Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Transition Metal Catalyzed C C Bond Formation Under Transfer Hydrogenation Conditions
Download Transition Metal Catalyzed C C Bond Formation Under Transfer Hydrogenation Conditions full books in PDF, epub, and Kindle. Read online Transition Metal Catalyzed C C Bond Formation Under Transfer Hydrogenation Conditions ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Transition Metal Catalyzed C-C Bond Formation Under Transfer Hydrogenation Conditions by : Joyce Chi Ching Leung
Download or read book Transition Metal Catalyzed C-C Bond Formation Under Transfer Hydrogenation Conditions written by Joyce Chi Ching Leung and published by . This book was released on 2013 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-carbon bond forming reactions are fundamental transformations for constructing structurally complex organic building blocks, especially in the realm of natural products synthesis. Classical protocols for forming a C-C bond typically require the use of stoichiometrically preformed organometallic reagents, constituting a major drawback for organic synthesis on process scale. Since the emergence of transition metal catalysis in hydrogenation and hydrogenative C-C coupling reactions, atom and step economy have become important considerations in the development of sustainable methods. In the Krische laboratory, our goal is to utilize abundant, renewable feedstocks, so that the reactions can proceed in an efficient and atom-economical manner. Our research focuses on developing new C-C bond forming protocols that transcend the use of stoichiometric, preformed organometallic reagents, in which [pi]-unsaturates can be employed as surrogates to discrete premetallated reagents. Under transition metal catalyzed transfer hydrogenation conditions, alcohols can engage in C-C coupling, avoiding unnecessary redox manipulations prior to carbonyl addition. Stereoselective variants of these reactions are also under extensive investigation to effect stereo-induction by way of chiral motifs found in ligands and counterions. The research presented in this dissertation represents the development of a new class of C-C bond forming transformations useful for constructing synthetic challenging molecules. Development of transfer hydrogenative C-C bond forming reactions in the form of carbonyl additions such as carbonyl allylation, carbonyl propargylation, carbonyl vinylation etc. are discussed in detail. Additionally, these methods avoid the use of stoichiometric chiral allenylmetal, propargylmetal or vinylmetal reagents, respectively, accessing diastereo- and enantioenriched products of carbonyl additions in the absence of stoichiometric organometallic byproducts. By exploiting the atom-economical transfer hydrogenative carbonyl addition protocols using ruthenium and iridium, preparations of important structural motifs that are abundant in natural products, such as allylic alcohols, homoallylic alcohols and homopropargylic alcohols, become more feasible and accessible.
Book Synopsis Transition Metal-catalyzed Reductive C-C Bond Formation Under Hydrogenation and Transfer Hydrogenation Conditions by : Ming-yu Ngai
Download or read book Transition Metal-catalyzed Reductive C-C Bond Formation Under Hydrogenation and Transfer Hydrogenation Conditions written by Ming-yu Ngai and published by . This book was released on 2008 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-carbon bond forming reactions are vital to the synthesis of natural products and pharmaceuticals. In 2003, the 200 best selling prescription drugs reported in Med Ad News are all organic compounds. Synthesizing these compounds involves many carbon-carbon bond forming processes, which are not trivial and typically generate large amounts of waste byproducts. Thus, development of an atom economical and environmentally benign carbon-carbon bond forming methodology is highly desirable. Hydrogenation is one of the most powerful catalytic reactions and has been utilized extensively in industry. Although carbon-carbon bond forming reactions under hydrogenation conditions, such as, alkene hydroformylation and the Fischer-Tropsch reaction are known, they are limited to the coupling of unsaturated hydrocarbons to carbon monoxide. Recently, a breakthrough was made by the Krische group, who demonstrated that catalytic hydrogenative C-C bond forming reactions can be extended to the coupling partners other than carbon monoxide. This discovery has led to the development of a new class of carbon-carbon bond forming reactions. Herein, an overview of transition metal-catalyzed reductive couplings of [pi]-unsaturated systems employing various external reductants is summarized in Chapter 1. Chapters 2-4 describe a series of rhodium- and iridium-catalyzed asymmetric hydrogenative couplings of various alkynes to a wide range of imines and carbonyl compounds. These byproduct-free transformations provide a variety of optically enriched allylic amines and allylic alcohols, which are found in numerous natural products, and are used as versatile precursors for the synthesis of many biologically active compounds. Transfer hydrogenation represents another important class of reactions in organic chemistry. This process employs hydrogen sources other than gaseous dihydrogen, such as isopropanol. The Krische group succeeded in developing a new family of transfer hydrogenative carbon-carbon bond formation reactions. Chapter 5 presents two novel ruthenium- and iridium-catalyzed transfer hydrogenative carbonyl allylation reactions. The catalytic system employing iridium complexes enables highly enantioselective carbonyl allylation from both the alcohol and aldehyde oxidation level. These systems define a departure from the use of preformed organometallic reagents in carbonyl additions that transcends the boundaries of oxidation level.
