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 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 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 C2 and C3 Symmetric Chiral Bis and Tris phosphines in Asymmetric Catalysis written by Zhiming Xu and published by . This book was released on 2017 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1. Effect of linker length on selectivity and cooperative reactivity in platinum-catalyzed asymmetric alkylation of bis(phenylphosphino)alkanes. The selectivity of catalytic asymmetric transformations of bifunctional symmetrical substrates often depends on the linker between the two reactive sites. If the catalyst controls the selectivity of reactions at both sites, the rac product will be formed in high enantiomeric ratio (er) via asymmetric amplification. Substrate control may augment this selectivity (positive cooperativity) or detract from it (negative cooperativity). We investigated the effect of linker length on the selectivity of catalytic asymmetric alkylation of the bis(secondary phosphines) PhHP-(CH2)[subscript n]PHPh (n = 2-6, 1a-e) with benzyl bromide using the base NaOSiMe3 and the catalyst precursor Pt((R,R)-Me-DuPhos)(Ph)(Cl). The two alkylations of bis(secondary phosphines) 1b-e with longer linker lengths (n = 3-6) showed identical selectivity, within experimental error. This catalyst control resulted in asymmetric amplification of rac-2. In contrast, the selectivity of the first alkylation of ethano-bridged 1a was lower than that in 1b-e (negative cooperativity), but the selectivity of the second alkylation increased due to positive cooperativity. I developed an efficient synthesis of the intermediate PhHP(CH2)2PPh(CH2Ph) (3a), which was required for determination of the selectivity of both steps in Pt-catalyzed alkylation of 1a. Possible mechanistic explanations for the observed dependence of selectivity on linker length are discussed in this chapter. Chapter 2. Selective formation of a C3-symmetric P-stereogenic tris(phosphine) via platinum-catalyzed asymmetric alkylation of a tris(secondary phosphine). C2-symmetric bis(phosphines) are the most common and successful ligands for metal-catalyzed reactions. Considering the great success of C2-symmetric ligands in asymmetric catalysis, C3-symmetric chiral tris(phosphines) were proposed to be useful in octahedral complexes, creating three homotopic sites. However, very little is known about C3-symmetric tris(phosphines) and their applications, mostly because of the lack of synthetic routes. We used Pt-catalyzed asymmetric alkylation to prepare enantiomerically enriched C3-symmetric, P-stereogenic tripodal tris(phosphines) from the tris(secondary phosphine) MeC(CH2PHPh)3 (5 a racemic mixture of C1- and C3-symmetric diastereomers) and a benzl bromide, utilizing the Pt((R,R)-Me-Duphos)(Ph)(Cl) catalyst precursor and a base. Pt-catalyzed alkylation of MeC(CH2PHPh)3 (5) with 2-cyanobenzyl bromide gave a mixture of tris(phosphines) MeC(CH2PPh(CH2Ar))3 (6) enriched in C3-6; oxidation of 6 by sulfur or H2O2 formed phosphine sulfide S-6 and oxide O-6. Hydrogen bonding between O-6 and the chiral amino acid (S)-Fmoc-Trip(BOC)-OH leads to the formation of new diastereomers. By integrating the 31P NMR spectra, I measured the dr and er values. Tris(phosphine) 6 was formed with a disatereomeric ratio (dr - C3/C1) of 2.1(2) and enantiomeric ratios of 54(10) and 3.8(7) for C3-3 and C1-3 respectively, which showed that the selectivity of the triple alkylation was not the same at each site (substrate control). Chapter 3. Screening racemic catalysts provides information on selectivity and mechanism in platinum-mediated asymmetric alkylation of bis- and tris(secondary phosphines). Screening racemic catalysts for transformations of symmetrical bifunctional substrates can provide information on the selectivity of an enantiopure catalyst. This idea was extended to Pt-catalyzed asymmetric alkylation of the bis(secondary phosphines) PhHP(CH2)3PHPh and PhHPCH2CMe2CH2PHPh and the tris(phosphine) MeC(CH2PHPh)3 with benzyl bromides using the catalyst precursors Pt(Me-DuPhos)(Ph)(CI) and Pt(BenzP*)(Ph)(CI). Depending on the catalyst and the substrate, these reactions occured under catalyst control without dissociation of the substrate, or under substrate control with or without substrate dissociation. The resulting structure-selectivity relationships provided mechanistic information. Chapter 4. Synthesis of new chiral bis(phospholane) metal-pincer complexes. Metal pincer complexes have received great attention in recent years as robust catalyst precursors. However, chiral metal pincer complexes for application in asymmetric catalysis are rare. Dialkylphospholane groups have an outstanding track record in asymmetric catalysis (commercial DuPhos and BPE ligands) and their steric properties can be easily controlled by tuning the alkyl substituents on the phospholane ring. These donors have similar steric and electronic properties to the common used bulky dialkylphosphine groups (P(t-Bu)2, P(i-Pr)2, etc.). Optimization of the synthesis of chiral PCP ligands bearing such phospholane groups and investigation of their coordination chemistry are discussed in this chapter.

Download or read book Ferrocenes written by Elisabeth S. Phillips and published by Nova Science Publishers. This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferrocene is an organometallic compound. It is the prototypical metallocene, a type of organometallic chemical compound consisting of two cyclopentadienyl rings bound on opposite sides of a central metal atom. Such organometallic compounds are also known as sandwich compounds. The rapid growth of organometallic chemistry is often attributed to the excitement arising from the discovery of ferrocene and its many analogues. This book presents current research from across the globe in the study of ferrocenes, including the synthesis of pristine and doped carbon nanotubes using ferrocene; the transition metal catalysed coupling and carbonylation reactions of ferrocene derivatives; and the exploitation of ferrocene for the development of mechanically interlocked and non-interlocked synthetic molecular machines.

Download or read book Ferrocene Chelating Heteroscorpionate Ligands Support Zinc Complexes as Redox Switchable Catalysts written by Tate Reuter and published by . This book was released on 2018 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferrocene-chelating heteroscorpionate compounds based on [fc(PPh2)(BH[(3-R-5-R'-1-H)2pz]2)] (fc = 1,1'-ferrocenediyl, pz = pyrazole) are studied and characterized for their role in the synthesis of block copolymers. The ferrocene scaffold is part of a heteroscorpionate ligand that supports late transition metals. A zinc complex, [fc(PPh2)(BH[(3,5-Me-1H)2pz]2)]Zn( -OCH2Ph), was synthesized previously and shown to exist in a dimeric state. Herein, the substituents on the pyrazole fragments of the scorpionate are replaced with bulkier groups to force the formation of a monomeric compound in order to arrive at a redox switchable catalyst.

Download or read book Synthesis of Yttrium and Aluminum Complexes Supported by a Mono Substituted Ferrocene Ligand written by Jun Gao and published by . This book was released on 2015 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferrocene chelating ligands provide good stability of the resulting metal complexes and redox-switchable control in chemical processes catalyzed by those complexes. In comparison to traditional di-substituted ferrocene tetradentate ligands, mono-substituted tridentate ferrocene ligands may form metal complexes with a more open coordination sphere around the metal center that may allow an increased preference for substrate coordination. In addition, a mono-substituted ferrocene ligand allows the investigation of the through bond influence of the ferrocenyl group on catalytic metal centers by increasing the metal-iron distance. In this thesis, the design, synthesis, and characterization by 1H NMR spectroscopy of a novel mono-substituted ferrocene ligand are described. To explore its ability to support metal complexes with high activity and redox-switchable in polymerization reactions, yttrium alkoxide and aluminum alkyl complexes were also synthesized and characterized by 1H NMR spectroscopy.

Download or read book Synthesis of Ferrocene based Ligands and Their Applications in Redox switchable Catalysis for Selective Hydroamination Reactions written by Brian Raymond Lydon and published by . This book was released on 2013 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis contains results from three different projects. The first project focused on the synthesis of monoanionic ferrocene-based N, P ligands. 1-(tert-butyldimethylsilyl)amino-1'-diphenylphosphinoferrocene (fc(TBSNH)(PPh2)) was successfully synthesized and characterized by 1H, 31P, 13C NMR spectroscopy, and elemental analysis. Unfortunately, coordination to group 3 metal complexes was unsuccessful. The second project focused on the synthesis of redox-active ferrocene-based ligands and their applications in selective intramolecular hydroamination. Redox-active ligands can be used as a reversible trigger to control catalytic reactivity. Preliminary results observed by 1H NMR spectroscopy suggest that [1,1'-ferrocenedi(thio(3,5-di-tert-butyl-2-phenoxide)]Zr dibenzyl ((thiolfan2)ZrBn2) shows selectivity between primary and secondary alkeneamines depending on the oxidation state of the iron center. The final project was a computational study using density functional theory (DFT) to understand recent experimental findings involving ferrocene-functionalized biodegradable polymers. Gibbs free energy for six cyclic carbonate monomers and three [delta]-valerolactone monomers was calculated. Computational results correlated strongly with experimental data in that [delta]-valerolactones, which could not be polymerized, had a higher Gibbs free energy than cyclic carbonates, which could be polymerized.

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 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 2005 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book C2 Symmetric Pyrazole Bridged Ligands and Their Application in Asymmetric Transition metal Catalysis written by Torben Böhnisch and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the scope of this thesis the synthesis of a plethora of examples of in total three types of C2-symmetric pyrazole-bridged ligand systems (namely PyrBOX, PyrBPyBOX and ProPyrazole) could be established (Chapter 4). Subsequently, the PyrBOX ligands proofed to be versatile ligands for asymmetric allylic substitution reactions (Chapter 7). Starting from three different palladium allyl precursors and four PyrBOX ligands in total twelve different complexes could be isolated. The investigations of these intermediate dinuclear allyl palladium complexes in solution (e.g., EX ...

Download or read book Metal Organic Frameworks written by Leonard R. MacGillivray and published by John Wiley & Sons. This book was released on 2010-12-17 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal-organic frameworks represent a new class of materials that may solve the hydrogen storage problem associated with hydrogen-fueled vehicles. In this first definitive guide to metal-organic framework chemistry, author L. MacGillivray addresses state-of-art developments in this promising technology for alternative fuels. Providing professors, graduate and undergraduate students, structural chemists, physical chemists, and chemical engineers with a historical perspective, as well as the most up-to-date developments by leading experts, Metal-Organic Frameworks examines structure, symmetry, supramolecular chemistry, surface engineering, metal-organometallic frameworks, properties, and reactions.

Download or read book Chiral Lewis Acids in Organic Synthesis written by Jacek Mlynarski and published by John Wiley & Sons. This book was released on 2017-10-23 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete overview covering the application of metal-based chiral Lewis acids from all parts of the periodic table, the Author emphasizes the most recent contributions to the field as well as prominent direction of development. The book discusses the design of chiral complexes as well as a wide spectrum of reactions promoted by various chiral Lewis acids, including water-compatible acids as well as the most important applications in the chemical and pharmaceutical industries. A must-have for catalytic and organic chemists working in the field, both in academia and industry, as well as pharmaceutical and medicinal chemists.

Download or read book Inorganometallic Chemistry written by Thomas P. Fehlner and published by Springer Science & Business Media. This book was released on 2013-11-22 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a certain fascination associated with words. The manipulation of strings of symbols according to mutually accepted rules allows a language to express history as well as to formulate challenges for the future. But language changes as old words are used in a new context and new words are created to describe changing situations. How many words has the computer revolution alone added to languages? "Inorganometallic" is a word you probably have never encountered before. It is one created from old words to express a new presence. A strange sounding word, it is also a term fraught with internal contradiction caused by the accepted meanings of its constituent parts. "In organic" is the name of a discipline of chemistry while "metallic" refers to a set of elements constituting a subsection of that discipline. Why then this Carrollian approach to entitling a set of serious academic papers? Organic, the acknowledged doyenne of chemistry, is distinguished from her brother, inorganic, by the prefix "in," i. e. , he gets everything not organic. Organometallic refers to compounds with carbon-metal bonds. It is simple! Inorganometallic is everything else, i. e. , compounds with noncarbon-metal element bonds. But why a new term? Is not inorganic sufficient? By virtue of training, limited time, resources, co-workers, and so on, chemists tend to work on a specific element class, on a particular compound type, or in a particular phase. Thus, one finds element-oriented chemists (e. g.

Download or read book Enantioselective Titanium catalysed Transformations written by Helene Pellissier and published by World Scientific. This book was released on 2016-01-15 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chiral titanium complexes are low-cost, low-toxicity and high-efficiency catalysts. Impressive progress on enantioselective titanium-catalysed transformations has been achieved in the past seven years, with exciting new discoveries ranging from basic reactions to novel methodologies. Despite this, the field has not been substantially reviewed since 2008.This book contains up to date research and covers all types of enantioselective transformations using chiral titanium catalysts. It illustrates the economic, health, and environmental benefits of chiral titanium catalysts, showing the types of highly enantioselective reactions that they are able to induce are unlimited.Work presented here is aimed at researchers in organic and catalytic chemistry, and has been carefully curated to encourage future research possibilities.

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.

Download or read book Comprehensive Coordination Chemistry II written by J. A. McCleverty and published by Newnes. This book was released on 2003-12-03 with total page 11845 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Coordination Chemistry II (CCC II) is the sequel to what has become a classic in the field, Comprehensive Coordination Chemistry, published in 1987. CCC II builds on the first and surveys new developments authoritatively in over 200 newly comissioned chapters, with an emphasis on current trends in biology, materials science and other areas of contemporary scientific interest.