Download or read book Domino Reactions Asymmetric Palladium II catalyzed Cyclizations carbonylations in the Synthesis of Natural Compounds written by Jana Dohanosova and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intramolecular Wacker-type cyclization of unsaturated polyols and aminopolyols represents a powerful method in the synthesis of oxygen- or nitrogen-containing heterocycles. The thesis offers an insight into the systematic study of domino intramolecular palladium(II)-catalyzed cyclization and coupling reaction allowing the implementation of side chains into heterocyclic skeletons along with the formation of two stereocenters in a single step. Different types of coupling partners and reaction conditions were examined, the influence of substrate substituents on diastereoselectivity is discussed. The applications in the synthesis of naturally occuring compounds or their analogs are outlined (anisomycin, varitriol). Palladium(II)-catalyzed oxycarbonylation represents an interesting transformation of unsaturated polyols into bicyclic lactones with tetrahydrofuran structural motif with excellent cis-stereoselectivity. The first example of the use of ionic liquids as reaction media in the asymmetric Pd(II)-catalyzed oxycarbonylation is described. Based on a ligand screening, the chiral bis(oxazoline)-type ligands were successfully used in the Pd(II)-promoted bicyclisationof racemic pent-4-ene-1,3-diol (±)-69a. The kinetic resolution of (±)-69a in the presenceof chiral catalyst and p-benzoquinone under carbon monoxide atmosphere using acetic acid and/or ionic liquid as solvent afforded enantioenriched 2,6-dioxabicyclo[3.3.0]octane-3-ones(R,R)-70a (57% ee) and (S,S)-70a (80% ee), respectively.

Download or read book Asymmetric Domino Reactions written by Helene Pellissier and published by Royal Society of Chemistry. This book was released on 2013-03-13 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the latest developments in asymmetric domino reactions, focussing on those published in the last 6 years. These fascinating reactions have rapidly become one of the most current fields in organic chemistry, since they allow reaching easily high molecular complexity in an economically favourable way with advantages of savings in solvent, time, energy, and costs. Unsurprisingly, the high levels of efficiency and enantioselectivity generally reached in these reactions have been exploited for the production of a wide number of complex chiral molecules with dense stereochemistry and functionality, which are motifs present in biologically active compounds and natural products. The book is divided into three principal sections, dealing successively with asymmetric domino reactions based on the use of chiral auxiliaries, asymmetric domino reactions based on the use of chiral metal catalysts, and asymmetric domino reactions based on the use of chiral organocatalysts, covering the literature since the beginning of 2006.

Download or read book Palladium in Organic Synthesis written by Jiro Tsuji and published by Springer. This book was released on 2010-11-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Palladium is a remarkable metal. In particular, organopalladium chemistry has made remarkable progress over the last 30 years. That progress is still continuing, without any end in sight. This book presents a number of accounts and reviews on the novel Pd-catalyzed reactions discovered mainly in the last five years. The book covers Pd-catalyzed reactions that are new – entirely different from the more standard ones. Topics such as new reactions involving ß-carbon elimination and formation of palladacycles as key reactions, cross-coupling of unactivated alkyl electrophiles with organometallic compounds, arylation via C-H bond cleavage, Pd/norbornene-catalyzed aromatic functionalizations, three-component cyclizations of allenes, use of N-heterocyclic carbenes as ligands, asymmetric reactions catalyzed by Pd(II) compounds such as Lewis acids, cycloadditions of arynes and alkynes, and nucleophilic attack by Pd species are surveyed in detail by researchers who have made important contributions to these fields. The book addresses graduate students majoring in organic synthesis and researchers in academic and industrial institutes.

Download or read book Handbook of Organopalladium Chemistry for Organic Synthesis written by Ei-ichi Negishi and published by John Wiley & Sons. This book was released on 2003-11-24 with total page 1657 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organized to provide maximum utility to the bench synthetic chemist. The editor is well-known for his work in exploring, developing, and applying organopalladium chemistry. Contributors include over 24 world authorities in the field.

Download or read book Palladium Catalyzed Domino Reactions on Carbohydrates and Dialkynes written by Markus Leibeling and published by . This book was released on 2013-07-09 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Palladium Assisted Synthesis of Heterocycles written by Navjeet Kaur and published by CRC Press. This book was released on 2019-05-01 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a compilation of the recent applications of palladium catalysts in organic synthesis. The book demonstrates that it is a highly dynamic research field. This methodology has emerged as a powerful tool for the efficient and chemoselective synthesis of heterocyclic molecules. In the past few years, several strategies have been pointed out to pursue more efficient, sustainable, and environment friendly chemical processes. Among those strategies, catalysis and the design of new processes that avoid the use of toxic reagents have been the focus of intense research.

Download or read book Palladium Catalyzed Oxidative Cascade Cyclizations Via C N C C Formation for Synthesis of Nitrogen Heterocycles written by Wei Du and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Palladium-catalyzed oxidative cascade cyclizations via C-N/C-C formation for synthesis of nitrogen heterocycles" by Wei, Du, 杜玮, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled PALLADIUM-CATALYZED OXIDATIVE CASCADE CYCLIZATIONS VIA C-N/C-C FORMATION FOR SYNTHESIS OF NITROGEN HETEROCYCLES submitted by Du Wei for the Degree of Doctor of Philosophy at The University of Hong Kong in May 2014 Pd(II)-catalyzed oxidative amination of alkenes is a versatile method to construct N-containing heterocycles which are found in many biologically active synthetic targets, including natural products and pharmaceuticals. Considering the efficiency of the cascade reaction, we have employed this protocol to synthesize nitrogen heterocycles (including chiral ones) via Pd(II)-catalyzed C-N/C-C bond formation. We have developed a highly efficient enantioselective method for oxidative cascade cyclization of acrylamides tethered alkene using Pd(TFA) /diPh-pyrox as catalyst under a mild aerobic condition (Scheme 1). A series of pyrrolizidine derivatives, such as 2.4a, 2.2h, and 2.2n, have been synthesized in good yields and excellent enantioselectivity. The mechanism study has indicated that the cyclization reaction proceeded through both trans-/cis-aminopalladation (AP) with a ratio of ca. 3:1 (Scheme 2). Besides, we have found that some factors, including the counterions of Pd(II) complexes, the electronic density of the isolated double bond and the steric bulkiness of ligands, affect the stereochemical selectivity in the aminopalladation step. This study has important implications for designing new catalyst systems for enantioselective Pd-catalyzed oxidative amination reactions. We have also disclosed the first enantioselective Pd(II)-catalyzed oxidative aminoarylation reaction (Scheme 3). The reactions were carried out with Pd(OAc) /β-ICD as catalyst to synthesize indoline derivatives, such as 3.2a, 3.2b and 3.2i, in moderate to good yields with moderate enantioselectivity. Base on previous successful cascade reactions of aminopalladation/C(sp )-H functionalization, we have developed a palladium (II)-catalyzed oxidative cascade aminoalkylation via aminopalladation/C(sp )-H activation for divergent synthesis of three-membered-ring (i.e. 4.2ag, 4.2an and 4.2ar) or five-membered-ring (i.e. 4.3aa, 4.3ad and 4.3bs) fused indolines (Scheme 4). The benzylic C-H and the C-H at -position of anilides can be selectively activated under different reaction conditions. 3 This is the first example of palladium catalyzed C(sp )-H activation without employment of prefunctionalized reagents (halogenated or boron-containing reagents) and directing groups, representing a green and economic protocol for construction of N-containing heterocycles. Scheme 1 Scheme 2 Scheme 3 Scheme 4 DOI: 10.5353/th_b5312312 Subjects: Heterocyclic compounds - Synthesis Organopalladium compounds

Download or read book Asymmetric Synthesis of Drugs and Natural Products written by Ahindra Nag and published by CRC Press. This book was released on 2018-01-12 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on different techniques of asymmetric synthesis of important compounds, such as drugs and natural products. It gives insightful information on recent asymmetric synthesis by Inorganic, Organic and Enzymatic combinations. It also emphasizes chiral compounds and design of new catalyst for synthesis of compounds.

Download or read book Rhodium Catalysis written by Carmen Claver and published by Springer. This book was released on 2017-12-15 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics of pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors. All chapters from Topics in Organometallic Chemistry are published OnlineFirst with an individual DOI. In references, Topics in Organometallic Chemistry is abbrev iated as Top Organomet Chem and cited as a journal.

Download or read book The Mizoroki Heck Reaction written by Martin Oestreich and published by John Wiley & Sons. This book was released on 2009-02-11 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the importance of Richard F. Heck’s carbon coupling reaction, this book highlights the subject of the 2010 Nobel Prize in Chemistry for palladium-catalyzed cross couplings in organic synthesis, and includes a foreword from Nobel Prize winner Richard F. Heck. The Mizoroki-Heck reaction is a palladium-catalyzed carbon–carbon bond forming process which is widely used in organic and organometallic synthesis. It has seen increasing use in the past decade as chemists look for strategies enabling the controlled construction of complex carbon skeletons. The Mizoroki-Heck Reaction is the first dedicated volume on this important reaction, including topics on: mechanisms of the Mizoroki-Heck reaction intermolecular Mizoroki-Heck reactions focus on regioselectivity and product outcome in organic synthesis waste-minimized Mizoroki-Heck reactions intramolecular Mizoroki-Heck reactions formation of heterocycles chelation-controlled Mizoroki-Heck reactions the Mizoroki-Heck reaction in domino processes oxidative heck-type reactions (Fujiwara-Moritani reactions) Mizoroki-Heck reactions with metals other than palladium ligand design for intermolecular asymmetric Mizoroki-Heck reactions intramolecular enantioselective Mizoroki-Heck reactions desymmetrizing Mizoroki-Heck reactions applications in combinatorial and solid phase syntheses, and the development of modern solvent systems and reaction techniques the asymmetric intramolecular Mizoroki-Heck reaction in natural product total synthesis Several chapters are devoted to asymmetric Heck reactions with particular focus on the construction of otherwise difficult-to-obtain sterically congested tertiary and quaternary carbons. Industrial and academic applications are highlighted in the final section. The Mizoroki-Heck Reaction will find a place on the bookshelves of any organic or organometallic chemist. “I am convinced that this book will rapidly become the most important reference text for research chemists in academia and industry who seek orientation in the rapidly growing and – for the layman – confusing field described as the “’Mizoroki–Heck reaction’.” (Synthesis, March 2010)

Download or read book Organic Synthesis with Palladium Compounds written by Jiro Tsuji and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Around 30 years ago the transition metal chemistry received great impulses. In the focus have been reactions of nickel and cobalt and herein especially their carbonyls. Also industrial processes have been developed. When the technical oxidation of ethylene with palladium chloride had been discovered, and a great number oflaboratory reactions, many groups have turned towards this subject. Apart from two important industrial processes - acetaldehyde and vinylacetate from ethylene - a great number of conversions and catalytic reactions with palladium compounds have been researched. Their mechanisms have been cleared up and have con tributed to a better understanding of the complex chemistry of palladium. Last but not least these reactions have also served for more understanding of organic transition metal compounds and catalyses in general. Numerous conventional reactions appear today in a different light. The effects of co-

Download or read book Rhodium and Palladium Catalyzed Organic Transformations in the Synthesis of Small Heterocyclic Compounds written by Jennifer Chia-Fang Tsoung and published by . This book was released on 2015 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rhodium Catalyzed Hydroformylation written by Piet W.N.M. van Leeuwen and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decade there have been numerous advances in the area of rhodium-catalyzed hydroformylation, such as highly selective catalysts of industrial importance, new insights into mechanisms of the reaction, very selective asymmetric catalysts, in situ characterization and application to organic synthesis. The views on hydroformylation which still prevail in the current textbooks have become obsolete in several respects. Therefore, it was felt timely to collect these advances in a book. The book contains a series of chapters discussing several rhodium systems arranged according to ligand type, including asymmetric ligands, a chapter on applications in organic chemistry, a chapter on modern processes and separations, and a chapter on catalyst preparation and laboratory techniques. This book concentrates on highlights, rather than a concise review mentioning all articles in just one line. The book aims at an audience of advanced students, experts in the field, and scientists from related fields. The didactic approach also makes it useful as a guide for an advanced course.

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 Synthetic Endeavours in Nitrogen Heterocycles written by Charles Hamilton Heath and published by . This book was released on 2011 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes our synthetic endeavours in nitrogen containing heterocyclic compounds. The work included several key themes including the pursuit of biologically active compounds, the development of elegant and environmentally benign procedures including domino reactions. The use of palladium mediated transformations in organic synthesis, the construction of new unknown ring systems and the structural elucidation of heterocyclic compounds including the structural elucidation of natural products by synthesis have also been explored. Chapter 2 describes our synthetic investigations of the 3-benzazepines I and azepino[4,5-b]indoles II. Through the use of the palladium catalysed Tsuji-Trost reaction followed by a Heck reaction we were able to devise a synthetic approach to access these N-heterocycles. We were able to synthesize simple derivatives of both I and II in addition to more complex compounds featuring additional fused rings by including the use of different cyclic and acyclic allylic substrates for the Tsuji-Trost reaction. After the development of the single step Tsuji-Trost/Heck synthetic protocols for these compounds we successfully combined these two reactions into a single pot domino reaction. In addition to Tsuji-Trost/Heck domino reactions we have also developed a Heck/carbopalladation domino reaction for the synthesis of an azepino[3,4,5-hi]benz[b]indolizine derivative. Chapter 3 describes our attempts to synthesize the natural product arboflorine. We initially began with attempts to elaborate the azepino[4,5-b]indoles synthesized in Chapter 2 to provide arboflorine, however this did not prove fruitful. In the course of this investigation we discovered a novel rearrangement of an azepino[4,5-b]indole to give the peroxide IV which became the topic of Chapter 4. We attempted to further elaborate other known azepino[4,5-b]indoles via a variety of methods including inter and intramolecular Heck reactions, radical chain reactions and functionalization via an iminium salt. These attempts were also unsuccessful. Finally we chose to modify the synthesis of a simpler, related tetracycle for the synthesis of arboflorine, developed by Bosch and Passarella. Following their general synthetic strategy we were able to synthesize a key nitrile intermediate to the synthesis of arboflorine. The cyclization of this nitrile was attempted but was not successful under a series of reaction conditions. Chapter 4 describes the structural elucidation of the peroxide IV. A possible mechanistic explanation for the formation of the peroxide is given and this is discussed in the context of relevant literature examples. The formation of the peroxide IV led to our increased interest in the general reactivity of the azepino[4,5-b]indoles and several simple reactions were carried out in the hope of discovering further novel rearrangements.

Download or read book Total Synthesis of Natural Products written by Jie Jack Li and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Total Synthesis of Natural Products' is written and edited by some of today's leaders in organic chemistry. Eleven chapters cover a range of natural products, from steroids to alkaloids. Each chapter contains an introduction to the natural product in question, descriptions of its biological and pharmacological properties and outlines of total synthesis procedures already carried out. Particular emphasis is placed on novel methodologies developed by the respective authors and their research groups. This text is ideal for graduate and advanced undergraduate students, as well as organic chemists in academia and industry.

Download or read book The Development of Palladium and Copper catalyzed Transformations for the Asymmetric Synthesis of Biologically Active Small Molecules written by James Thomas Masters and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The continued demand for efficient chemo-, regio-, and stereoselective organic transformations motivates the development of new chemical reactions. Transition metal catalysis represents a powerful method for the construction of carbon-carbon, carbon-hydrogen, and carbon-heteroatom bonds in a highly selective fashion. This dissertation describes the development of several new transition metal-catalyzed organic reactions useful in the preparation of various chiral small molecules, including both fundamental organic "building block" compounds and structurally complex natural products and pharmaceutical agents. We report a new strategy for the synthesis of chiral beta-alkynyl esters, ketones, and sulfones via sequential palladium-catalyzed carbon-carbon bond formation and copper-catalyzed carbon-hydrogen bond formation. The process is operationally straightforward, compatible with a broad range of substrates, and delivers the targets in high yields with excellent levels of enantioselectivity. It is compatible with both oxygen and nitrogen functionality, and this enabled the rapid elaboration of the products into a diverse set of chiral heterocycles. The sequential catalysis protocol was employed in a concise, enantioselective synthesis of AMG 837, a potent agonist of G-protein coupled receptor 40. Recognizing both the biological relevance of chiral alkaloids and the synthetic challenges associated with the construction of quaternary, all-carbon stereocenters, we pursued a palladium-catalyzed asymmetric allylic alkylation that effected carbon-carbon bond formation on prochiral oxindole nucleophiles. Although prior research has demonstrated that allylic alkylation reactions of geminal dicarboxylate electrophiles typically yield branched products as the result of ipso-addition, we identify conditions wherein oxindoles react with a dipivaloyl electrophile to afford linear enol pivalate compounds. A mild hydrolysis reaction converts these products into the aldehyde that formally results from asymmetric conjugate addition to acrolein, a challenging transformation with limited literature precedent. These adducts are established precursors to tricyclic alkaloid scaffolds of pharmaceutical interest. Chiral gamma-heteroatom-substituted cycloalkenones are well-established organic "building blocks" that are widely used in the synthesis of complex molecules. The exposure of meso-1,4-allylic dibenzoates to chiral phosphine-ligated palladium salts in the presence of a potassium nitronate nucleophile promotes a unique oxidative desymmetrization reaction. This process yields enantiopure gamma-benzoyloxy cyclopentenones, cyclohexenones, and cycloheptenones. We describe the elaboration of these products into diverse, enantioenriched oxygen- and nitrogen-substituted cycloalkenones via subsequent palladium-catalyzed allylic alkylation reactions involving heteroatom nucleophiles. Separately, we employ enantiopure gamma-benzoyloxy cyclohexenones in short, asymmetric syntheses of enantio- and diastereomerically diverse epoxyquinoid natural products. We further highlight the utility of palladium catalysis in complex molecule synthesis through the development of a unique, intramolecular carbon-carbon bond-forming reaction that generates a strained enyne and through an asymmetric formal synthesis of aliskiren, a renin inhibitor used in the treatment of hypertension.