Download or read book Net 3 2 type Heterocyclic Synthesis Via Organostannanes and Palladium Chemistry written by Peter Joseph Bonk and published by . This book was released on 1985 with total page 852 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 432 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 and Nickel Catalyzed Transformations Forming Functionalized Heterocycles written by Hyung Yoon and published by Springer Nature. This book was released on 2020-09-02 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents Pd- and Ni-catalyzed transformations generating functionalized heterocycles. Transition metal catalysis is at the forefront of synthetic organic chemistry since it offers new and powerful methods to forge carbon–carbon bonds in high atom- and step-economy. In Chapter 1, the author describes a Pd- and Ni-catalyzed cycloisomerization of aryl iodides to alkyl iodides, known as carboiodination. In the context of the Pd-catalyzed variant, the chapter explores the production of enantioenriched carboxamides through diastereoselective Pd-catalyzed carboiodination. It then discusses Ni-catalyzed reactions to generate oxindoles and an enantioselective variant employing a dual ligand system. Chapter 2 introduces readers to a Pd-catalyzed diastereoselective anion-capture cascade. It also examines diastereoselective Pd-catalyzed aryl cyanation to synthesize alkyl nitriles, a method that generates high yields of borylated chromans as a single diastereomer, and highlights its synthetic utility. Lastly, Chapter 3 presents a Pd-catalyzed domino process harnessing carbopalladation, C–H activation and π-system insertion (benzynes and alkynes) to generate spirocycles. It also describes the mechanistic studies performed on these reactions.

Download or read book Copper Catalyzed Multi Component Reactions written by Yusuke Ohta and published by Springer Science & Business Media. This book was released on 2011-01-20 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: A copper-catalyzed direct synthesis of 2-(aminomethyl)indoles by catalytic domino reaction including multi-component coupling was developed, and is the first example of a three-component indole formation without producing salts as a byproduct. Based on this reaction, a copper-catalyzed synthesis of 3-(aminomethyl)isoquinoline was accomplished which represents an unprecedented isoquinoline synthesis through a four-component coupling reaction. Following these results, extensive application studies using one-pot palladium-, acid-, or base-promoted cyclization revealed that indole- or isoquinoline-fused polycyclic compounds can be readily synthesized through multi-component reactions. As the concept of Green Chemistry becomes ever more important, these findings may provide efficient and atom-economical approaches to the diversity-oriented synthesis of bioactive compounds containing a complex structure. This could lead to development of promising drug leads with structural complexity. The work of this thesis will go on to inspire the synthetic research of many readers.

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 Noble Metal Noble Value written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Heterocyclic chemistry constitutes the largest branch of chemistry, covering almost two-thirds of literature in the field. In addition, around 90% of naturally-occurring molecules have heterocycles as their core structure. Therefore, as a central part of organic chemistry, the discovery of new methodologies in synthesizing heterocyclic compounds is essential to their continued application and development. Transition metal catalysts offer a low cost and often low toxicity pathway for heterocycles synthesis, while the use of noble metals represents an alternative form of experimentation which is discussed in the book. Noble Metals, Noble Value provides the first comprehensive analysis of the applications of the noble metals of ruthenium (Ru), rhodium (Rh) and palladium (Pd) catalysts in heterocycles synthesis. Pairs of chapters are dedicated to summarizing each of the metals when applied to either five- or six-membered heterocyclic syntheses. An introduction to the importance of heterocycles and possible procedures for the preparation of heterocyclic compounds is also given. With up to date research and findings, this review is excellently suited to academics and professionals in the field of chemistry, with a particular focus on the specialities of biological, catalytic and organic chemistry."--

Download or read book Synthesis of Heterocycles and Biaryls Via Anion accelerated Palladium mediated Coupling Reactions written by Del David Hennings and published by . This book was released on 1997 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Palladium and Electrophilic Cyclization Approaches to Carbo and Heterocyclic Compounds written by Dawei Yue and published by . This book was released on 2004 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation the scope and limitations of several electrophilic cyclization processes have been presented. In particular, electrophilic cyclization has been used for the synthesis of a variety of heterocycles, including benzo[b]furans, isochromenes, dihydroisoquinolines, isobenzofurans and coumestans. An unusual palladium migration has also been explored and applied to the synthesis of fluoren-9-ones. Chapter 1 describes the synthesis of 2,3-disubstituted benzo[b]furans by the palladium-catalyzed coupling and electrophilic cyclization of terminal alkynes. A highly chemoselective electrophilic cyclization has been achieved by carefully choosing the protecting group on the oxygen functionality. Various electrophiles, such as I2, Br2, PhSeCl and p-O2NC6H4SCl, can be used to introduce different functionalities into the desired cyclization products. Chapter 2 presents the synthesis of heterocycles by electrophilic cyclization reactions of acetylenic aldehydes, ketones and imines. The overall synthetic process involves the coupling of a terminal acetylene with o-iodoarenecarboxaldehydes or ketones by a palladium-catalyzed coupling reaction, followed by electrophilic cyclization with various electrophiles in the presence of proper nucleophiles. Oxygen- and nitrogen-containing heterocycles can be quickly assembled by this three component process in good to excellent yields. Chaper 3 describes the synthesis of coumestan and coumestrol by selective electrophilic cyclization, followed by palladium-catalyzed intramolecular carbonylation and lactonization. The biologically interesting coumestan system can be quickly constructed by this very efficient approach from common starting materials. The palladium-catalyzed reaction effects as both carbonylation and lactonization in one step. Chapter 4 examines the scope and synthetic utility of a 1,4-Pd through space migration. The synthesis of various fluoren-9-ones has been accomplished by the Pd-catalyzed intramolecular C-H activation of imines derived from 2-iodoaniline and biarylcarboxaldehydes. This methodology makes use of a novel 1,4-palladium migration from an aryl position to an imidoyl position to generate the key imidoyl palladium intermediate, which undergoes intramolecular arylation to produce imines of complex polycyclic compounds containing the fluoren-9-one core structure. Both electronic effects and steric effects have been investigated.

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1985 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Synthesis of Heterocycles Via Palladium catalyzed Carbonylative Annulation of Internal and Terminal Alkynes written by Dmitry Valerievich Kadnikov and published by . This book was released on 2002 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this dissertation is the study of palladium-catalyzed reactions of internal and terminal alkynes with ortho-substituted aryl iodides such as, o-iodophenols and N-substituted o-iodoanilines, in the presence of carbon monoxide (carbonylative annulation). The exploration of these reactions have led to the development of efficient syntheses of the important heterocycles coumarins and 2-quinolones. 3,4-Disubstituted coumarins are efficiently synthesized by the palladium-catalyzed annulation of internal alkynes by o-iodophenols in the presence of just one atmosphere of carbon monoxide. The use of a sterically unhindered pyridine base is essential to achieve high yields. The reaction accommodates a number of organic functional groups both on the alkyne and the o-iodophenol, thus affording a wide variety of coumarins in moderate to good yields. The main disadvantage of the process is formation of mixtures of regioisomers in reactions employing unsymmetrical alkynes. The use of N-substituted o-iodoanilines as annulating agents provides an efficient synthesis of 3,4-disubstituted 2-quinolones. In this process, the selection of the nitrogen protecting group is crucial for the success of the reaction. The best results are obtained utilizing alkyl carbamates, tosylamides and trifluoroacetamides. The major features of this process are similar to those of the coumarin synthesis. These annulation processes are the first examples of the insertion of an alkyne into the arylpalladium bond occurring in preference to the insertion of CO. We have shown that the unusual order of insertion arises from the low reactivity of the initially formed acylpalladium complex towards internal alkynes. Utilizing the reaction conditions developed for the carbonylative annulation of internal alkynes we have been able to affect the carbonylative annulation of terminal alkynes by o-iodophenols or o-iodoaniline derivatives to afford coumarins or 2-quinolones, respectively, in modest yields. The formation of coumarins and 2-quinolones in this process is in stark contrast with all previously described palladium-catalyzed carbonylative annulation of terminal alkynes, which have afforded chromones and 4-quinolones. Moreover, under our reaction conditions terminal alkynes insert into the carbon-palladium bond instead of undergoing a Sonogashira-type coupling. This reaction pathway is confirmed by an isotope labeling experiment.

Download or read book Synthesis of Heterocycles written by Chun Lu and published by . This book was released on 2010 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of 2 3 diaryl 4 methoxyquinolines Via Palladium catalyzed Cross Coupling Reactions written by Vathiswa Mtshemla and published by . This book was released on 2008 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1986 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Stille Reaction written by Vittorio Farina and published by John Wiley & Sons. This book was released on 1998-09-18 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Die Stille-Reaktion ist eine der sehr wenigen Reaktionen, in denen unter milden Bedingungen Kohlenstoff-Kohlenstoff-Bindungen geknüpft werden können. Man verwendet die Reaktion häufig in der Synthese komplizierter Moleküle zur Verknüpfung größerer Molekülbausteine. Die Autoren diskutieren vom präparativen Standpunkt aus Grenzen, Einflüsse, strukturelle Effekte und die Wahl der geeigneten Reaktionsbedingungen. Mit ausführlichen Vorschriften und vielen Beispielen. (11/98)

Download or read book Cross Coupling Reactions written by Norio Miyaura and published by Springer. This book was released on 2003-07-01 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1972, a very powerful catalytic cycle for carbon-carbon bond formation was 2 first discovered by the coupling reaction of Grignard reagents at the sp -carbon. Over the past 30 years, the protocol has been substantially improved and expanded to other coupling reactions of Li,B,N,O,Al,Si,P,S,Cu,Mn,Zn,In,Sn, and Hg compounds. These reactions provided an indispensable and simple methodology for preparative organic chemists. Due to the simplicity and rel- bility in the carbon-carbon, carbon-heteroatom, and carbon-metalloid bo- formations,as well as high efficiency of the catalytic process,the reactions have been widely employed by organic chemists in various fields. Application of the protocol ranges from various syntheses of complex natural products to the preparation of biologically relevant molecules including drugs, and of sup- molecules, and to functional materials. The reactions on solid surfaces allow robot synthesis and combinatorial synthesis. Now, many organic chemists do not hesitate to use transition metal complexes for the transformation of org- ic molecules. Indeed, innumerable organic syntheses have been realized by the catalyzed reactions of transition metal complexes that are not achievable by t- ditional synthetic methods. Among these, the metal-catalyzed cross-coupling reactions have undoubtedly contributed greatly to the development of such a new area of “metal-catalyzed organic syntheses”. An excellent monograph for the cross-coupling reactions and other met- catalyzed C-C bond-forming reactions recently appeared in Metal-catalyzed Cross-coupling Reactions (Wiley-VCH,1998).

Download or read book Applied Cross Coupling Reactions written by Yasushi Nishihara and published by Springer Science & Business Media. This book was released on 2012-12-14 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Applied Cross-Coupling Reactions” provides students and teachers of advanced organic chemistry with an overview of the history, mechanisms and applications of cross-coupling reactions. Since the discovery of the transition-metal-catalyzed cross-coupling reactions in 1972, numerous synthetic uses and industrial applications have been developed. The mechanistic studies of the cross-coupling reactions have disclosed that three fundamental reactions: oxidative addition, transmetalation, and reductive elimination, are involved in a catalytic cycle. Cross-coupling reactions have allowed us to produce a variety of compounds for industrial purposes, such as natural products, pharmaceuticals, liquid crystals and conjugate polymers for use in electronic devices. Indeed, the Nobel Prize for Chemistry in 2010 was awarded for work on cross-coupling reactions. In this book, the recent trends in cross-coupling reactions are also introduced from the point of view of synthesis design and catalytic activities of transition-metal catalysts.