Download or read book Synthetic Applications of Iridium catalyzed Aromatic C H Borylation written by Feng Shi and published by . This book was released on 2007 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Iridium Catalyzed C H Borylation written by Kristin Anne Gore and published by . This book was released on 2017 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 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 Catalysts for Organic Reactions written by Luis A. Oro and published by Springer Nature. This book was released on 2021-03-29 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new volume “Iridium Catalysts for Organic Reactions” in the series “Topics in Organometallic Chemistry” intends to update several representative well-known reactions and to introduce other less known or new reactions in particular covering sustainability aspects. Iridium complexes are efficient in many catalytic homogeneous transformations providing high efficiency in both results, activity and selectivity. The interest of the book lies in the presentation of the advances, new perspectives and application in a variety of representative iridium-catalysed reaction. All chapters in the volume are contributed by relevant international experts in the field. The book is aimed at researchers, graduate students and synthetic chemists at all levels in academia and industry.

Download or read book Iridium Complexes in Organic Synthesis written by Luis A. Oro and published by John Wiley & Sons. This book was released on 2008-12-03 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ranging from hydrogenation to hydroamination, cycloadditions and nanoparticles, this first handbook to comprehensively cover the topic of iridium in synthesis discusses the important advances in iridium-catalyzed reactions, namely the use of iridium complexes in enantioselective catalysis. A must for organic, complex and catalytic chemists, as well as those working with/on organometallics.

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 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 catalyzed Borylation of Aromatic and Aliphatic C H Bonds Methodology and Mechanism written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selective Synthesis of Aromatic and Saturated Organoboron Compounds written by Timothy Michael Shannon and published by . This book was released on 2019 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: C-H borylation (CHB) is a method to functionalize C-H bonds. The development of CHB has taken many years but is getting to the point of well-established chemistry. The directed CHB is possible for a variety of differing substrates and differing loctions of direction. A new method for ortho directed CHB of esters amides and ketones was developed through the use of pyridine based monodentate ligands.Using 4-cyano-2-methoxypyridine as a ligand iridium catalyzed CHB of esters ketones and amides were performed. The mechanism of CHB in this process likely operates through a different rate-determining step than the other C-H borylation methods used as it was found that the kinetic isotope effect data did not clearly support C-H activation as rate-determining.The development of sp3 C-H borylation is not as advanced as sp2 CHB; a 2-step process to generate the same products could be equally desirable. Utilizing a borylation-hydrogenation process the selectivity that have already been developed for sp2 C-H borylation can be used to generate the sp3 carbon boron bond at the desired location. This process has been developed and limitations of it have been investigated.

Download or read book Developing and Understanding Iridium catalysed Arene Borylation written by Peter Harrisson and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Iridium catalysed C-H borylation has moved from an interesting observation to an efficient catalytic reaction. This work has developed and improved upon some of the key issues associated with the methodology. The one-pot conversion of aryl boronates, generated by C-H borylation, to other functionality has been one area of interest. However, reactions typically require a change in reaction solvent to make this possible. This thesis describes a one-pot, single solvent C-H borylation/Suzuki-Miyaura cross-coupling sequence. The key to this transformation is the use of methyl tert-butyl ether (MTBE). This procedure allows efficient synthesis of biaryls by initial C-H borylation of aromatic substrates followed by addition of water, subsequent reagents and aryl halide to complete the Suzuki-Miyaura cross-coupling without the need for change in reaction solvent. Another issue associated with the C-H borylation reaction is the extended reaction times required for some substrates. This issue was tackled by development of a microwave accelerated C-H borylation reaction. Microwave reactions are conducted at the same temperature as standard heated reactions with accelerations of 2 - 24 times affording comparable product yields. Typically reaction times were reduced from hours to minutes. A microwave accelerated one-pot, single solvent C-H borylation/Suzuki-Miyaura cross-coupling sequence allowed synthesis of biaryls from arene plus aryl halides in reaction times of minutes. Subsequent work focussed on the borylation of novel substrates classes, in particular quinolines. The borylation of substituted quinolines highlighted interesting electronic selectivity of the reaction. The site of borylation can be directed by changing the nature of the substituent on the ring. DFT calculations have been conducted to gain understanding into the causes of selectivity. A link between C-H acidity, calculated by DFT methods, and the borylation site was observed. Preliminary studies into the borylation of azaindoles are discussed. Studies towards a procedure to convert aryl boronates to trifluoromethyl groups are also been introduced.

Download or read book Advances in Cross Coupling Reactions written by José Pérez Sestelo and published by MDPI. This book was released on 2020-12-03 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this Special Issue, recent advances in cross-coupling reactions are presented in the form of original research articles, reviews, and short communications. These contributions cover different topics in this area, including novel coupling reactions, reaction conditions, synthetic alternatives, metal ligands, and applications for new pharmaceutical compounds and organic materials. In particular, the reviews deal with methodologies such as the synthesis of diarylketones through palladium catalysis and the most relevant examples of Suzuki–Miyaura and Buchwald–Hartwig coupling reactions in the synthesis of bioactive compounds. The synthetic utility of cross-coupling reactions for the synthesis of medium-size rings and the utility of Stille and Suzuki coupling reactions for the synthesis of new molecular machines based on sterically hindered anthracenyl trypticenyl units are also summarized. The original research articles present the synthesis of 2-alkynylpyrrols by inverse Sonogashira coupling and the synthesis of indoles under oxidative dearomative cross-dehydrogenative conditions. The efficient combination of iridium-catalyzed C–H borylation of aryl halides with the Sonogashira coupling and a sequential iridium-catalyzed borylation of NH-free pyrroles followed by a Suzuki–Miyaura reaction are included. The synthesis of aryl propionic acids, a common structural motif in medicinal chemistry, and the synthesis of new organic dyes are also covered.

Download or read book Borane Reagents written by Andrew Pelter and published by . This book was released on 1988 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Overcoming Regioselectivity Challenges in Iridium Catalyzed C h Borylation Via Noncovalent Interactions and Advances on Cross Coupling Reactions of Aryl Imidazolylsulfonates written by Jose Raul Montero Bastidas and published by . This book was released on 2021 with total page 879 pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct functionalization of C0́2H bonds reduces the number of synthetic steps for a target molecule enhancing efficiency and avoiding undesired waste material. Iridium catalyzed C-H activation-borylation (CHB) is an established method to access aryl boronic esters. Regioselectivity challenges can arise when multiple hydrogens are present in the molecule. This thesis describes the design of novel strategies to selective direct the CHB to one specific position.Ortho selective CHB has the challenge to go against the traditional CHB selectivity dictated by steric effects. Previously, our group reported a strategy for highly ortho-selective CHB of anilines by using a small B2eg2 (eg = ethanediol) as the borylating reagent. However, the products were unstable and transesterification with pinacol was needed. Chapter 2 builds upon this issue and presents a solution based on the modulation of the size of the boron partner. Small diboron partners retain the high ortho regioselectivity for CHB of aniline but larger borylating reagents generate more stable products. In our estimation, B2bg2 (bg = 1,2-butanediol) represents the best balance of reactivity, regioselectivity and stability.Remote functionalization including para selective reactions are difficult because a potential directing group would be far from the desired reactive site. Chapter 3 details how para CHB of tetraalkylammonium sulfates and sulfamates have been achieved using bipyridine-ligated Ir boryl catalysts. Selectivities can be modulated by both the length of the alkyl groups in the tetraalkylammonium cations and the substituents on the bipyridine ligands. Ion pairing, where the alkyl groups of the cation shield the meta C8́2H bonds in the counteranions, is proposed to account for para selectivity. The 4,4'-dimethoxy-2,2'-bipyridine ligand gave superior selectivities.The next chapter describes how intramolecular hydrogen bonding (IMHB) can lead to steric shielding effects that can direct CHB regiochemistry. Bpin/arene IMHB can promote remote borylations of N-borylated anilines, 2-amino-N-alkylpyridine, tetrahydroquinolines, indoles and 1-borylated naphthalenes. Our studies support molecular geometries with the Bpin orientation controlled by a C-H0́Ø0́Ø0́ØO IMHB. Calculated rotation barriers to displace the Bpin group are above 4 kcal/mol, suggesting that the planar ground conformation of the borylated arenes is retained during CHB. This study informs researchers to evaluate not only inter- but also intramolecular noncovalent interactions as potential drivers of remote CHB regioselectivity.The borylated products from CHB can be further manipulated in Suzuki-Miyaura cross-coupling (SMC) with aryl halides as the typical electrophilic partner. Aryl imidazolylsulfonates are nongenotoxic electrophiles that can be used in palladium catalyzed SMC to avoid halogenated materials. Chapter 5 shows the efforts towards a nickel-catalyzed SMC of aryl imidazolyl-sulfonates. Results show considerable amounts of the corresponding diarylsulfate formed during the reaction. Interestingly, the diaryl sulfa byproducts were found to be competent electrophilic partners for both palladium and nickel-catalyzed SMC.In summary, this thesis presents novel methodologies to access challenging transformations as the para borylations of phenols, anilines and benzyl alcohols. This was possible by the analysis of the different components of the catalytic system: design of ligands, diboron partners and substrate directing groups and how they interact during the reaction. Finally, the potential of aryl imidazolylsulfonates as nongenotoxic pseudohalides in nickel-catalyzed SMC was evaluated.

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 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.