Download or read book New Developments in Late Transition Metal Complexes of Ferrocene Based Ligands and Study of Their Efficiency as Catalysts in Asymmetric Reactions written by Marta Ayerbe Garcia and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chiral Ferrocenes in Asymmetric Catalysis written by Li-Xin Dai and published by John Wiley & Sons. This book was released on 2010-02-01 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book meets the long-felt need for a reference on ferrocenes with the focus on catalysis. It provides a thorough overview of the synthesis and characterization of different types of chiral ferrocene ligands, their application to various catalytic asymmetric reactions, and versatile chiral materials as well as drug intermediates synthesized from them. Written by the "who's who" of ferrocene catalysis, this is a guide to the design of new ferrocene ligands and synthesis of chiral synthetic intermediates, and will thus be useful for organic, catalytic and synthetic chemists working in academia, industrial research or process development.
Download or read book Artificial Metalloenzymes and MetalloDNAzymes in Catalysis written by Montserrat Diéguez and published by John Wiley & Sons. This book was released on 2018-02-21 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important reference for researchers in the field of metal-enzyme hybrid catalysis Artificial Metalloenzymes and MetalloDNAzymes in Catalysis offers a comprehensive review of the most current strategies, developed over recent decades, for the design, synthesis, and optimization of these hybrid catalysts as well as material about their application. The contributors—noted experts in the field—present information on the preparation, characterization, and optimization of artificial metalloenzymes in a timely and authoritative manner. The authors present a thorough examination of this interesting new platform for catalysis that combines the excellent selective recognition/binding properties of enzymes with transition metal catalysts. The text includes information on the various applications of metal-enzyme hybrid catalysts for novel reactions, offers insights into the latest advances in the field, and contains an informative perspective on the future: Explores the development of artificial metalloenzymes, the modern and strongly evolving research field on the verge of industrial application Contains a comprehensive reference to the research area of metal-enzyme hybrid catalysis that has experienced tremendous growth in recent years Includes contributions from leading researchers in the field Shows how this new catalysis combines the selective recognition/binding properties of enzymes with transition metal catalysts Written for catalytic chemists, bioinorganic chemists, biochemists, and organic chemists, Artificial Metalloenzymes and MetalloDNAzymes in Catalysis offers a unique reference to the fundamentals, concepts, applications, and the most recent developments for more efficient and sustainable synthesis.
Download or read book Asymmetric Organocatalysis Combined with Metal Catalysis written by Bruce A. Arndtsen and published by Springer Nature. This book was released on 2020-04-24 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book C H Activation for Asymmetric Synthesis written by Françoise Colobert and published by John Wiley & Sons. This book was released on 2019-11-11 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides, in one handbook, comprehensive coverage of one of the hottest topics in stereoselective chemistry Written by leading international authors in the field, this book introduces readers to C-H activation in asymmetric synthesis along with all of its facets. It presents stereoselective C-H functionalization with a broad coverage, from outer-sphere to inner-sphere C-H bond activation, and from the control of olefin geometry to the induction of point, planar and axial chirality. Moreover, methods wherein asymmetry is introduced either during the C-H activation or in a different elementary step are discussed. Presented in two parts?asymmetric activation of C(sp3)-H bonds and stereoselective synthesis implying activation of C(sp2)-H bonds?CH-Activation for Asymmetric Synthesis showcases the diversity of stereogenic elements, which can now be constructed by C-H activation methods. Chapters in Part 1 cover: C(sp3)-H bond insertion by metal carbenoids and nitrenoids; stereoselective C-C bond and C-N bond forming reactions through C(sp3)?H bond insertion of metal nitrenoids; enantioselective intra- and intermolecular couplings; and more. Part 2 looks at: C-H activation involved in stereodiscriminant step; planar chirality; diastereoselective formation of alkenes through C(sp2)?H bond activation; amongst other methods. -Covers one of the most rapidly developing fields in organic synthesis and catalysis -Clearly structured in two parts (activation of sp3- and activation of sp2-H bonds) -Edited by two leading experts in C-H activation in asymmetric synthesis CH-Activation for Asymmetric Synthesis will be of high interest to chemists in academia, as well as those in the pharmaceutical and agrochemical industry.
Download or read book Ferrocenes written by Petr Stepnicka and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferrocene—the prototypical metallocene—is a fascinating molecule. Even though it was first discovered over fifty years ago, research into ferrocene-containing compounds continues apace, largely stimulated by their successful applications in catalysis, materials science and bioorganometallic chemistry. Ferrocene derivatives are now recognised as useful starting materials for the preparation of new organometallic complexes and functional materials, efficient catalyst components, as well as redox-active modifiers to biomolecules. Ferrocenes: Ligands, Materials and Biomolecules provides the reader with a background overview and describes recent advances in the development and application of ferrocene compounds, including: synthesis and catalytic utilisation of chiral and non-chiral ferrocene ligands ferrocene-based sensors electrooptical materials ferrocene polymers liquid-crystalline materials crystal engineering with ferrocene compounds the bioorganometallic chemistry of ferrocene Ferrocenes: Ligands, Materials and Biomolecules is an essential guide for anyone working in the fields of organometallic synthesis and catalysis, materials science and bioorganometallic chemistry.
Download or read book Symmetrically and Non symmetrically Substituted 1 1 ferrocenes as Supporting Ligands for Divalent Metals in Catalysis written by Mark Abubekerov and published by . This book was released on 2017 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis of new polymers is motivated by the limitations of current materials. Recently, interest in copolymers containing blocks that display different or complementary properties has been increasing since these materials have potential for further performance enhancements. Inspired by recent developments in olefin polymerization catalysts, and based on the interest of the Diaconescu group in the reactivity of complexes supported by ferrocene-based chelating ligands, we developed a new ferrocene-chelating heteroscorpionate supporting ligand and investigated its applications in combination with late transition metals to redox-switchable catalysis for the production of multiblock copolymers. Additionally, we began investigations into the influence of the iron-secondary metal interactions on redox-switchable catalysis in complexes supported by symmetrically substituted, neutral ferrocene-based ligands.
Download or read book Synthesis of Metal Complexes Supported by Ferrocene based Ligands for Tandem Catalysis and Applications Toward Liquid Cell Quantum Sensing written by Yi Shen and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developing methodologies to synthesize high-value products efficiently from simple substrates with control over the reactivity and selectivity is highly favored by the chemical industry. Employing assisted tandem catalysis, where serial reactions can be carried out in one pot, to achieve streamlined complex syntheses significantly reduces the number of steps and waste. Harnessing spatial and temporal control in catalysis enables approaches toward one-pot transformations and allows the integration of several catalytic processes. Ferrocene-based ligand-supported metal complexes represent a promising class of catalysts that can incorporate redox control over catalytic processes. We have developed a redox-controlled selective hydroamination reaction catalyzed by (thiolfan*)Zr(NEt2)2 (thiolfan*= 1, 1'-bis (2,4-di-tert-butyl-6-thiophenoxy)ferrocene). In situ switching of the catalyst's state during the reaction enables selectivity toward different substrates (Chapter 2).Incorporating the greenhouse gas CO2 into N-carboxyanhydrides (NCAs) followed by subsequent NCA utilization illustrates the possibility of integrating two synthetic steps in one vessel to afford a valuable material with possible CO2 recycling. To demonstrate the immense potential of integrating multi-step transformations in one pot, we developed a set of sustainable conditions for NCA synthesis (Chapter 3). Moreover, several metal catalysts supported by ferrocene-based ligands were found to catalyze NCA polymerization in the presence of a co-catalyst. To establish an integrated system composed of two incompatible processes, we aimed to compartmentalize the active reagents for each step. The structure of the ferrocene-based pro-ligand was modified for surface anchoring. Our efforts toward immobilizing ferrocene-supported metal catalysts onto conductive surfaces pave the way of achieving spatiotemporal control over the processes of NCA synthesis and polymerization (Chapter 4). In addition to the redox-switchable characteristic, ferrocene-based compounds provide a unique platform to support lanthanides and engender distinctive optical properties to them. We synthesized and characterized a series of ytterbium complexes displaying an ultra-narrow absorption in the ultraviolet-visible (UV-Vis) region. The extraordinarily narrow linewidth observed for (thiolfan)YbCl(THF) (thiolfan = 1,1'-bis(2,4-di-tert-butyl-6-thiomethylenephenoxy)ferrocene) allows us to investigate its applications toward magnetic field and liquid cell quantum sensing (Chapter 5).
Download or read book Machine Learning in Chemistry written by Jon Paul Janet and published by American Chemical Society. This book was released on 2020-05-28 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in machine learning or artificial intelligence for vision and natural language processing that have enabled the development of new technologies such as personal assistants or self-driving cars have brought machine learning and artificial intelligence to the forefront of popular culture. The accumulation of these algorithmic advances along with the increasing availability of large data sets and readily available high performance computing has played an important role in bringing machine learning applications to such a wide range of disciplines. Given the emphasis in the chemical sciences on the relationship between structure and function, whether in biochemistry or in materials chemistry, adoption of machine learning by chemistsderivations where they are important
Download or read book Asymmetric Dearomatization Reactions written by Shu-Li You and published by John Wiley & Sons. This book was released on 2016-09-13 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first comprehensive account of the rapidly growing field of asymmetric dearomatization reactions with a focus on catalytic methods. It introduces the concept of dearomatization and describes recent progress in asymmetric reaction procedures with different catalyst systems, such as organocatalysts, transition metal catalysts, and enzymes. Chapters on dearomatizations of electron-deficient aromatic rings, dearomatization reactions via transition metal-catalyzed cross-couplings as well as dearomatization strategies in the synthesis of complex natural products are also included. Written by pioneers in the field, this is a highly valuable source of information not only for professional synthetic chemists in academia and industry but also for all those are interested in asymmetric methodologies and organic synthesis in general.
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2007 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Iron Chemistry of Hemilabile SNS Ligands written by Uttam Das and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of abundant and economical first-row transition metal-based catalysts is an appealing area of research for efficient and selective chemical transformations. In this context, iron complexes are highly desirable as they feature a range of accessible oxidation states allowing for transfer of one or two electrons to or from a substrate. Therefore, over the past two decades, many iron-based catalysts have been developed, extensively studied, and exploited for catalysis ranging from oxidation and reduction to C-C bond forming reactions. In homogeneous transition metal catalysis, the ligand plays a vital role in determining activity and selectivity of the above stated catalytic reactions. Some key features of ligands that support both stoichiometric and catalytic reactions of metal complexes include: 1) strong chelation ability to metals, 2) tunability of donor atoms, 3) strong field ligands such as phosphine, phosphite, CO, and hydride favoring low-spin complexes, 4) hemilability allowing substrate activation via reversible dissociation of one donor atom, and 5) redox-activity enabling donation or accepting of electrons, thus avoiding a change of metal oxidation state. To this end, bifunctional ligands containing the above described properties have emerged as important elements in chemical synthesis and in catalysis. Iron and other transition metal complexes containing multidentate bifunctional ligands have recently been shown to activate small molecules and catalyze a number of chemical transformations with activity and selectivity typical of more well-studied precious metals. The objective of this thesis is to further advance the field of bifunctional ligands by preparing new sterically svelte tridentate ligands with a mixture of hard nitrogen and soft sulfur donors and to investigate their iron chemistry. The overall goal is to then explore the utility of these iron complexes as potential bifunctional catalysts. Chapter 2 describes a one-step synthesis of a new SMeNHS ligand in excellent yield that undergoes ring-opening on treatment with Fe(OTf)2 affording a thiolate-bridged, trinuclear iron complex, [Fe3(μ2-SMeNS−)4](OTf)2. The structure, spectroscopic, magnetic, and computational studies of this iron complex are provided along with its solvent-dependent reactivity towards monodentate donor ligands that yields both dinuclear and mononuclear derivatives. Chapter 3 describes the formation of an electron-rich Fe(II) thiolate complex, [Fe(SMeNS)(PMe3)3](OTf) and its substitution reactivity with both mono- and bidentate donor ligands. On heating this complex, an oxidative thioether Caryl-S bond cleavage is observed, leading to a cationic Fe(III)-CNS thiolate analog. Reduction of this Fe(III) species with cobaltocene yielded a neutral Fe(II)-CNS thiolate complex. To investigate the bifunctional activity of these Fe(II) complexes, both Fe(II)-SNS and -CNS species were assessed as precatalysts for amine-borane dehydrogenation. Chapter 4 employs the SMeNHS ligand in formation of a neutral, imine-coupled Fe-N2S2 complex that serves as an efficient and selective aldehyde hydroboration catalyst using pinacolborane. A reaction profile kinetic analysis implicates the hemilability and redox-active properties of this complex. Chapter 5 introduces the new unsymmetrical amine ligand, SMeNHSMe, and details its iron chemistry with formation of a pseudooctahedral Fe(II) bis(amido) complex. The Mössbauer spectra, MCD study, and DFT calculations support formation of a minor five-coordinate isomer in solution due to the hemilability of the six-membered ring thioether group. Reactivity studies of this Fe(II) species with a variety of donor ligands confirmed this lability and protonation at nitrogen yielded a cationic Fe(II) amine-amido complex. Reaction of the latter with the tridentate phosphine, triphos, gave a 16e-, low-spin, square-pyramidal Fe(II) complex that proved to be a robust precatalyst that is more active for dehydrogenation of dimethylamine-borane vs. ammonia-borane. Formation of a monohydride catalyst resting state under these reaction conditions is suggestive of a bifunctional activation pathway. Finally, Chapter 6 concludes the outcomes of the iron chemistry of hemilabile SNS ligands and discusses future directions and opportunities to extend these ligand systems to other transition metals. The knowledge gained by the stoichiometric and catalytic reactivity of iron-SNS complexes presented herein contributes to our understanding of bifunctional catalysis. With the increasing demand for base metal catalysts in chemical industry for efficient and selective synthesis of value-added chemicals, iron SNS complexes could offer economical, active, and selective catalyst precursors.