Book Synopsis Transition Metal Catalyzed Carbonyl Additions Under the Conditions of Transfer Hydrogenation by : Ryan Lloyd Patman
Download or read book Transition Metal Catalyzed Carbonyl Additions Under the Conditions of Transfer Hydrogenation written by Ryan Lloyd Patman and published by . This book was released on 2011 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficient construction of complex organic molecules mandates that an assortment of methods for forming C-C bonds be available to the practicing synthetic chemist. The addition of carbon based nucleophiles to carbonyl compounds represents a broad class of reactions used to achieve this goal. Traditional methodology requires the use of stoichiometrically preformed organometallic reagents as nucleophiles in this type of reaction. However, due to the moisture sensitivity, excessive preactivation and inevitable generation of stoichiometric waste required for the use of these reagents, alternative methods have become a focus of the synthetic organic community. The research presented in this dissertation describes a new class of C-C bond forming reactions enabled through catalytic transfer hydrogenation. Here, the development and implementation of efficient green methods for carbonyl addition employing [pi]-unsaturates as surrogates to preformed organometallic reagents is described. Additionally, this research describes the first systematic studies toward using alcohols as electrophiles in carbonyl allylation, propargylation and vinylation reactions.
Book Synopsis Transition Metal Catalyzed C-C Bond Formation Via Transfer Hydrogenation by : Hiroki Sato (Ph. D. in chemistry)
Download or read book Transition Metal Catalyzed C-C Bond Formation Via Transfer Hydrogenation written by Hiroki Sato (Ph. D. in chemistry) and published by . This book was released on 2018 with total page 1616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Transition Metal-catalyzed Carbon-carbon Bond Formation Utilizing Transfer Hydrogenation by : Timothy Patrick Montgomery
Download or read book Transition Metal-catalyzed Carbon-carbon Bond Formation Utilizing Transfer Hydrogenation written by Timothy Patrick Montgomery and published by . This book was released on 2015 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt: A central tenant of organic synthesis is the construction of carbon-carbon bonds. One of the traditional methods for carrying out such transformations is that of carbonyl addition. Unfortunately, traditional carbonyl addition chemistry suffers various drawbacks: preactivation, moisture sensitivity, and the generation of stoichiometric organometallic waste. The research presented in this dissertation focuses on the development of methods that make use of nucleophile-electrophile pairs generated in situ via transfer hydrogenation, which allow the formation of carbonyl or imine addition products from the alcohol or amine oxidation level; streamlining the construction of complex molecules from simple, readily available starting materials. Additionally, studies toward the total synthesis of the fibrinogen receptor inhibitor tetrafibricin, utilizing the methods developed in catalytic carbon-carbon bond formation through the addition, transfer or removal of hydrogen, are presented.
Book Synopsis Development of New Transition Metal Catalyzed C-C Bond Forming Reactions and Their Application Toward Natural Product Synthesis by : Abbas Hassan
Download or read book Development of New Transition Metal Catalyzed C-C Bond Forming Reactions and Their Application Toward Natural Product Synthesis written by Abbas Hassan and published by . This book was released on 2011 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Michael J. Krische research group we are developing new transition metal catalyzed Carbon-Carbon (C-C) forming reactions focusing on atom economy and byproduct free, environmental friendly approaches. We have developed a broad family of C-C bond forming hydrogenations with relative and absolute stereocontrol which provide an alternative to stoichiometric organometallic reagents in certain carbonyl and imine additions. Inspiring from the group work my goal was to develop new reactions, extend the scope of our group chemistry and their application towards synthesis of biologically active natural products. I have been part of enantioselective Rh catalyzed Aldol reaction of vinyl ketones to different aldehydes. Also, we have found that iridium catalyzed transfer hydrogenation of allylic acetates in the presence of aldehydes or alcohols results in highly enantioselective carbonyl allylation under the conditions of transfer hydrogenative. Based on this reactivity a concise enantio- and diastereoselective synthesis of 1,3-polyols was achieved via iterative chain elongation and bidirectional iterative asymmetric allylation was performed, which enables the rapid assembly of 1,3-polyol substructures with exceptional levels of stereocontrol. The utility of this approach stems from the ability to avoid the use of chirally modified allylmetal reagents, which require multistep preparation, and the ability to perform chain elongation directly from the alcohol oxidation level. This approach was utilized for the total synthesis of (+)-Roxaticin from 1,3-propanediol in 20 longest linear steps and a total number of 29 manipulations. Further, advancements were made in iridium catalyzed C-C bond formation under transfer hydrogenation. While methallyl acetate does not serve as an efficient allyl donor, the use of more reactive leaving group in methallyl chloride compensate for the shorter lifetime of the more highly substituted olefin [pi]-complex. Based on this insight into the requirements of the catalytic process, highly enantioselective Grignard-Nozaki-Hiyama methallylation is achieved from the alcohol or aldehyde oxidation levels. Also, a catalytic method for enantioselective vinylogous Reformatsky- type aldol addition was developed in which asymmetric carbonyl addition occurs with equal facility from the alcohol or aldehyde oxidation level. Good to excellent levels of regioselectivity and uniformly high levels of enantioselectivity were observed across a range of alcohols and aldehydes.
Book Synopsis Transition Metal Catalyzed Regioselective Carbon-carbon Bond Formation Mediated by Transfer Hydrogenation by : Brannon Sam
Download or read book Transition Metal Catalyzed Regioselective Carbon-carbon Bond Formation Mediated by Transfer Hydrogenation written by Brannon Sam and published by . This book was released on 2015 with total page 1026 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Transition Metal Catalyzed Hydrogenative and Transfer Hydrogenative C-C Bond Formation by : Eduardas Skucas
Download or read book Transition Metal Catalyzed Hydrogenative and Transfer Hydrogenative C-C Bond Formation written by Eduardas Skucas and published by . This book was released on 2009 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-carbon bond formation is one the fundamental reactions in organic synthesis. The quest for the development of new and more efficient processes for the construction of this bond has been an ongoing focus for years. The transformations that permit the use of simple precursors to access complex structural architectures in the absence of stoichiometric quantities by-products are highly desirable. Hydrogen is a cheapest and cleanest reductant available to the mankind. The catalytic hydrogenation has been widely utilized in the industry, however the construction of the carbon-carbon bond under hydrogenative conditions has been achieved only for alkene hydroformylations and Fisher-Tropsh process and limited to the use of carbon monoxide. The extension of the hydrogenative carbon-carbon bond formations beyond aforementioned processes would be of a great significance to the synthetic community. The overview of allene use in the metal catalyzed reactions to achieve carbonyl and imine allylation and vinylation is presented in Chapter 1. The following chapter vii discusses the development of metal catalyzed hydrogenative and transfer hydrogenative coupling of allenes and carbonyl compounds to afford allylation products. These studies have resulted in the development of the first carbonyl allylation from the alcohol oxidation level. Chapter 3 discusses efforts towards achieving highly enantioselective hydrogenative coupling of alkynes to carbonyl compounds.
