Palladium-catalyzed Heck Reaction and Tandem Cross Coupling Reactions for Heterocycle Synthesis

Palladium-catalyzed Heck Reaction and Tandem Cross Coupling Reactions for Heterocycle Synthesis PDF Author: Yuanqing Fang
Publisher:
ISBN: 9780494278918
Category :
Languages : en
Pages : 1130

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Book Description
We have obtained a tetracyclic Heck product with a formal anti-beta -hydride elimination during our post-ARO Pd-catalyzed derivatization studies of dihydronaphthalenes. We found that the yield for this Heck reaction was highly base-dependent, with DABCO being optimal. The catalyst combination of Pd2(dba)3/HP(tBu)3·BF 4 and DABCO was highly efficient for this intramolecular Heck reaction under very mild conditions. Additionally, we observed tandem double Heck reactions, which selectively functionalize two C-Br bonds intra- and intermolecularly. We further developed the concept of selective intramolecular and intermolecular cross-couplings using more general gemdihaloolefin systems, which subsequently led to the development of a variety of heterocycle forming reactions. A tandem C-N/Suzuki coupling of a gemdihalovinylaniline and organoboron reagents including aryl, heteroaryl, alkenylboronic acids (or borate esters) and alkyl boranes afforded a variety of 2-substituted indoles in good to excellent yield. This new method of indole synthesis tolerated various functional groups on all positions of the indole moiety. The orthogonal approach of the sequential copper and palladium-mediated synthesis of 1,2-diarylindoles exploited the availability of diverse organoboron reagents. This new method was successfully applied for the synthesis of three Merck KDR kinase inhibitors in very good overall yields. The Pd-catalyzed tandem couplings of gemdihalovinyl systems were further extended for the synthesis of (1) 2-carbonyl indoles via a C-N coupling, carbonylation, and Suzuki sequence, (2) 2-vinyl indoles via a C-N coupling/Heck reaction sequence, and (3) 2 alkynyl indoles via a C-N/Sonogashira coupling sequence. Furthermore, a Cu-catalyzed tandem Goldberg reaction was developed for the synthesis of imidazoindolones from amino acid-tethered gemdibromoolefins. Preliminary studies towards a modular synthesis of azaindoles from N'-Boc- N'-gemdibromovinyl pyridylamine via a sequential Suzuki/direct arylation protocol was also explored. This new tandem coupling reaction was also successfully extended to two other pharmaceutically important families of heterocycles, azaindoles and thienopyrroles. Suitable substituents (such as alkyl, Boc, and Cbz) on the amino group of the substrate were essential to prevent catalyst poisoning during the tandem process.

Palladium-catalyzed Heck Reaction and Tandem Cross Coupling Reactions for Heterocycle Synthesis

Palladium-catalyzed Heck Reaction and Tandem Cross Coupling Reactions for Heterocycle Synthesis PDF Author: Yuanqing Fang
Publisher:
ISBN: 9780494278918
Category :
Languages : en
Pages : 1130

