Download or read book Synthesis and Evaluation of Novel Bidentate Ligands for Transition Metal mediated Asymmetric Catalysis written by Dennis Mc Cartney and published by . This book was released on 2013 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metal Mediated Template Synthesis of Ligands written by Otilia Costisor and published by World Scientific. This book was released on 2004 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book surveys the relatively new area of the synthesis of organic ligands when metal ions act as a template. In the last fifty years this field has undergone an explosive development, marked by a great amount of literature. The material in the book has been arranged according to the type of chemical reaction involved. In this frame, the basic principles of metal template reactions and the shape of the molecules are considered. Designed to satisfy the demands of students, young researchers doing their PhDs, and those working in the field of coordination chemistry, the book details the role of the metal ions and the specific properties of the formed complexes. Metal Mediated Template Synthesis of Ligands offers a comprehensive analysis with wide-ranging references and provides an extensive overview of research on metal-directed organic ligands over the past five decades. Contents: The Template Effect; Alkylation Reactions; Schiff Condensation; Mannich Condensation; Self Condensation of Nitriles; Self-Assembled Systems. Readership: Upper level undergraduates, graduate students, academics, researchers industrialists in inorganic, solid-state, supramolecular and organic chemistry.

Download or read book Ligand Design in Metal Chemistry written by Mark Stradiotto and published by John Wiley & Sons. This book was released on 2016-09-01 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of ancillary ligands used to modify the structural and reactivity properties of metal complexes has evolved into a rapidly expanding sub-discipline in inorganic and organometallic chemistry. Ancillary ligand design has figured directly in the discovery of new bonding motifs and stoichiometric reactivity, as well as in the development of new catalytic protocols that have had widespread positive impact on chemical synthesis on benchtop and industrial scales. Ligand Design in Metal Chemistry presents a collection of cutting-edge contributions from leaders in the field of ligand design, encompassing a broad spectrum of ancillary ligand classes and reactivity applications. Topics covered include: Key concepts in ligand design Redox non-innocent ligands Ligands for selective alkene metathesis Ligands in cross-coupling Ligand design in polymerization Ligand design in modern lanthanide chemistry Cooperative metal-ligand reactivity P,N Ligands for enantioselective hydrogenation Spiro-cyclic ligands in asymmetric catalysis This book will be a valuable reference for academic researchers and industry practitioners working in the field of ligand design, as well as those who work in the many areas in which the impact of ancillary ligand design has proven significant, for example synthetic organic chemistry, catalysis, medicinal chemistry, polymer science and materials chemistry.

Download or read book The Synthesis of Asymmetric Ligands for Transition Metal Catalysis written by J. T. G. Taylor Gomes and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Synthesis of New Ligand Systems for Transition Metal Catalysed Carbon carbon Cross coupling Hydrogenation and Hydrosilation written by Daniel Carleton and published by . This book was released on 2013 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ever increasing global requirement for consumables consequently increases the demand for often non-renewable resources, resulting in the need for greater efficiencies in synthetic processes. In order to achieve this goal, the field of organometallic catalysis has been ever growing to support the ideals of cleaner and greener chemistry. In this thesis studies concerning a series of new bidentate donor ligands employing both the NHC and PYA donor groups for use in transition metal catalysis is presented. The successful synthesis of the bidentate ligand N,N'-dimethyl-N''-pyridin-4-yl nicotinamide with both a remote NHC and PYA donor groups is reported, along with the synthesis of the precursor materials 1-methyl-3-(2-oxo-2-(pyridin-2-ylamino)ethyl)-1H-imidazol-3-ium and 1-methyl-3-(2-oxo-2-(pyridin-4-ylamino)ethyl)-1H-imidazol-3-ium for the formation of other bidentate ligands incorporating the imidazolium NHC and PYA donor groups. The iridium complex IrH(L-R4)(CO)(PPh3)2 containing the new ligand L-R4 was prepared through reaction of N,N'-dimethyl-N''-pyridin-4-yl nicotinamide with Vaskas Complex. Chapter one explains the ideology behind green chemistry and our constant drive to maintain a clean and green planet. Chapter two describes the effect of donor groups on a metal centre with focus on the NHC and PYA donor groups and their advantages over previous work in this area. Chapter three describes the development of synthetic routes to the new target ligands and chapter four explains the studies involving the metal precursor substrates and ligand coordination. Chapter five contains details of the relevant experimental data. The work described in this thesis will provide an excellent starting point for those wishing to further explore the synthesis and study of bidentate NHC and PYA donor ligands in catalysis by transition metals.

Download or read book Synthesis and Application of New Chiral Ligands for Enantioselectivity Tuning in Transition Metal Catalysis written by Fanji Kong and published by . This book was released on 2017 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: A set of five new C3-symmetric phosphites were synthesized and tested in palladium-catalyzed asymmetric Suzuki coupling. The observed reactivity and selectivity were dependent upon several factors. One of the phosphites was able to achieve some of the highest levels of enantioselectivity in asymmetric Suzuki couplings with specific substrates. Different hypotheses have been made for understanding the ligand effects and reaction selectivities, and those hypotheses were tested via various methods including DOSY NMR experiments, X-ray crystallography, and correlation of catalyst selectivity with Tolman cone angles. Although only modest enantioselectivities were observed in most reactions, the ability to synthesis these phosphites in only three steps on gram scales and to readily tune their properties by simple modification of the binaphthyl 2́-substituents makes them promising candidates for determining structure-selectivity relationships in asymmetric transition metal catalysis, in which phosphites have been previously shown to be successful. A series of novel chiral oxazoline-based carbodicarbene ligands was targeted for synthesis. Unfortunately, the chosen synthetic route could not be completed due to unwanted reactivity of the oxazoline ring. However, a new and efficient route for Pd-catalyzed direct amination of aryl halides with oxazoline amine was developed and optimized during these studies. Chiral binaphthyl based Pd(II) ADC complexes with different substituent groups have been synthesized and tested in asymmetric Suzuki coupling reactions. Although only low enantioselectivities were observed in Suzuki coupling, this represents a new class of chiral metal-ADC catalysts that could be tested in further catalytic.

Download or read book Engineering of Modular Ligands for Asymmetric Catalysis written by Francesc Xavier Caldentey Frontera and published by . This book was released on 2009 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Novel Chiral Di N heterocyclic Carbene and Hybrid Phosphine N heterocyclic Carbene Ligands and Their Application to Transition Metal Mediated Asymmetric Catalysis written by and published by . This book was released on 2005 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Screening of Novel Ligands for Asymmetric Catalysis written by Mark Timothy Powell and published by . This book was released on 2001 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Application of Water soluble Ligand Systems for Transition metal Mediated Catalysis written by Fida'a S. Al-Masri 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 Design Synthesis and Evaluation of Chiral Nonracemic Ligands and Catalysts for Asymmetric Synthesis written by Michael P. A. Lyle and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work described in this thesis concerns the design, synthesis and evaluation of new chiral nonracemic ligands and catalysts for use in asymmetric reactions. A series of chiral nonracemic chloroacetals were prepared from 2-chloro-4- methyl-6,7-dihydro-5H-[l]pyrindine-7-one and a variety of C2-symmetric and chiral nonracemic 1,2-ethanediols (R = Me, i-Pr and Ph). These chloroacetals were further elaborated, in a modular fashion, to provide a series of chiral ligands and catalysts. A new class of C2-symmetric 2,2'-bipyridyl ligands were prepared in one step fiom the chloroacetals via a nickel(0)-mediated homo-coupling reaction. These ligands were then evaluated as chiral directors in copper@)-catalyzed asymmetric cyclopropanation reactions of styrene and diazoesters (up to 44% ee). A chiral pyridine N-oxide and a C2-symmetric 2,2'-bipyridyl N, N'-dioxide were also prepared by direct oxidation of the corresponding pyridine and the 2,2'-bipyridine, respectively. These chiral N-oxides were evaluated as chiral catalysts in desymmeterization reactions of cis-stilbene oxide (up to 20% ee). A series of pyridylphosphine ligands (P, N-ligands) were subsequently prepared in two steps from the chloroacetals via a Suzuki coupling reaction with orthofluorophenylboronic and on subsequent displacement of the fluoride with the potassium anion of diphenylphosphine. These ligands were then evaluated in palladium-catalyzed asymmetric allylic substitution reactions of racemic 3-acetoxy-l,3-diphenyl-1-propene with dimethyl malonate. Optimization of the reaction conditions resulted in the formation of the alkylated product in excellent yield (91%) and in high enantiomeric excess (90%). A related chiral nonracemic and C2-symmetric 2,2'-bipyridyl ligand was prepared from 2-chloro-4-methyl-5H-[llpyrindine. This pyrindine was prepared from a common intermediate that was used in the synthesis of the first generation of ligands. The chirality of this second generation ligand was installed by a Sharpless asymmetric dihydroxylation reaction (90% ee). The subsequently elaborated 2,2'-bipyridyl ligand (enriched to>99% ee) was then evaluated in copper(1)-catalyzed asymmetric cyclopropanation reactions of alkenes and diazoesters. In the case of the reaction of para-fluorostyrene and tert-butyl diazoacetate, the corresponding cyclopropane was formed in good diastereoselectivity (92:8) and in excellent enantioselectivity (99% ee). This ligand was also evaluated in copper(I1)-catalyzed asymmetric Friedel-Crafts alkylation reactions of various substituted indoles (up to 90% ee) and in copper(1)- catalyzed asymmetric allylic oxidation reactions of cyclic alkenes with tert-butyl peroxybenzoate (up to 9 1 % ee).

Download or read book Synthetic and Mechanistic Studies of Transition Metal Mediated Carbon Nitrogen Bond Forming Reactions written by Alexandra Eve Strom and published by . This book was released on 2015 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following dissertation discusses reactions for the formation of carbon-nitrogen bonds mediated by organotransition metal reagents and catalysts. Chapter 1 presents a synthetic method for the formal hydroamination of unactivated alkenes to form anti-Markovnikov primary and secondary amine products. This transformation is accomplished through the hydrozirconation and subsequent amination of alkenes. The method is then applied to the reaction of complex molecules to emphasize the functional group tolerance of these reactions. Chapter 2 of this thesis comprises the synthesis and evaluation of a series of rhodium-phosphine hydroamination catalysts. These complexes are evaluated in a series of catalytic intramolecular Markovnikov hydroamination reactions. The mechanism of hydroamination catalyzed by the rhodium(I) complexes in this study was examined computationally, and the turnover-limiting step was elucidated. The difference in reactivity of electron-rich and electron-poor catalysts was compared to the computational results of a computational ligand screen, and it was found that the computational analysis of reaction intermediates overestimated the reactivity of electron-poor catalysts. The analysis of the catalysts in this study was expanded to include the binding preference of each ligand, compared to the unsubstituted ligand, which corrects for the disparity between observed reactivity and the calculated overall reaction barrier for electron-poor ligands. The ligand-binding preferences for new ligand structures were calculated, and it was found that ligands that were predicted to bind strongly to rhodium had improved reactivity in catalytic reactions. Chapter 3 discusses the mechanistic study of the palladium-catalyzed aminocarbonylation of aryl halides with ammonia and CO to form primary benzamides. Conditions for reactions of aryl bromides, chlorides, and iodides are described, and the mechanism of reactions of aryl bromides was studied. The kinetic order in the concentration of aryl bromide was found to be first order, and the order in the pressure of CO was found to be inverse first order. These studies were complemented by DFT calculations on the mechanism of oxidative addition of aryl bromides. The products of oxidative addition, aroyl bromide palladium intermediates, were reacted with ammonia in the presence of additives to gain insight into the mechanism of release of product. The overall dependence on the rate of the catalytic reaction was found to be insensitive to excess ammonia, indicating that the overall turnover-limiting step of the reaction is during the oxidative addition step.

Download or read book Synthesis and Structure of Novel Transition Metal Organometallic Complexes written by Dawood Afzal and published by . This book was released on 1985 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Synthesis of Chiral Ligands and Their Applications in Transition Metal catalyzed Asymmetric Reactions written by Wei Li and published by . This book was released on 2012 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of a Novel Cis decalin Ligand Scaffold and Application of Boron mediated Reactions to Asymmetric Ligand Evaluation written by Jason W. Skudlarek and published by . This book was released on 2000 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Novel Polydentate Ligands and Transition Metal Chalcogenolates written by Nandakumar Govindaswamy and published by . This book was released on 1995 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rational Design of New Chiral Ligands for Transition Metal catalyzed Asymmetric Synthesis written by David John O'Neill and published by . This book was released on 1999 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: