Download or read book Palladium imidazolium Carbene Catalyzed Heck Coupling Reactions and Synthesis of a Novel Class of Fluoroanthracenylmethyl PTC Catalysts written by Jiuqing Zhang and published by . This book was released on 2005 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase-Transfer Catalysis (PTC) is a very useful approach and has been widely used in synthetic organic chemistry. A novel class of fluoroanthracenylmethyl PTC catalysts were synthesized and explored for asymmetric glycolate and glycine alkylation. Phosphorous pentoxide was used for the challenging electron-deficient electrophilic aromatic substitution step. These new catalysts proved to have high selectivities for glycine alkylation under mild conditions.

Download or read book Palladium Catalyzed Coupling Reactions written by Árpád Molnár and published by John Wiley & Sons. This book was released on 2013-02-14 with total page 531 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook and ready reference brings together all significant issues of practical importance in selected topics discussing recent significant achievements for interested readers in one single volume. While covering homogeneous and heterogeneous catalysis, the text is unique in focusing on such important aspects as using different reaction media, microwave techniques or catalyst recycling. It also provides a comprehensive treatment of key issues of modern-day coupling reactions having emerged and matured in recent years and emphasizes those topics that show potential for future development, such as continuous flow systems, water as a reaction medium, and catalyst immobilization, among others. With its inclusion of large-scale applications in the pharmaceutical industry, this will equally be of great interest to industrial chemists. From the contents * Palladium-Catalyzed Cross-Coupling Reactions - A General Introduction * High-turnover Heterogeneous Palladium Catalysts in Coupling Reactions: the Case of Pd Loaded on Dealuminated Y Zeolites Palladium-Catalyzed Coupling Reactions with Magnetically Separable Nanocatalysts * The Use of Ordered Porous Solids as Support Materials in Palladium-Catalyzed Cross-Coupling Reactions * Coupling Reactions Induced by Polymer-Supported Catalysts * Coupling Reactions in Ionic Liquids * Cross-Coupling Reactions in Aqueous Media * Microwave-Assisted Synthesis in C-C and C-Heteroatom Coupling Reactions * Catalyst Recycling in Palladium-Catalyzed Carbon-Carbon Coupling Reactions * Nature of the True Catalytic Species in Carbon-Carbon Coupling Reactions with * Heterogeneous Palladium Precatalysts * Coupling Reactions in Continuous Flow Systems * Large-Scale Applications of Palladium-Catalyzed Couplings in the Pharmaceutical Industry

Download or read book Master s Theses Directories written by and published by . This book was released on 2006 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Education, arts and social sciences, natural and technical sciences in the United States and Canada".

Download or read book The Mizoroki Heck Reaction written by Martin Oestreich and published by Wiley. This book was released on 2009-03-23 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 The Design of Palladium and Copper catalyzed Atom Economical Reactions written by Boran Xu and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis describes the development of novel metal-catalyzed reactions in two different areas: palladium-catalyzed multicomponent coupling reactions, and copper-catalyzed aerobic oxidations of alcohols and amines. The goal of this work is to discover efficient processes to rapidly generate useful products with minimal waste. In chapter 2, we describe a straightforward new synthesis of 2-imidazolines. This reaction couples the palladium-catalyzed multicomponent formation of 2-imidazolium carboxylates, with subsequent decarboxylation. Polysubstituted imidazolines have useful applications in therapeutics, but are typically prepared in a multistep sequence. We report that the use benzoic acid and water as additives affords good yields and diastereoselectivities for the decarboxylation step. Combining this reaction with subsequent nitrogen deprotection, allows access to imidazolines from four available reagents: two imines, an acid chloride and CO. In chapter 3, we describe the three component palladium-catalyzed synthesis of [alpha]-amidostannanes from imines, acid chlorides and a bis-stannane. The reaction affords product in good yields, proceeds in 1 h, and uses simple Pd2(dba)3 as the catalyst. Mechanistically, this transformation occurs via a Stille-type cross-coupling of an in situ generated iminium salt with the bis-stannane. This represents a mild alternative to traditional syntheses of these products, with strong nucleophilic reagents. Subsequent lithiation and carboxylation can generate various [alpha]-amino acid derivatives in two steps from imines, acid chlorides and CO2. In chapter 4, we describe the copper-catalyzed aerobic oxidation of alcohols without the use nitroxyl co-catalysts. We demonstrate that a Cu/di-tert-butylethylenediamine (DBED) catalyst can generate active copper-oxygen species capable of mediating alcohol oxidation. This catalyst operates at ambient pressure and temperature and retains activity for challenging substrates such as secondary unactivated alcohols. Notably, this system likely operates via a distinct mechanistic pathway compared to nitroxyl based oxidations, and as a result, shows different alcohol chemoselectivity. In chapter 5, we describe the effects of the counterion (X-) in copper-catalyzed aerobic oxidation, and apply these to the oxidation of primary amines. By manipulating the copper salt employed, we have been able to design active catalysts for the oxidation of amines to nitriles (with CuI/DBED), or to imines (with CuPF6). Both of these reactions occur at unusually mild conditions (ambient temperature and pressure), and provide a practical approach to selective amine oxidation without added nitroxyl co-catalysts. " --

