Novel Strategy for the Synthesis of Allenes

Novel Strategy for the Synthesis of Allenes PDF Author:
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ISBN:
Category :
Languages : en
Pages :

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Book Description
Allenes are very important chemical reagents in organic synthesis. Due to their high reactivity, they have been extensively used to carry out a variety of unique and effective chemical transformations including but not limited to ionic and free radical additions and transition metal catalyzed cyclizations. As the chemistry of this group of compounds is explored further and their applications expanded there is a need to develop alternative and cost effective methods for their synthesis. Our approach involves the synthesis of allenes from oxa-bicyclo-alkan-2-ones by methyllithium induced Eschenmoser fragmentation of the bicyclotosylhydrazone derivatives.

Novel Strategy for the Synthesis of Allenes

Novel Strategy for the Synthesis of Allenes PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Allenes are very important chemical reagents in organic synthesis. Due to their high reactivity, they have been extensively used to carry out a variety of unique and effective chemical transformations including but not limited to ionic and free radical additions and transition metal catalyzed cyclizations. As the chemistry of this group of compounds is explored further and their applications expanded there is a need to develop alternative and cost effective methods for their synthesis. Our approach involves the synthesis of allenes from oxa-bicyclo-alkan-2-ones by methyllithium induced Eschenmoser fragmentation of the bicyclotosylhydrazone derivatives.

Novel Strategies for the Synthesis and Cycloisomerization Reactions of Functionalized Allenes

Novel Strategies for the Synthesis and Cycloisomerization Reactions of Functionalized Allenes PDF Author: Gürkan Eray Akpınar
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Novel Strategies for the Synthesis of Tungsten(VI) and Molybdenum(VI) Imido/Oxo Alkylidene NHC Complexes and Their Application in Ring-Opening Metathesis Polymerization

Novel Strategies for the Synthesis of Tungsten(VI) and Molybdenum(VI) Imido/Oxo Alkylidene NHC Complexes and Their Application in Ring-Opening Metathesis Polymerization PDF Author: Janis Musso
Publisher: Cuvillier Verlag
ISBN: 3736966113
Category : Science
Languages : en
Pages : 186

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Book Description
Recently, the synthesis of neutral and cationic group(VI) imido/oxo alkylidene N-heterocyclic carbene (NHC) complexes that tolerate protic functional groups and aldehydes was reported. Unprecedented turnover numbers of up to 1.2 million were found for their silica-supported representatives. Some group(VI) alkylidene NHC complexes even display stability towards moisture and air. Coordination of the NHC to tungsten imido bistriflate precursor complexes, however, can lead to undesired side reactions. This work consequently aimed at the development of novel, more efficient routes to neutral and cationic tungsten imido/oxo alkylidene NHC complexes. In addition, some molybdenum imido alkylidene NHC complexes were targeted. Thereby, the scope of synthetically accessible complexes was broadened and, subsequently, their reactivity in ring-opening metathesis polymerization (ROMP) was probed. Those complexes were used as thermally latent initiators for the ROMP of dicyclopentadiene. Precise determination of the onset temperature of polymerization was achieved via monitoring with differential scanning calorimetry. Furthermore, the selectivity of novel complexes was tested for the formation of stereoregular polymers through ROMP of enantiomerically pure norbornene derivatives, which allowed for the synthesis of up to 98% trans-isotactic or cis-syndiotactic polymers depending on the steric demand of the imido and the alkoxide ligand.

Best Synthetic Methods: Acetylenes, Allenes and Cumulenes

Best Synthetic Methods: Acetylenes, Allenes and Cumulenes PDF Author: Lambert Brandsma
Publisher: Elsevier
ISBN: 0080542204
Category : Science
Languages : en
Pages : 503

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Book Description
There is a vast and often bewildering array of synthetic methods and reagents available to organic chemists today. The Best Synthetic Methods series allows any scientist who is interested in the chemical transformations of molecules to choose between all the alternatives and assess their real advantages and limitations. With the emphasis on laboratory use, these volumes represent a comprehensive and practical guide to modern synthetic organic chemistry. Best Synthetic Methods: Acetylenes, Allenes and Cumulenes is the product of the author's many years practical experience and reading of the original literature. It contains a valuable distillation and critical evaluation of the Best Synthetic Methods for the formation and reaction of molecules containing carbon-carbon triple bonds or cumulative carbon-carbon double bonds. A brief review of each area is provided, but the emphasis in all cases is on describing efficient practical methods to effect the transformations described. The reader can therefore use this book to rapidly review and select the best methods of performing a synthetic conversion to create or modify a molecule containing an acetylene, allene or cumulene functionality. In addition, the documentation of a large number of experimental recipes enables the user to synthesise an unsaturated molecule without the need to access to the original literature. - Reviews and evaluates the various methods for the formation and reaction of acetylenes, cumulenes and allenes - Provides detailed practical experimental for many important reactions - General tips and analytical data are provided from the author's own extensive research in this area

Strategies and Tactics in Organic Synthesis

Strategies and Tactics in Organic Synthesis PDF Author: Michael Harmata
Publisher: Academic Press
ISBN: 0128148063
Category : Science
Languages : en
Pages : 352

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Book Description
Strategies and Tactics in Organic Synthesis, Volume 14, provides a forum for investigators to discuss their approach to the science and art of organic synthesis. Rather than a simple presentation of data or a secondhand analysis, this classic provides stories that vividly demonstrate the power of the human endeavor known as organic synthesis and the creativity and tenacity of its practitioners. Firsthand accounts of each project present the excitement of conception, the frustration of failure, and the joy experienced when either rational thought or good fortune gives rise to the successful completion of a project. This innovative approach also helps illustrate how challenges to further advance the science and art of organic synthesis can be overcome, driving the field forward to meet the demands of society by discovering new reactions, creating new designs, and building molecules with atom and step economies that provide functional solutions to create a better world. - Presents state-of-the-art developments in organic synthesis - Provides insights and offers new perspectives on problem-solving - Written by leading experts in the field - Uses firsthand narrative accounts to vividly illustrate the challenges and joys involved in advancing the science of organic synthesis

Ti (III) catalyzed synthesis of exocyclic allenes and development of new titanocene complexes

Ti (III) catalyzed synthesis of exocyclic allenes and development of new titanocene complexes PDF Author: Carmen Hernández Cervantes
Publisher: Universidad Almería
ISBN: 8416642109
Category : Science
Languages : en
Pages : 329

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Book Description
This thesis deals with the Ti(III) catalyzed synthesis of exocyclic allenes and the development of new titanocene complexes. It is structured in six chapters: Chapter 1 is a general introduction about the generation and reactivity of [TiCp2Cl]. A review about the different [TiCp2Cl] catalyzed or promoted reactions reported to date, is included. Chapter 2 is divided in introduction and results and discussion. In the introduction, an overview about the promoted or catalyzed methodologies, already available for the synthesis of α-allenols, is included. Results and discussion section is sub-divided in other two parts. The first one describes the synthesis of carbocyclic or nitrogen heterocyclic precursors bearing a propargyl halide and a carbonyl group. Next, the [TiCp2Cl] catalyzed synthesis of exocyclic allenols is studied. Additionally, a mechanistic study through deuterium incorporation and reaction of secondary propargyl halide precursors is performed. In the second part, the preparation of oxygen precursors and its cyclization are studied. In chapter 3, there is an introduction about enantioselective syntheses using chiral titanocene catalysts. The results and discussion section deals with the enantioselective cyclization of some of the precursors previously prepared using precatalyst (R,R)-ethylenebis(4,5,6,7-tetrahydro-1-indenyl) titanium(IV), also known as Brintzinger complex. A formal synthesis of the alkaloid (})-stemoamide is carried out in chapter 4, being the key step for this synthesis the generation of an α-allenol derivative through a [TiCp2Cl] catalyzedcyclization. This chapter is also divided in an introduction, in which a review about the different methods of synthesis of stemoamide are included, and results and discussion. Chapter 5 compiles the project that I have developed during my research stay at University of Bonn, under the supervision of Prof. Gansauer. The target of this project was to develop an azide functionalized short linker titanocene derivative with the aim of linking it to a surface by click chemistry. The chapter is divided in introduction and results and discussion. In the introduction the different methodologies for the synthesis of titanocene derivatives are reviewed. This section also includes the background in which this project is based. Chapter 6 includes the experimental part. In this chapter all reactions performed during the development of this thesis, as well as the spectroscopic characterization of compounds, are compiled.

Nitrogenation Strategy for the Synthesis of N-containing Compounds

Nitrogenation Strategy for the Synthesis of N-containing Compounds PDF Author: Ning Jiao
Publisher: Springer
ISBN: 9811028133
Category : Science
Languages : en
Pages : 221

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Book Description
This book focuses on direct nitrogenation strategies to incorporate one or more N-atoms into simple substrates especially hydrocarbons via C–H and/or C–C bond cleavage, which is a green and sustainable way to synthesize nitrogen-containing compounds. The book consists of seven chapters demonstrating interesting advances in the preparation of amines, amides, nitriles, carbamides, azides, and N-heterocyclic compounds and illustrating the mechanisms of these novel transformations. It offers an accessible introduction to nitrogenation reactions for chemists involved in N-compound synthesis and those interested in discovering new reagents and reactions. Ning Jiao is a Professor of Chemistry at Peking University, China.

Synthesis of Acetylenes, Allenes and Cumulenes

Synthesis of Acetylenes, Allenes and Cumulenes PDF Author: H. D. Verkruijsse
Publisher: Academic Press
ISBN: 9780121257514
Category : Science
Languages : en
Pages : 469

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Book Description
There is a vast and often bewildering array of synthetic methods and reagents available to organic chemists today. The Best Synthetic Methods series allows any scientist who is interested in the chemical transformations of molecules to choose between all the alternatives and assess their real advantages and limitations. With the emphasis on laboratory use, these volumes represent a comprehensive and practical guide to modern synthetic organic chemistry. This book is the product of the author's many years practical experience and reading of the original literature. It contains a valuable distillation and critical evaluation of the Best Synthetic Methods for the formation and reaction of molecules containing carbon-carbon triple bonds or cumulative carbon-carbon double bonds. A brief review of each area is provided, but the emphasis in all cases is on describing efficient practical methods to effect the transformations described. The reader can therefore use this book to rapidly review and select the best methods of performing a synthetic conversion to create or modify a molecule containing an acetylene, allene or cumulene functionality. In addition, the documentation of a large number of experimental recipes enables the user to synthesise an unsaturated molecule without the need to access to the original literature. - Reviews and evaluates the various methods for the formation and reaction of acetylenes, cumulenes and allenes. - Provides detailed practical experimental for many important reactions. - General tips and analytical data are provided from the author's own extensive research in this area.

Advances in Transition-Metal Mediated Heterocyclic Synthesis

Advances in Transition-Metal Mediated Heterocyclic Synthesis PDF Author: Daniel Sole
Publisher: Academic Press
ISBN: 0128116528
Category : Science
Languages : en
Pages : 368

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Book Description
Advances in Transition-Metal Mediated Heterocyclic Synthesis provides an overview of recent catalytic reactions involving transition metals to produce heterocyclic compounds. The book is organized according to the type of transformation used to achieve the synthesis of the heterocyclic systems (mainly aza- and oxa-heterocycles). As such, it covers recent applications on the synthesis of heterocycles, also describing the details of the novel transformations in a didactic manner to motivate readers in search of new catalytic processes. The editors have included state-of-the-art strategies, including transition-metal reactions involving unsaturated systems (reactions of allenes, new gold(I)-catalyzed reactions, and Prins reaction). Chapters highlight the versatility of organopalladium chemistry dealing with carbonylative transformations, C-H activation reactions, coupling processes, and the control of the ambiphilic character of organopalladium species. Finally, the book discusses new reactions leading to heterocycles based on C-H activation processes catalyzed by other metals (Rh, Ru, Co). Written by an outstanding team of authors who are leading experts in organometallic chemistry and organic synthesis, this book is a valuable resource not only for chemists mainly focused on synthesis, but also for those interested in reaction mechanisms involving transition metals. - Helpfully organized by transformation type to stimulate the search for new synthetic processes - Completely illustrated and written by global experts - Includes thoughtfully selected strategies chosen by the editors to exemplify the state-of-the-art of the subject, including transition-metal reactions involving unsaturated systems, organopalladium chemistry, and metal-catalyzed C-H activation

Organic Syntheses, Volume 100

Organic Syntheses, Volume 100 PDF Author: Neil K. Garg
Publisher: John Wiley & Sons
ISBN: 1394278128
Category : Science
Languages : en
Pages : 533

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Book Description
The current volume continues the tradition of the Organic Syntheses series, providing carefully checked and edited experimental procedures that describe important synthetic methods, transformations, reagents, and synthetic building blocks or intermediates with demonstrated utility in organic synthesis. These significant and interesting procedures should prove worthwhile to many synthetic chemists working in increasingly diverse areas. A trusted guide for professionals in organic and medicinal chemistry in academia, government, and industries, including pharmaceuticals, fine chemicals, agrochemicals, and biotechnological products.