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Book Description
We have obtained a tetracyclic Heck product with a formal anti-beta -hydride elimination during our post-ARO Pd-catalyzed derivatization studies of dihydronaphthalenes. We found that the yield for this Heck reaction was highly base-dependent, with DABCO being optimal. The catalyst combination of Pd2(dba)3/HP(tBu)3·BF 4 and DABCO was highly efficient for this intramolecular Heck reaction under very mild conditions. Additionally, we observed tandem double Heck reactions, which selectively functionalize two C-Br bonds intra- and intermolecularly. We further developed the concept of selective intramolecular and intermolecular cross-couplings using more general gemdihaloolefin systems, which subsequently led to the development of a variety of heterocycle forming reactions. A tandem C-N/Suzuki coupling of a gemdihalovinylaniline and organoboron reagents including aryl, heteroaryl, alkenylboronic acids (or borate esters) and alkyl boranes afforded a variety of 2-substituted indoles in good to excellent yield. This new method of indole synthesis tolerated various functional groups on all positions of the indole moiety. The orthogonal approach of the sequential copper and palladium-mediated synthesis of 1,2-diarylindoles exploited the availability of diverse organoboron reagents. This new method was successfully applied for the synthesis of three Merck KDR kinase inhibitors in very good overall yields. The Pd-catalyzed tandem couplings of gemdihalovinyl systems were further extended for the synthesis of (1) 2-carbonyl indoles via a C-N coupling, carbonylation, and Suzuki sequence, (2) 2-vinyl indoles via a C-N coupling/Heck reaction sequence, and (3) 2 alkynyl indoles via a C-N/Sonogashira coupling sequence. Furthermore, a Cu-catalyzed tandem Goldberg reaction was developed for the synthesis of imidazoindolones from amino acid-tethered gemdibromoolefins. Preliminary studies towards a modular synthesis of azaindoles from N'-Boc- N'-gemdibromovinyl pyridylamine via a sequential Suzuki/direct arylation protocol was also explored. This new tandem coupling reaction was also successfully extended to two other pharmaceutically important families of heterocycles, azaindoles and thienopyrroles. Suitable substituents (such as alkyl, Boc, and Cbz) on the amino group of the substrate were essential to prevent catalyst poisoning during the tandem process.

Palladium in Heterocyclic Chemistry

Palladium in Heterocyclic Chemistry PDF Author: Jie Jack Li
Publisher: Gulf Professional Publishing
ISBN: 0080914411
Category : Science
Languages : en
Pages : 660

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Book Description
Palladium chemistry, despite its immaturity, has rapidly become an indispensable tool for synthetic organic chemists. Heterocycles are of paramount importance in the pharmaceutical industry and palladium chemistry is one of the most novel and efficient ways of making heterocycles. Today, palladium-catalyzed coupling is the method of choice for the synthesis of a wide range of biaryls and heterobiaryls. The number of applications of palladium chemistry to the syntheses of heterocycles has grown exponentially. These developments highlight the need for a monograph dedicated solely to the palladium chemistry in heterocycles and this book provides a comprehensive explanation of the subject. The principal aim of Palladium in Heterocyclic Chemistry is to highlight important palladium-mediated reactions of heterocycles with emphasis on the unique characteristics of individual heterocycles. 1. Palladium chemistry of heterocycles has its "idiosyncrasies" stemming from their different structural properties from the corresponding carbocyclic aryl compounds. Even activated chloroheterocycles are sufficiently reactive to undergo Pd-catalyzed reactions. As a consequence of &agr and &bgr activation of heteroaryl halides, Pd-catalyzed chemistry may take place regioselectively at the activated positions, a phenomenon rarely seen in carbocyclic aryl halides. In addition, another salient peculiarity in palladium chemistry of heterocycles is the so-called "heteroaryl Heck reaction". For instance, while intermolecular palladium-catalyzed arylations of carbocyclic arenes are rare, palladium-catalyzed arylations of azoles and many other heterocycles readily take place. Therefore, the principal aim of this book is to highlight important palladium-mediated reactions of heterocycles with emphasis on the unique characteristics of individual heterocycles. 2. 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. Many heterocycle-containing natural products (highlighted 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 keeps readers abreast of this fast-growing field. It is also hoped that this book will stimulate more interest and inspire new ideas in this exciting field. - Contains the most up-to-date developments in this fast-moving field - Includes 3 new chapters - Contains material from selected well-respected authors on heterocyclic chemistry

Synthesis of Aromatic Heterocycles and Carbocycles Through Tandem Palladium-Catalyzed Cross-Coupling Reactions of Gem-dihaloolefins

Synthesis of Aromatic Heterocycles and Carbocycles Through Tandem Palladium-Catalyzed Cross-Coupling Reactions of Gem-dihaloolefins PDF Author: Christopher Scott Bryan
Publisher:
ISBN:
Category :
Languages : en
Pages : 798

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Book Description
Our group has developed a strategy for the synthesis of benzofused carbocycles and heterocycles through tandem palladium-catalyzed reactions of gem-dibromoolefins. In these syntheses, one bromide undergoes a Pd-catalyzed cyclization reaction, and the other participates in an orthogonal inter- or intramolecular Pd-catalyzed reaction to functionalize or annulate that ring, respectively.Chapter 2 describes the synthesis of benzothiophenes through the combination of a Pd-catalyzed C--S coupling with an orthogonal Suzuki, Heck, or Sonogashira reaction. This represents the first example of the incorporation of Pd-catalyzed C--S coupling into a tandem reaction.Chapter 1 describes the pairing of an intramolecular C--N bond forming reaction (the Buchwald- Hartwig coupling) with an intramolecular direct arylation for the synthesis of fused indole derivatives. A range of previously unknown heterocycles were synthesized through this method.In Chapter 3, a tandem intramolecular Heck / intermolecular Suzuki reaction is described for the synthesis of methyleneindenes. Studies on this reaction have provided advanced understanding of the mechanism, including how variation of the ligand controls the regioselectivity of the reaction.

Palladium in Heterocyclic Chemistry

Palladium in Heterocyclic Chemistry PDF Author: Jie Jack Li
Publisher: Elsevier
ISBN: 9780080437057
Category : Science
Languages : en
Pages : 436

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Book Description
For this text, Jack Li and Gordon Gribble have compiled an array of referenced examples of the use of palladium in heterocyclic chemistry.

Palladium Assisted Synthesis of Heterocycles

Palladium Assisted Synthesis of Heterocycles PDF Author: Navjeet Kaur
Publisher: CRC Press
ISBN: 1351242598
Category : Medical
Languages : en
Pages : 462

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Book Description
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.

Palladium-Catalyzed Coupling Reactions

Palladium-Catalyzed Coupling Reactions PDF Author: Árpád Molnár
Publisher: John Wiley & Sons
ISBN: 3527648305
Category : Science
Languages : en
Pages : 531

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Book Description
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

Heterocycles from Double-Functionalized Arenes

Heterocycles from Double-Functionalized Arenes PDF Author: Xiao-Feng Wu
Publisher: Royal Society of Chemistry
ISBN: 1782621369
Category : Science
Languages : en
Pages : 315

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Book Description
An introduction to transition metal catalyzed coupling reactions of double-functionalized arenes in heterocycle synthesis.

Handbook of Organopalladium Chemistry for Organic Synthesis

Handbook of Organopalladium Chemistry for Organic Synthesis PDF Author: Ei-ichi Negishi
Publisher: John Wiley & Sons
ISBN: 0471461555
Category : Science
Languages : en
Pages : 1697

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Book Description
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.

The Mizoroki-Heck Reaction

The Mizoroki-Heck Reaction PDF Author: Martin Oestreich
Publisher: John Wiley & Sons
ISBN: 9780470716069
Category : Science
Languages : en
Pages : 608

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Book Description
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)

Heterocycles from Transition Metal Catalysis

Heterocycles from Transition Metal Catalysis PDF Author: András Kotschy
Publisher: Springer Science & Business Media
ISBN: 9781402036248
Category : Science
Languages : en
Pages : 224

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Book Description
"Heterocycles from Transition Metal Catalysis: Formation and Functionalization" provides a concise summary of the prominent role of late transition metal (palladium, nickel, copper) catalysed processes in the synthesis and functionalization of heterocyclic systems. It gives an introduction to catalytic transformations, an overview of the most important reaction types, and presents synthetically useful catalytic processes classified by the target system and the type of transformation. The book provides a representative selection of transition metal catalysed reactions transformations that are relevant in heterocyclic chemistry. In this way, the authors present a useful resource for members of the academic community looking for a textbook as well as industrial chemists in search of a reference book. This book will be an invaluable resource for synthetic chemists, medicinal chemists, and those more generally interested in applied catalysis.