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 Development of Palladium catalyzed Desulfinative Coupling Reactions written by Dirk Ortgies and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A key aspect of organic chemistry is the development of methods to gain an easier and more economical access to a variety of useful molecules. Since the discovery palladium-catalyzed cross-coupling reactions, transformations that employ an organometallic reagent as a nucleophilic coupling partner together with an aryl halide or pseudo-halide as the electrophile have set the standard for carbon-carbon bond formation. More recently, chemists have become increasingly aware of how their science affects the environment and that it has been strongly dependent on a finite amount of resources. Therefore principles of a greener chemistry have been applied to guide researchers in the development of novel reactions towards a more sustainable, less hazardous and less wasteful chemistry.Decarboxylative cross-couplings employ aromatic carboxylic acids as replacement for the organometallic reagent and form only carbon dioxide as by-product, but decarboxylations of benzoic acids require a metal co-catalyst. Therefore, desulfinative cross-couplings, which rely on aryl sulfinate salts as the nucleophilic coupling-partner, have also gained attention. Bench-stable sulfinates can undergo metal-assisted desulfination under extrusion of sulfur dioxide in analogy to the decarboxylation of benzoates. This thesis started with the adaptation of conditions from a heteroaromatic decarboxylative cross-coupling towards a desulfinative reaction of aryl sulfinates with aryl bromides. The method gave good results with electron-poor aryl bromides and further studies of the reaction demonstrated that it is indeed a palladium(0)-catalyzed cross-coupling and neither a nucleophilic aromatic substitution nor a radical transformation.During these studies, a tendency of the aryl sulfinate to undergo C-C homocoupling reactions was noted. We were interested in developing a catalytic reaction to improve access to symmetrical biphenyls. Conditions in aqueous media employing copper(II) dichloride for the reoxidation of the palladium catalyst as well as a reaction catalytic in palladium and TEMPO with molecular oxygen as terminal oxidant were successfully established. Further studies led to the development of a ligand-free desulfinative cross-coupling reaction that demonstrated an excellent reactivity of aryl sulfinates with bromobenzonitriles. Additional work to discover more sustainable reaction conditions resulted in the development of a method in isopropanol for bromobenzonitriles and attempts to adapt the reaction for aryl chlorides yielded a desulfinative cross-coupling with chlorobenzonitrile.In summary, the research presented herein describes novel methods for the preparation of carbon-carbon bonds via palladium-catalyzed coupling reactions of aryl sulfinates. It increases the scope of synthetically applicable reactions of aryl sulfinates and enhances the knowledge on their reactivity.

Download or read book Palladium catalyzed C N and C O Cross coupling Reactions written by Paula Ruiz-Castillo and published by . This book was released on 2016 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1: This chapter describes a general method for the of the Pd-catalyzed N-arylation of hindered [alpha],[alpha],[alpha]-trisubstituted primary amines. The reaction utilized catalysts based on two biaryl phosphine ligands, which were developed via kinetics-based mechanistic analysis and rational design. These studies led to the first example of catalyst based on a hybrid (alkyl)aryl biaryl phosphine ligand that provides better results that its dialkyl- or diarylbiaryl analogues. The C-N coupling was efficient for a wide range of (hetero)aryl chlorides and bromides under mild conditions. Chapter 2: This chapter relates the development of the Pd-catalyzed C-O coupling of primary alkyl alcohols. The reaction of primary aliphatic alcohols bearing [beta]-hydrogen atoms can lead to undesired [beta]-hydride elimination pathways instead of the target reductive elimination from the [LPd(Ar)OAlk] intermediate, especially when using electron-rich aryl halides. Additionally, aryl chlorides have been shown to be more challenging coupling partners than the corresponding aryl bromides. The use of catalysts based on commercially available ligand t-BuBrettPhos and a novel hybrid ligand, AdCyBrettPhos, have allowed the C-O coupling reaction to proceed effectively at room temperature, minimizing the side reaction. A variety of functionalized primary alcohols have been successfully coupled with (hetero)aryl bromides and chlorides giving rise to medicinally interesting products. Chapter 3: This chapter is a compilation of the applications of Pd-catalyzed C-N coupling in various fields of chemical research since 2008. This work includes the reactions of nine classes of nitrogen-based coupling partners in the 1) synthesis of heterocycles, 2) medicinal chemistry, 3) process chemistry, 4) synthesis of natural products, 5) organic materials and chemical biology, and 6) synthesis of ligands. The large number of applications highlights the versatility and utility of this transformation both in academic and industrial settings.

Download or read book Development and Application of Palladium catalyzed Carbon nitrogen Bond Forming Reactions written by Seble-Hiwot Teshome Wagaw and published by . This book was released on 1999 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Harnessing the Reactivity of Palladium carbenes written by Avinash Khanna and published by . This book was released on 2013 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of stereogenic C-C bonds via transition metal catalysis has become an indispensible tool for synthetic chemists. Palladium-carbene complexes offer new disconnections in cross-couplings and C-C bond formations. The doctoral studies detailed herein have focused on the development of catalytic methods for the construction of C-C and C-N bonds via a variety of Pd-carbene intermediates. These efforts and the preliminary studies of asymmetric induction in Pd-carbenylation are discussed in this thesis. Palladium-catalyzed carbenylative cross-coupling reactions are gaining increasing attention as analogs of carbonylative reactions with carbon monoxide. The insertion of carbene ligands creates a new stereogenic center, which warrants their detailed study. Early applications of insertional cross-couplings involved exclusively commercially available diazo compounds such as trimethylsilyl diazomethane (TMSD). Efforts to access phenylcarbenes by analogous diazo compounds have been obviated by the highly reactive nature of unstabilized aryldiazomethanes. Alternatively, metalated N-tosylhydrazones decompose to generate aryldiazo compounds and were found to produce metal-carbene intermediates in situ. In an effort to expand the scope of palladium-carbenylations, vinyl iodide 1a was employed to test the participation of N-tosylhydrazones as phenylcarbene precursors in carbenylative aminations. The optimization and broad substrate scope of the reaction led to the total synthesis of the alkaloid natural caulophyllumine B. The carbenylative amination also led to the discovery of a novel palladium (0) catalyzed dimerization reaction of [omega]-aminovinylhalides. The dimerization was optimized and found to be a selective method for aminocyclizations to form pyrrolidines and piperidines. Results from a crossover experiment were most consistent with the intermediacy of a palladium(0)alkylidene intermediate. Mechanistically, we hypothesized that the bispyrrolidines were arising from Pd-carbene intermediates. Since carbene intermediates are known to be precursors to cyclopropanes, we showed that they could be trapped with norbornadiene. We were able to exploit the transient carbene intermediates to selectively form cyclopropanes or bis-pyrrolidines. Upon optimization of reaction conditions, cyclopropanation was achieved with a variety of vinyl halides. These results provide a rare example of vinyl halides serving as metal-carbene precursors. These results coupled with those from the dimerization of vinyl halides offer a new mechanistic insight into palladium-catalysis.

Download or read book Palladium catalyzed C N Cross coupling Reactions Toward the Synthesis of Drug like Molecules written by Camille Z. McAvoy and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of methodologies for C-N bond formation reactions is an important scientific challenge because of many academic and industrial applications. This work will focus particularly on palladium-catalyzed cross-couplings of amine-containing compounds with aryl halides. The scope of the BrettPhos precatalyst for the cross-coupling of ortho-substituted aryl iodides with amides is studied using substrates with a variety of functional groups. Due to potential metal-chelating issues with some of the substrates used in this study, a proposed ligand synthesis is discussed in which one of the methoxy groups of BrettPhos is replaced with a morpholine capable of occupying palladium's open coordination site during its catalytic cycle. A final C-N bond formation study focuses on the cross-coupling of aryl halides with amidine salts. For this cross-coupling, a methodology has been developed that can be applied to various electron-rich, electron-poor, and electron-neutral substrates. Furthermore, the products of this cross-coupling can be used for a subsequent electrocyclization through a reaction with aldehyde, demonstrating that a relatively simple two-pot methodology can be used to make relatively complex substrates with pharmaceutical applications. Both amides and amidines are common moieties in drug-like molecules because of the various biological activities of these functional groups. Potential medicinal applications of the developed cross-coupling of amidine salts with aryl halides methodology are described. Thus, methodologies for various palladium-catalyzed, C-N cross-couplings as well as a potential ligand synthesis to be used for palladium catalysis are herein discussed.

Download or read book Palladium and Nickel catalyzed C N Cross coupling Reactions Featuring Soluble Organic Bases written by Joseph Michael Dennis (Jr.) and published by . This book was released on 2020 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1: Breaking the Base Barrier: An Electron-Deficient Palladium Catalyst Enables the Use of a Common Soluble Base in C-N Coupling Due to the low intrinsic acidity of amines, palladium-catalyzed C-N cross-coupling plagued continuously by the necessity to employ strong, inorganic, or insoluble bases. To surmount the many Due to the low intrinsic acidity of amines, palladium-catalyzed C-N crosscoupling has been practical obstacles associated with these reagents, we utilized a commercially available dialkyl triarylmonophosphine-supported palladium catalyst that facilitates a broad range of C-N coupling reactions in the presence of weak, soluble bases. The mild and general reaction conditions show extraordinary tolerance for even highly base-sensitive functional groups. Additionally, insightful heteronuclear NMR studies using −15N-labeled amine complexes provide evidence for the key acidifying effect of the cationic palladium center. Chapter 2: Pd-Catalyzed C-N Coupling Reactions Facilitated by Organic Bases: Mechanistic Investigation Leads to Enhanced Reactivity in the Arylation of Weakly Binding Amines The ability to use soluble organic amine bases in Pd-catalyzed C-N cross-coupling reactions has provided a long-awaited solution to the many issues associated with employing traditional, heterogeneous reaction conditions. However, little is known about the precise function of these bases in the catalytic cycle or about the effect of variations in base structure on catalyst reactivity. We used 19F NMR to analyze the kinetic behavior of C-N coupling reactions facilitated by different organic bases. In the case of aniline coupling reactions employing DBU, the resting state was a DBU-bound oxidative addition complex, LPd(DBU)(Ar)X, and the reaction was found to be inhibited by base. Generally, however, depending on the binding properties of the chosen organic base, increasing the concentration of the base can have a positive or negative influence on the reaction rate. Furthermore, the electronic nature of the aryl triflate employed in the reaction directly affects the reaction rate. The fastest reaction rates were observed with electronically neutral aryl triflates, while the slowest were observed with highly electron-rich and electrondeficient substrates. We propose a model in which the turnover-limiting step of the catalytic cycle is dependent on the relative nucleophilicity of the base, compared to that of the amine. This hypothesis guided the discovery of new reaction conditions for the coupling of weakly binding amines, including secondary aryl amines, which were unreactive nucleophiles in our original protocol. Chapter 3: Use of a Droplet Platform to Optimize Pd-Catalyzed C-N Coupling Reactions Promoted by Organic Bases Recent advances in Pd-catalyzed carbon-nitrogen cross-coupling have enabled the use of soluble organic bases instead of insoluble or strong inorganic bases that are traditionally employed. The single-phase nature of these reaction conditions facilitates their implementation in continuous flow systems, high-throughput optimization platforms, and large-scale applications. In this work, we utilized an automated microfluidic optimization platform to determine optimal reaction conditions for the couplings of an aryl triflate with four types of commonly employed amine nucleophiles: anilines, amides, primary aliphatic amines, and secondary aliphatic amines. By analyzing trends in catalyst reactivity across different reaction temperatures, base strengths, and base concentrations, we have developed a set of general recommendations for Pd-catalyzed crosscoupling reactions involving organic bases. The optimization algorithm determined that the catalyst supported by the dialkyltriarylmonophosphine ligand AlPhos was the most active in the coupling of each amine nucleophile. Furthermore, our automated optimization revealed that the phosphazene base BTTP can be used to facilitate the coupling of secondary alkylamines and aryl triflates. Chapter 4: The Quest for the Ideal Base: Rational Design of a Nickel Precatalyst Enables Mild, Homogeneous C-N Cross-Coupling Palladium-catalyzed amination reactions using soluble organic bases have provided a solution to the many issues associated with heterogeneous reaction conditions. Still, homogeneous C-N crosscoupling approaches cannot yet employ bases as weak and economical as trialkylamines. Furthermore, organic base-mediated methods have not been developed for Ni(0/II) catalysis, despite some advantages of such systems over analogous Pd-based catalysts. We designed a new air-stable and easily prepared Ni(II) precatalyst bearing an electron-deficient bidentate phosphine ligand that enables the cross-coupling of aryl triflates with aryl amines using triethylamine (TEA) as base. The method is tolerant of sterically-congested coupling partners, as well as those bearing base- and nucleophile-sensitive functional groups. With the aid of density functional theory (DFT) calculations, we determined that the electron-deficient auxiliary ligands decrease both the pK[subscript a] of the Ni-bound amine and the barrier to reductive elimination from the resultant Ni(II)-amido complex. Moreover, we determined that precluding Lewis acid-base complexation between the Ni catalyst and the base, due to steric factors, is important for avoiding catalyst inhibition.

Download or read book Intramolecular Heck Couplings of Unactivated Alkyl Electrophiles written by Luke Firmansjah and published by . This book was released on 2007 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for the palladium-catalyzed intramolecular Heck coupling of unactivated alkyl bromides and chlorides is described. The optimal catalyst system was composed of Pd2(MeO-dba)3 as the metal source and N-heterocyclic carbene SIMes as the ligand, and the influence of both parameters is discussed. Reaction of a diastereomerically pure, deuterium-labeled substrate gave only one diastereomer of product, suggesting that the reaction does not proceed through radical pathway, in contrast to processes currently described in the literature. Mechanistic studies involved the synthesis of novel complex Pd(SIMes)2 and a number of its oxidative addition adducts, which were thought to resemble intermediates along a postulated catalytic cycle. However, the alkylpalladium species thus obtained, which were characterized by X-ray crystallography and which bear freely accessible 3 hydrogen atoms, are air and moisture-stable compounds that display no tendency for P-hydride elimination, even upon heating. These complexes are therefore not thought to be part of the catalytic cycle. It was further demonstrated that while Pd(SIMes)2 is not itself catalytically competent in the reaction, it may serve as a catalyst precursor. Evidence is provided to suggest that the true active catalyst is composed of a mixed ligand complex involving both SIMes and dba ...

Download or read book New Palladium Catalysed Intramolecular Coupling Reactions written by Francesco Mariani and published by . This book was released on 2016 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although sygma-aryl and sygma-vinylpalladium(II) complexes are commonly used as electrophiles in C--C bond forming reactions, recent research has demonstrated that the same palladium intermediates can also react with carbon-heteroatom multiple bonds in a nucleophilic manner. Continuing with the interest of our group on the palladium-catalysed intramolecular coupling of aryl halides whit carbonyl compounds, we have expanded our previous findings to substrates containing other carbon-heteroatom multiple bonds. In this context, the first objective of the PhD Thesis has been the study of the dual nature of the sygma-arylpalladium(II) species in aldehyde containing compounds. Thus, after some preliminary studies on the ambiphilic character of the sygma-arylpalladium(II) intermediates involved in the palladium-catalysed intramolecular reactions of (2-iodoanilino)-aldehydes, we have described an efficient new methodology for the synthesis of dibenzo[b, e]azepin-11-ones based on the intramolecular acylation of aryl iodides with aldehydes. Continuing whit our interest in these nucleophilic addition processes, we have developed an efficient methodology for the preparation of a small library of tetrahydroisoquinolin-4-ols based on the palladium-catalysed intramolecular nucleophilic addition of a-(2-iodobenzylamino)- aldehydes. Finally, we have expanded the influence of the heteroatom (nitrogen, oxygen, and sulphur) on the course of the palladium-catalysed intramolecular reactions of aryl iodides and aldehydes having heteroatom--containing tethers. Through an extensive experimental-computational (DFT) study we have concluded that the nature of the heteroatom in the tether is not decisive for the outcome of these reactions. Continuing our research for methodologies that help us to increase the synthetic potential of organopalladium chemistry, we decide to investigate the feasibility of the palladium-catalysed intramolecular coupling of aryl halides and diazoderivatives as a methodology for the synthesis of nitrogen heterocycles. So, the second objective was the study of the Pd-catalysed intramolecular coupling of aryl halides with N-tosylhydrazones and sygma-diazoesters in nitrogen containing substrates. We have found that palladium can be used to catalyse the C(sp3)-H insertion of metal carbenoids derived from sygma-diazoesters to form pyrrolidines through intramolecular assembly of C(sp3)-C(sp3) bonds. This reaction is the first example of palladium-catalyzed C(sp3)-C(sp3) bond assembly starting from diazocarbonyl compounds. The coupling reaction can be catalyzed by both Pd(0) and Pd(II), is regioselective, and shows a broad functional group tolerance.

Download or read book Synthesis of Novel N heterocyclic Carbene palladium Complexes and Their Catalytic Activity written by Daniel P. Guest and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Understanding of the Reaction Mechanism as the Basis for the Design of Highly Active Heterogeneous Palladium Catalysts and Optimized Reaction Conditions for Coupling Reactions in Organic Synthesis written by Wolfgang Kleist and published by . This book was released on 2006 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reversible Oxidative Addition in Palladium Catalysis written by Stephen Newman and published by . This book was released on 2012 with total page 986 pages. Available in PDF, EPUB and Kindle. Book excerpt: