Bond Formations between Two Nucleophiles: Transition Metal Catalyzed Oxidative Cross-Coupling Reactions
TL;DR: Oxidative X-X Bond Formations between Two Nucleophiles 1819 5.1.
Abstract: 3.1. C-M and X-H as Nucleophiles 1806 3.2. C-H and X-M as Nucleophiles 1809 3.2.1. C-Halogen Bond Formations 1809 3.2.2. C-O Bond Formations 1812 3.3. C-H and X-H as Nucleophiles 1812 3.3.1. C-O Bond Formations 1812 3.3.2. C-N Bond Formations 1815 4. Oxidative X-X Bond Formations between Two Nucleophiles 1819 5. Conclusions 1819 Author Information 1819 Biographies 1819 Acknowledgment 1820 References 1820
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TL;DR: This Review provides an overview of C-H bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.
Abstract: The direct functionalization of C-H bonds in organic compounds has recently emerged as a powerful and ideal method for the formation of carbon-carbon and carbon-heteroatom bonds. This Review provides an overview of C-H bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.
2,391 citations
TL;DR: This critical review covers the recent progresses on the regioselective dehydrogenative direct coupling reaction of heteroarenes, including arylation, olefination, alkynylation, and amination/amidation mainly utilizing transition metal catalysts.
Abstract: The direct functionalization of heterocyclic compounds has emerged as one of the most important topics in the field of metal-catalyzed C–H bond activation due to the fact that products are an important synthetic motif in organic synthesis, the pharmaceutical industry, and materials science. This critical review covers the recent progresses on the regioselective dehydrogenative direct coupling reaction of heteroarenes, including arylation, olefination, alkynylation, and amination/amidation mainly utilizing transition metal catalysts (113 references).
2,062 citations
TL;DR: The facile construction of C-E (E = C, N, S, or O) bonds makes Rh(III) catalysis an attractive step-economic approach to value-added molecules from readily available starting materials.
Abstract: Rhodium(III)-catalyzed direct functionalization of C-H bonds under oxidative conditions leading to C-C, C-N, and C-O bond formation is reviewed. Various arene substrates bearing nitrogen and oxygen directing groups are covered in their coupling with unsaturated partners such as alkenes and alkynes. The facile construction of C-E (E = C, N, S, or O) bonds makes Rh(III) catalysis an attractive step-economic approach to value-added molecules from readily available starting materials. Comparisons and contrasts between rhodium(III) and palladium(II)-catalyzed oxidative coupling are made. The remarkable diversity of structures accessible is demonstrated with various recent examples, with a proposed mechanism for each transformation being briefly summarized (critical review, 138 references).
1,899 citations
TL;DR: A critical appraisal of different synthetic approaches to Cu and Cu-based nanoparticles and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications in catalysis.
Abstract: The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...
1,823 citations
TL;DR: This Review highlights the recent progress in the field of cross-dehydrogenative C sp 3C formations and provides a comprehensive overview on existing procedures and employed methodologies.
Abstract: Over the last decade, substantial research has led to the introduction of an impressive number of efficient procedures which allow the selective construction of CC bonds by directly connecting two different CH bonds under oxidative conditions. Common to these methodologies is the generation of the reactive intermediates in situ by activation of both CH bonds. This strategy was introduced by the group of Li as cross-dehydrogenative coupling (CDC) and discloses waste-minimized synthetic alternatives to classic coupling procedures which rely on the use of prefunctionalized starting materials. This Review highlights the recent progress in the field of cross-dehydrogenative C sp 3C formations and provides a comprehensive overview on existing procedures and employed methodologies.
1,528 citations
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TL;DR: This is the first comprehensive review encompassing the large body of work in this field over the past 5 years, and will focus specifically on ligand-directed C–H functionalization reactions catalyzed by palladium.
Abstract: 1.1 Introduction to Pd-catalyzed directed C–H functionalization
The development of methods for the direct conversion of carbon–hydrogen bonds into carbon-oxygen, carbon-halogen, carbon-nitrogen, carbon-sulfur, and carbon-carbon bonds remains a critical challenge in organic chemistry. Mild and selective transformations of this type will undoubtedly find widespread application across the chemical field, including in the synthesis of pharmaceuticals, natural products, agrochemicals, polymers, and feedstock commodity chemicals. Traditional approaches for the formation of such functional groups rely on pre-functionalized starting materials for both reactivity and selectivity. However, the requirement for installing a functional group prior to the desired C–O, C–X, C–N, C–S, or C–C bond adds costly chemical steps to the overall construction of a molecule. As such, circumventing this issue will not only improve atom economy but also increase the overall efficiency of multi-step synthetic sequences.
Direct C–H bond functionalization reactions are limited by two fundamental challenges: (i) the inert nature of most carbon-hydrogen bonds and (ii) the requirement to control site selectivity in molecules that contain diverse C–H groups. A multitude of studies have addressed the first challenge by demonstrating that transition metals can react with C–H bonds to produce C–M bonds in a process known as “C–H activation”.1 The resulting C–M bonds are far more reactive than their C–H counterparts, and in many cases they can be converted to new functional groups under mild conditions.
The second major challenge is achieving selective functionalization of a single C–H bond within a complex molecule. While several different strategies have been employed to address this issue, the most common (and the subject of the current review) involves the use of substrates that contain coordinating ligands. These ligands (often termed “directing groups”) bind to the metal center and selectively deliver the catalyst to a proximal C–H bond. Many different transition metals, including Ru, Rh, Pt, and Pd, undergo stoichiometric ligand-directed C–H activation reactions (also known as cyclometalation).2,3 Furthermore, over the past 15 years, a variety of catalytic carbon-carbon bond-forming processes have been developed that involve cyclometalation as a key step.1b–d,4
The current review will focus specifically on ligand-directed C–H functionalization reactions catalyzed by palladium. Palladium complexes are particularly attractive catalysts for such transformations for several reasons. First, ligand-directed C–H functionalization at Pd centers can be used to install many different types of bonds, including carbon-oxygen, carbon-halogen, carbon-nitrogen, carbon-sulfur, and carbon-carbon linkages. Few other catalysts allow such diverse bond constructions,5,6,7 and this versatility is predominantly the result of two key features: (i) the compatibility of many PdII catalysts with oxidants and (ii) the ability to selectively functionalize cyclopalladated intermediates. Second, palladium participates in cyclometalation with a wide variety of directing groups, and, unlike many other transition metals, promotes C–H activation at both sp2 and sp3 C–H sites. Finally, the vast majority of Pd-catalyzed directed C–H functionalization reactions can be performed in the presence of ambient air and moisture, making them exceptionally practical for applications in organic synthesis.
While several accounts have described recent advances, this is the first comprehensive review encompassing the large body of work in this field over the past 5 years (2004–2009). Both synthetic applications and mechanistic aspects of these transformations are discussed where appropriate, and the review is organized on the basis of the type of bond being formed.
5,179 citations
25 Aug 2004
TL;DR: In this paper, the authors present an approach to the formation of C-X (X = N, O, S) bonds in metal-catalyzed cross-coupling reactions.
