Download or read book Formation of Novel Carbocycles and Heterocycles Via Palladium Catalysis written by Liangqin Guo and published by . This book was released on 1994 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Palladium catalyzed Approaches to Heterocycles and Carbocycles written by Qinhua Huang and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The tert-butylimines of o-(1-alkynyl)benzaldehydes and analogous pyridinecarbaldehydes have been cyclized under very mild reaction conditions in the presence of I2, ICl, PhSeCl, and p-O2NC6H4SCl to give the corresponding halogen-, selenium-, and sulfur containing disubstituted isoquinolines and naphthyridines, respectively. Monosubstituted isoquinolines and naphthyridines have been synthesized by the metal-catalyzed ring closure of these same iminoalkynes. The Pd(II)-catalyzed cyclization of 2-(1-alkynyl)arylaldimines in the presence of various alkenes provides an efficient way to synthesize a variety of 4-(1-alkenyl)-3-arylisoquinolines in moderate to excellent yields. The introduction of an ortho-methoxy group on the arylaldimine promotes the Pd-catalyzed cyclization and stabilizes the resulting Pd(II) intermediate, improving the yields of the isoquinoline products. Highly substituted naphthalenes have been synthesized by the palladium-catalyzed annulation of a variety of internal alkynes, in which two new carbon-carbon bonds are formed in a single step under relatively mild reaction conditions. This method has also been used to synthesize carbazoles, although a higher reaction temperature is necessary. This method accommodates a variety of functional groups and affords the anticipated highly substituted naphthalenes and carbazoles in good to excellent yields. Novel palladium migration/arylation methodology for the synthesis of complex fused polycycles has been developed, in which one or more sequential Pd-catalyzed intramolecular migration processes involving C-H activation are employed. The chemistry works best with electron-rich aromatics, which is in agreement with the idea that these palladium-catalyzed C-H activation reactions parallel electrophilic aromatic substitution. A relatively efficient synthesis of cyclopropanes has been developed using palladium-catalyzed C-H activation chemistry, in which two new carbon-carbon bonds are formed in a single step. This method involves the palladium-catalyzed activation of relatively unreactive C-H bonds, and provides a very efficient way to synthesize cyclopropapyrrolo[1,2-a]indoles, analogues of the mitomycin antibiotics.

Download or read book Synthesis of Heterocycles and Carbocycles Through Tandem and Domino Palladium catalyzed Reactions written by David Ingoo Chai and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Palladium in Heterocyclic Chemistry written by Jie Jack Li and published by Elsevier. This book was released on 2000 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: For this text, Jack Li and Gordon Gribble have compiled an array of referenced examples of the use of palladium in heterocyclic chemistry.

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 Open Dissertation Press. 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 The Synthesis of Heterocycles Via Palladium Catalysis written by Paul Aidan Stoker and published by . This book was released on 2008 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Palladium catalyzed Approaches to Heterocycles and Carbocycles written by Guangxiu Dai and published by . This book was released on 2003 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wide variety of 3,4-disubstituted isoquinolines containing an aryl, allylic, benzylic, alkynyl and vinylic group at the 4 position have been prepared via cross-coupling of 2-(1-alkynyl)benzaldimines with organic halides in the presence of a palladium catalyst. The best results are obtained by employing 5 mol % Pd(PPh3)4, 5 equiv of K2CO3 in DMF at 100°C. The electronic effect of the imine substrates and organic halides on the yields has been discussed. 3-Substituted 4-aroylisoquinolines have been prepared in high yields via carbonylative cross-coupling of 2-(1-alkynyl)benzaldimines with aromatic iodides or aroyl chlorides in the presence of a palladium catalyst under 1 atm of CO pressure. Imine substrates having an aryl, vinylic or alkyl substituent on the distal end of the triple bond all undergo this palladium-catalyzed carbonylative cross-coupling cyclization in high yields. The palladium(II)-catalyzed oxidative carbonylation of 2-(1-alkynyl)benzaldimines for synthesis of the corresponding isoquinoline-4-carboxylates has been studied and the optimal reaction conditions have been investigated. Although this methodology study has not provided an efficient route to synthesize methyl 3-substituted isoquinoline-4-carboxylates in synthetically useful yields, it provides an insight into the nature of the palladium-catalyzed cyclization reactions promoted by organopalladium intermediates. A novel intramolecular alkyl-to-aryl palladium rearrangement has been observed by trapping the arylpalladium intermediate with an olefin by a Heck reaction. The reaction conditions have been optimized and the reaction scope has been extensively studied. In all of the successful examples, migration products were isolated exclusively. In addition, this alkyl-to-aryl palladium migration can be controlled by simply modifying the reaction conditions.

Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 39 (thesis year 1994) a total of 13,953 thesis titles from 21 Canadian and 159 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 39 reports theses submitted in 1994, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.

Download or read book Nickel and Palladium Catalyzed Routes to Carbocycles and Heterocycles written by Ashish Thakur and published by . This book was released on 2015 with total page 182 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 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 Synthesis and Elaboration of Heterocycles Via Palladium catalyzed C H Functionalization written by Maria Gerelle and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 is a brief literature review of the most recent progress in the area of C-H functionalization via palladium catalysis. This covers the functionalization of electron deficient arenes and heterocycles with alkenyl and alkyl halides both using inter- and intra-molecular reactions. The chapter also contains an overview of recent work from the Willis group. Chapter 2 presents the functionalization of electron deficient arenes and alkenyl bromides using palladium catalysis (Scheme 1), as well as the use of statistical analysis software for optimizing the cross-coupling reaction. Scheme 1: Functionalization of electron deficient arenes using palladium catalysis Chapter 3 describes the cross-coupling of substituted benzoxazoles, benzothiazole and benzimidazole with a range of alkenyl iodides using palladium catalysis (Scheme 2). The reaction can tolerate both (E) and (Z) disubstituted alkenes and tri-substituted alkenyl iodides, with retention of the double bond geometry. 1 x =0, S, NMe - 14 examples 25-99% yield i Scheme 2: Cross-coupling using benzoxazoles, benzothiazole and benzimidazole with alkenyl iodides Chapter 4 details the synthesis of sultams via an intramolecular functionalization using palladium catalysis. The chapter covers the optimization of the starting material synthesis as well as the cross-coupling reaction. We can access the sulfonamides from cyc1ohexenone and were able to incorporate a large range of substitution patterns (Scheme 3). Scheme 3: Synthesis ofsultams from cyclohexenone Finally, Chapter 5 contains all the experimental details, general considerations and compound data. All the NMR spectra of novel compounds can be found in the appendix. 2.

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 New Palladium Catalyzed Carbonylative Approaches to Heterocycle and Acid Chloride Synthesis written by Gerardo Martin Torres and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Metal catalyzed carbonylation reactions are heavily exploited in synthetic chemistry. These include not only high volume industrial reactions, but also a plethora of catalytic small molecule syntheses. This thesis will describe our efforts to develop such reactions. In these, palladium catalyzed carbonylations are exploited to build-up reactive products such as acid chlorides or carbonyl-containing 1,3-dipoles. Coupling this with the ability of the products undergo other spontaneous reactions can offer new routes to build up products from combinations of available reagents or be used to expand the scope of carbonylation chemistry. In chapter 2, we describe how the palladium catalyzed carbonylation of aryl iodides in the presence of imines can allow the overall generation of a 1,3-dipole: a Münchnone. A variety of mechanistic studies were performed on this reaction and show that it proceeds via a tandem catalytic process: the first involving the Pd catalyzed coupling of aryl iodides with carbon monoxide and a chloride salt to form an acid chloride, which can react with an imine and then undergo a second spontaneous cyclocarbonylation to afford the product. Coupling their formation with alkyne cycloaddition can be used to develop a novel method to assemble broad families of pyrroles from aryl iodides, imines, carbon monoxide and alkynes. In Chapter 3 we develop a strategy to apply our palladium catalyzed carbonylative synthesis of Münchnones to construct more complex pyrrole structures. In this, the combination of alkyne-tethered imines, aryl iodides, and carbon monoxide generates a Münchnone that can undergo intramolecular 1,3-dipolar cycloaddition to generate polycyclic pyrroles. This approach allows the modular and regioselective synthesis of complex pyrrole structures, and is compatible with less activated alkynes. In addition, we show that this reaction can be used in tandem with the palladium catalyzed Sonogashira functionalization of terminal alkynes with aryl iodides.In Chapter 4 we describe our efforts to take advantage of the ketene-like reactivity of Münchnones to generate [beta]-lactams. This transformation occurs via the palladium catalyzed formation of Münchnones from imines, aryl iodides, and carbon monoxide, followed by a cycloaddition to a second equivalent of imine to afford amide substituted [beta]-lactam products. Moreover, applying the conditions described in Chapter 2 for the synthesis of Münchnones allowed us to construct more diversely substituted [beta]-lactams by reacting the Münchnone with a different imine. Alternatively, the palladium catalyzed carbonylation of imine-tethered aryl iodides leads to the formation of novel spirocyclic [beta]-lactams.The palladium catalyzed synthesis of acid chlorides is a key component to the synthetic approaches to heterocycles presented in Chapters 2-4. However, the specific features that enable the catalyst to mediate the challenging reductive elimination of acid chlorides also inhibit the reverse oxidative addition step. In Chapter 5 we address these limitations by approaching this palladium catalyzed reaction from a different perspective. In this, visible light is used to drive both key steps in palladium catalysis: oxidative addition and reductive elimination. Analogous to other reports, we show that visible light excitation of a Pd complex can drive oxidative addition of a wide variety of aryl and alkyl halides. In addition, we find that visible light can induce a new reaction step the reductive elimination of acid chlorides. The latter occurs via the excitation in this case of the palladium-acyl intermediate. Together, this offers a platform to perform palladium catalyzed carbonylations at ambient temperature, with a wide array of organic halide substrates that have proven to be challenging in traditional palladium catalysis, and form from these acid chloride electrophiles that can allow the use of nucleophiles that are typically incompatible with carbonylations"--

Download or read book Palladium in Heterocyclic Chemistry written by Jie Jack Li and published by Elsevier Science Limited. This book was released on 2007 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: A myriad of heterocycles are biologically active and therefore of paramount importance to medicinal and agricultural chemists. Many heterocycle-containing natural products (they are highlighted in boxes throughout the text) have elicited great interest from both academic and industrial research groups. Recognizing the similarities between the palladium chemistry of arenes and heteroarenes, a critical survey of the accomplishments in heterocyclic chemistry will keep readers abreast of such a fast-growing field. We also hope this book will spur more interest and inspire ideas in such an extremely useful area. This book comprises a compilation of important preparations of heteroaryl halides, boranes and stannanes for each heterocycle. The large body of data regarding palladium-mediated polymerization of heterocycles in material chemistry is not focused here; neither is coordination chemistry involving palladium and heterocycles.-

Download or read book Synthesis of Heterocycles Via Palladium catalyzed Heteroannulation of Dienes written by Norman Graciano Berríos-Penã and published by . This book was released on 1989 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Palladium catalyzed and Electrophilic Cyclization Approaches to Important Heterocycles and Carbocycles written by Saurabh Mehta and published by . This book was released on 2009 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: