnlineFirst with an individual DOI. In references, Topics in Organometallic Chemistry is abbreviated as Top Organomet Chem and cited as a journal.

Download or read book Organotransition Metal Chemistry From Bonding to Catalysis written by John F. Hartwig and published by . This book was released on 2010-02-10 with total page 1172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on Collman et al.'s best-selling classic book, Principles and Applications of Organotransition Metal Chemistry, Hartwig's text consists of new or thoroughly updated and restructured chapters and provides an in-depth view into mechanism, reaction scope, and applications. It covers the most important developments in the field over the last twenty years with great clarity with a selective, but thorough and authoritative coverage of the fundamentals of organometallic chemistry, the elementary reactions of these complexes, and many catalytic processes occurring through organometallic intermediates, making this the Organotransition Metal Chemistry text for a new generation of scientists.

Download or read book Synthesis and Application of Organoboron Compounds written by Elena Fernández and published by Springer. This book was released on 2015-03-04 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics in pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors.

Download or read book Functional Polymers by Post Polymerization Modification written by Patrick Theato and published by John Wiley & Sons. This book was released on 2013-02-12 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: In modern polymer science a variety of polymerization methods for the direct synthesis of polymers bearing functional groups are known. However, there is still a large number of functional groups that may either completely prevent polymerization or lead to side reactions. Post-polymerization modification, also known as polymer-analogous modification, is an alternative approach to overcome these limitations. It is based on the polymerization of monomers with functional groups that are inert towards the polymerization conditions but allow a quantitative conversion in a subsequent reaction step yielding a broad range of other functional groups. Thus, diverse libraries of functional polymers with identical average degrees of polymerization but variable side chain functionality may easily be generated. Filling the gap for a book dealing with synthetic strategies and recent developments, this volume provides a comprehensive and up-to-date overview of the field of post-polymerization modification. As such, the international team of expert authors covers a wide range of topics, including new synthetic techniques utilizing different reactive groups for post-polymerization modifications with examples ranging from modification of biomimetic and biological polymers to modification of surfaces. With its guidelines this is an indispensable and interdisciplinary reference for scientists working in both academic and industrial polymer research.