Book Synopsis Transition-metal-catalyzed C-C Bonds Formation Via Transfer Hydrogenation by : Gang Wang (Ph. D.)
Download or read book Transition-metal-catalyzed C-C Bonds Formation Via Transfer Hydrogenation written by Gang Wang (Ph. D.) and published by . This book was released on 2017 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: Redox-triggered carbonyl addition via transfer hydrogenation, which enables direct primary alcohol C-H functionalization to form C-C bond, avoids usage of premetalated reagents or discrete alcohol to aldehyde redox reactions. Moreover, step-economy could be greatly improved by site-selective transformations of polyfunctional molecules due to bypassing the need to install and remove protecting groups. However, the redox site-selective transformations still pose a significant challenge in the area of synthetic organic chemistry. Efforts have been focused on the development of iridium catalyzed transfer hydrogenative coupling reactions of primary alcohols with different allyl donors through carbonyl addition in a site-selective manner as well as ruthenium catalyzed regioselective hydrohydroxyalkylation of primary alcohols with a basic feedstock-styrene. Additionally, studies towards the total synthesis of type I polyketide natural product (+)-SCH 351448 in the most concise route is presented.
Book Synopsis Enantioselective C-C Bond Forming Reactions by :
Download or read book Enantioselective C-C Bond Forming Reactions written by and published by Elsevier. This book was released on 2023-12-01 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enantioselective C-C Bond Forming Reactions: From Metal Complex-, Organo-, and Bio-catalyzed Perspectives, Volume 73 in the Advances in Catalysis series, highlights new advances in the field, with this new volume presenting interesting chapters on topics such as An introduction to Chirality, Metal-catalyzed stereoselective C-C-bond forming reactions, Enantioselective C-C bond forming reactions promoted by organocatalysts based on unnatural amino acid derivatives, Enantioselective C-C bond formation in complex multicatalytic system, Gold-based multicatalytic systems for enantioselective C-C Bond forming reactions, Novel enzymatic tools for C-C bond formation through the development of new-to-nature biocatalysis, and more. - Provides the authority and expertise of leading contributors from an international board of authors - Presents the latest release in Advances in Catalysis serials - Updated release includes the latest information in the field
Book Synopsis Development of Neutral Redox Carbon-carbon Bond Forming Reactions Via Transition Metal-catalyzed Transfer Hydrogenation by : Khoa Dang Nguyen (Ph. D.)
Download or read book Development of Neutral Redox Carbon-carbon Bond Forming Reactions Via Transition Metal-catalyzed Transfer Hydrogenation written by Khoa Dang Nguyen (Ph. D.) and published by . This book was released on 2017 with total page 1316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since C-C bonds form the backbone of every organic molecule and reside at the heart of chemical science, the development of new efficient methods for promoting C-C bond formation is of great significance. Inspired and expanded from traditional Grignard reactions, the work presented in this dissertation focuses on metal catalyzed neutral redox-triggered carbonyl addition via transfer hydrogenation. Advancing the native reducing capability of alcohols, employment of catalytic transition metals enables the formation of nucleophile-electrophile pairs in situ, en route to the products of formal alcohol C-H functionalization. These redox-triggered reactions circumvent the stoichiometric metallated byproduct waste and streamline the construction of complex molecules from simple and/or readily available feedstocks. The research reported herein discloses new developed methodologies of ruthenium and iridium catalyzed coupling reactions of primary and secondary alcohols with various pi-unsaturates. These studies contribute to the growing body of redox-triggered alcohol C-C couplings - new carbonyl addition chemistry that extends beyond the use of premetalated reagents.
Book Synopsis Transition Metal Catalyzed Redox Triggered C–C Bond Forming Reactions of Alcohols Via Transfer Hydrogenation by : Boyoung Park
Download or read book Transition Metal Catalyzed Redox Triggered C–C Bond Forming Reactions of Alcohols Via Transfer Hydrogenation written by Boyoung Park and published by . This book was released on 2016 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbonyl addition is one of the fundamental reactions forming C–C bonds in organic chemistry to construct structurally complex organic molecules, in particular natural products, from small molecules. For this useful carbonyl addition, transition metal catalyzed redox-triggered C–C bond forming reactions of alcohols have been developed via transfer hydrogenation. Combined redox events are more efficient in terms of step- and atom-economy by delivering nucleophile-electrophile pairs in situ from [pi]-unsaturates and alcohols, respectively. Furthermore, transition metal catalyzed redox-triggered C–C couplings bypass the need of stoichiometric (organo)metallic reagents. This dissertation shows the development of new methodologies for this goal including prenylation, vinylation, alkylation and allylation using various ruthenium, osmium and iridium catalysts.
Book Synopsis Transition Metal Catalyzed Reductive Couplings Under Hydrogenative and Transfer Hydrogenative Conditions by : Vanessa Monet Williams
Download or read book Transition Metal Catalyzed Reductive Couplings Under Hydrogenative and Transfer Hydrogenative Conditions written by Vanessa Monet Williams and published by . This book was released on 2010 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental concerns have birthed an awareness of how we conduct ourselves as citizens of this planet. To reduce environmental impact, we have learned that we must be responsible stewards in all ranges of life: from buying locally grown food to how scientific research and industrial processes are executed. In the realm of chemical research, "green chemistry" has initiated the development of new, sustainable methods that make use of atom economy, step economy, and utilize renewable materials to minimize waste and production of toxic by-products. The formation of carbon-carbon bonds lies at the very heart of organic synthesis, and traditional methods for forming such bonds generally require the use of at least one stoichiometrically preformed organometallic reagent. This corresponds to at least one equivalent of metallic waste byproduct. The in situ formation of alkyl metal nucleophiles for carbonyl additions via hydrogenation of [pi]-unsaturates represents an alternative to use of preformed organometallic reagents. Comprising nearly 90% of the atoms in the universe, hydrogen is vastly abundant and very cheap. The Krische group seeks to contribute new technologies which make use of catalytic hydrogenation and transfer hydrogenation in the reductive coupling of basic chemical feedstocks.
Book Synopsis C-X Bond Formation by : Arkadi Vigalok
Download or read book C-X Bond Formation written by Arkadi Vigalok and published by Springer Science & Business Media. This book was released on 2010-07-09 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Kilian Muñiz: Transition Metal Catalyzed Electrophilic Halogenation of C-H bonds in alpha-Position to Carbonyl Groups; Arkadi Vigalok * and Ariela W Kaspi: Late Transition Metal-Mediated Formation of Carbon-Halogen Bonds; Paul Bichler and Jennifer A. Love*: Organometallic Approaches to Carbon-Sulfur Bond Formation; David S. Glueck: Recent Advances in Metal-Catalyzed C-P Bond Formation; Andrei N. Vedernikov: C-O Reductive Elimination from High Valent Pt and Pd Centers; Lukas Hintermann: Recent Developments in Metal-Catalyzed Additions of Oxygen Nucleophiles to Alkenes and Alkynes; Moris S. Eisen: Catalytic C-N, C-O and C-S bond formation promoted by organoactinide complexes.
Book Synopsis Transition Metal-Catalyzed Carbene Transformations by : Jianbo Wang
Download or read book Transition Metal-Catalyzed Carbene Transformations written by Jianbo Wang and published by John Wiley & Sons. This book was released on 2022-05-16 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents an up-to-date overview of the rapidly growing field of carbene transformations Carbene transformations have had an enormous impact on catalysis and organometallic chemistry. With the growth of transition metal-catalyzed carbene transformations in recent decades, carbene transformations are today an important compound class in organic synthesis as well as in the pharmaceutical and agrochemical industries. Edited by leading experts in the field, Transition Metal-Catalyzed Carbene Transformations is a thorough summary of the most recent advances in the rapidly expanding research area. This authoritative volume covers different reaction types such as ring forming reactions and rearrangement reactions, details their conditions and properties, and provides readers with accurate information on a wide range of carbene reactions. Twelve in-depth chapters address topics including carbene C-H bond insertion in alkane functionalization, the application of engineered enzymes in asymmetric carbene transfer, progress in transition-metal-catalyzed cross-coupling using carbene precursors, and more. Throughout the text, the authors highlight novel catalytic systems, transformations, and applications of transition-metal-catalyzed carbene transfer. Highlights the dynamic nature of the field of transition-metal-catalyzed carbene transformations Summarizes the catalytic radical approach for selective carbene cyclopropanation, high enantioselectivity in X-H insertions, and bio-inspired carbene transformations Introduces chiral N,N'-dioxide and chiral guanidine-based catalysts and different transformations with gold catalysis Discusses approaches in cycloaddition reactions with metal carbenes and polymerization with carbene transformations Outlines multicomponent reactions through gem-difunctionalization and transition-metal-catalyzed cross-coupling using carbene precursors Transition Metal-Catalyzed Carbene Transformations is essential reading for all chemists involved in organometallics, including organic and inorganic chemists, catalytic chemists, and chemists working in industry.
Book Synopsis Chemo-, Regio-, and Diastereoselective C-C and C-O Bond Formation Via Transition Metal Catalysis by : Nusrah Hussain
Download or read book Chemo-, Regio-, and Diastereoselective C-C and C-O Bond Formation Via Transition Metal Catalysis written by Nusrah Hussain and published by . This book was released on 2015 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficient stereoselective formation of C-C and C-O bonds remains a critical challenge in organic chemistry. The level difficulty of these bond formations increases dramatically when regio-, diastereo-, and chemoselectivity issues are present. In efforts to address such challenges, this thesis summarizes three successful strategies to develop highly stereoselective C-C and C-O bond formation reactions: 1) the first strategy outlines the direct metallation and subsequent chemo- and regioselective cross-coupling of benzylic sp3-hybridized C-H bonds (pKa values >34) to form C- bonds via palladium catalyzed deprotonative cross-coupling process (DCCP), 2) the second strategy outlines the application of 1,1-heterobimetallic borozinc reagents in the diastereoselective C- bond-forming reactions, and 3) the third strategy outlines the use of transition metal-catalysis in the highly chemo- and diastereoselective C-O bond formation via vanadium catalyzed directed epoxidation. Chapters 1 and 2 summarize a program that we have recently initiated in our laboratory known as deprotonative cross-coupling process (DCCP). DCCP is the reversible in situ deprotonation of weakly acidic sp3-hybridized C-H bonds under mild conditions, which are then catalytically cross-coupled with aryl electrophiles under palladium catalysis. Chapters 3 and 4 summarize the potential usefulness of 1-alkenyl-l,l-heterobimetallics in the stereoselective C-C bond formations in organic synthesis. Our group reported a practical generation of 1,1-heterobimetallics from air-stable B(pin)-substituted alkynylboronate esters and demonstrated their utility in a variety of one-pot transformations to provide boron-substituted allylic alcohols, dienols, [alpha]-hydroxy ketones, and [alpha]-dihydroxy ketones with high diastereoselectivity. More applications of these reagents are also explored in Chapters 3 and 4.
Book Synopsis Metal Catalyzed Reductive C-C Bond Formation by : Michael J Krische
Download or read book Metal Catalyzed Reductive C-C Bond Formation written by Michael J Krische and published by Springer Science & Business Media. This book was released on 2007-10-05 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions by numerous experts