Download or read book Vanadium Catalysis written by Manas Sutradhar and published by Royal Society of Chemistry. This book was released on 2020-11-05 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vanadium is one of the more abundant elements in the Earth’s crust and exhibits a wide range of oxidation states in its compounds making it potentially a more sustainable and more economical choice as a catalyst than the noble metals. A wide variety of reactions have been found to be catalysed by homogeneous, supported and heterogeneous vanadium complexes and the number of applications is growing fast. Bringing together the research on the catalytic uses of this element into one essential resource, including theoretical perspectives on proposed mechanisms for vanadium catalysis and an overview of its relevance in biological processes, this book is a useful reference for industrial and academic chemists alike.
Download or read book Bulletin of the Korean Chemical Society written by and published by . This book was released on 2002 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Search for Catalysts Using the Cooperativity of Transition Metals and Heterocyclic Ligands written by Sang Van and published by . This book was released on 2002 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of new and efficient catalysts plays an important role in chemical research. The inspiration for finding new catalysts includes long-term benefits such as (a) efficient, atom-economical reactions; (b) chemoselective reactions under mild conditions, obviating the need for protection and deprotection of functional groups; and (c) reduction of chemical waste in the production of fine chemicals for pharmaceuticals. For these purposes, artificial enzyme mimics are exploited. In the preparation of such catalysts, a promising approach is to translate the principles of enzyme catalysis for the design of new catalytic materials. In this research, we used design features of the cooperativity of Lewis acid transition metals and heterocyclic ligands designed to provide hydrogen bond donor (A) and acceptor (B), inspired by Nature's enzymes, to catalyze reactions of polar molecules such as water, alcohols, or amines with organic molecules.* To synthesize our catalysts, we envisioned anchoring a transition metal to a heterocycle which features a reasonably acidic N-H group (A). In this research, we prepared 10 pyrazole ligands and 35 of their complexes, 15 of which were analyzed by X-ray diffraction. Furthermore, isoelectronic and isosteric complexes incapable of donating or accepting hydrogen bond(s) were also synthesized to determine the relationship between hydrogen-bond donating properties and catalytic efficiency. All the complexes were characterized by NMR spectroscopy, IR spectroscopy, and elemental analysis. Part of our studies to date have focused on the hydrolysis of unactivated amide bonds, thought to be a more difficult challenge than similar reactions of phosphate diesters. We also focused on the use of hydrogen-donating-group-assisted in catalysis of chemoselective hydrogenation of imines. We also used bifunctional catalysts to catalyze regio- and stereoselective dimerization of terminal alkynes, and hydrogen transfer hydrogenation of aldehydes, ketones, and imines. The catalysts can also catalyze cyclization and coupling reactions of alkynols. Significantly, these catalytic processes involve both C-C and C-O bond formation with diastereo- and regioselectivity. These results are fruitful because we have opened another field of catalysis using the combined effects of hydrogen-bond donating ligands and Lewis acidic transition metals. *Please refer to dissertation for diagrams.
Download or read book Late Transition Metal Complexes for E H Bond Activation and Additions to Multiple Bonds written by Kevin Hesp and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Asymmetric Synthesis written by Takahiko Akiyama and published by John Wiley & Sons. This book was released on 2022-05-27 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalytic Asymmetric Synthesis Seminal text presenting detailed accounts of the most important catalytic asymmetric reactions known today This book covers the preparation of enantiomerically pure or enriched chemical compounds by use of chiral catalyst molecules. While reviewing the most important catalytic methods for asymmetric organic synthesis, this book highlights the most important and recent developments in catalytic asymmetric synthesis. Edited by two well-qualified experts, sample topics covered in the work include: Metal catalysis, organocatalysis, photoredox catalysis, enzyme catalysis C–H bond functionalization reactions Carbon–carbon bond formation reactions, carbon–halogen bond formation reactions, hydrogenations, polymerizations, flow reactions Axially chiral compounds Retaining the best of its predecessors but now thoroughly up to date with the important and recent developments in catalytic asymmetric synthesis, the 4th edition of Catalytic Asymmetric Synthesis serves as an excellent desktop reference and text for researchers and students, from upper-level undergraduates all the way to experienced professionals in industry or academia.