Abstract: Preface.List of Contributors.1 Mechanistic Aspects of Metal-Catalyzed C,C- and C,X-Bond-Forming Reactions (Antonio M. Echavarren and Diego J. Cardenas).1.1 Mechanisms of Cross-Coupling Reactions.1.2 Formation of C,C-Bonds in the Palladium-Catalyzed alpha-Arylation of Carbonyl Compounds and Nitriles.1.3 Key Intermediates in the Formation of C-X (X = N, O, S) bonds in Metal-Catalyzed Reactions 251.3.1 Reductive Elimination of C-N, C-O, and C-S Bonds From Organopalladium(II) Complexes.1.4 Summary and Outlook.Abbreviations.References.2 Metal-Catalyzed Cross-Coupling Reactions of Organoboron Compounds with Organic Halides (Norio Miyaura).2.1 Introduction.2.2 Advances in the Synthesis of Organoboron Compounds.2.3 Reaction Mechanism.2.4 Reaction Conditions.2.5 Side Reactions.2.6 Reactions of B-Alkyl Compounds.2.7 Reactions of B-Alkenyl Compounds.2.8 Reactions of B-Aryl Compounds.2.9 Reactions of B-Allyl and B-Alkynyl Compounds.2.10 Reactions Giving Ketones.2.11 Dimerization of Arylboronic Acids.2.12 N-, O-, and S-Arylation.Abbreviations.References.3 Organotin Reagents in Cross-Coupling Reactions (Terence N. Mitchell).3.1 Introduction.3.2 Mechanism and Methodology.3.3 Natural Product Synthesis.3.4 Organic Synthesis.3.5 Polymer Chemistry.3.6 Inorganic Synthesis.3.7 Conclusions.3.8 Experimental Procedures.Abbreviations.References.4 Organosilicon Compounds in Cross-Coupling Reactions (Scott E. Denmark and Ramzi F. Sweis).4.1 Introduction.4.2 Modern Organosilicon-Cross-Coupling.4.3 Mechanistic Studies in Silicon-Cross-Coupling.4.4 Applications to Total Synthesis.4.5 Summary and Outlook.4.6 Experimental Procedures.Abbreviations.References.5 Cross-Coupling of Organyl Halides with Alkenes: The Heck Reaction (Stefan Brase and Armin de Meijere).5.1 Introduction.5.2 Principles.5.3 Cascade Reactions and Multiple Couplings.5.4 Related Palladium-Catalyzed Reactions.5.5 Enantioselective Heck-Type Reactions.5.6 Syntheses of Heterocycles, Natural Products and Other Biologically Active Compounds Applying Heck Reactions.5.7 Carbopalladation Reactions in Solid-Phase Syntheses.5.8 The Heck Reaction in Fine Chemicals Syntheses.5.9 Conclusions.5.10 Experimental Procedures.Acknowledgments.Abbreviations and Acronyms.References.6 Cross-Coupling Reactions to sp Carbon Atoms (Jeremiah A. Marsden and Michael M. Haley).6.1 Introduction.6.2 Alkynylcopper Reagents.6.3 Alkynyltin Reagents.6.4 Alkynylzinc Reagents.6.5 Alkynylboron Reagents.6.6 Alkynylsilicon Reagents.6.7 Alkynylmagnesium Reagents.6.8 Other Alkynylmetals.6.9 Concluding Remarks.6.10 Experimental Procedures.Acknowledgments.Abbreviations and Acronyms.References.7 Carbometallation Reactions (Ilan Marek, Nicka Chinkov, and Daniella Banon-Tenne).7.1 Introduction.7.2 Carbometallation Reactions of Alkynes.7.3 Carbometallation Reactions of Alkenes.7.4 Zinc-Enolate Carbometallation Reactions.7.5 Carbometallation Reactions of Dienes and Enynes.7.6 Carbometallation Reactions of Allenes.7.7 Conclusions.7.8 Experimental Procedures.Acknowledgments.References.8 Palladium-Catalyzed 1,4-Additions to Conjugated Dienes (Jan-E. Backvall).8.1 Introduction.8.2 Palladium(0)-Catalyzed Reactions.8.3 Palladium(II)-Catalyzed Reactions.References.9 Cross-Coupling Reactions via PI-Allylmetal Intermediates (Uli Kazmaier and Matthias Pohlman)9.1 Introduction.9.2 Palladium-Catalyzed Allylic Alkylations.9.3 Allylic Alkylations with Other Transition Metals.9.4 Experimental Procedures.Abbreviations.References.10 Palladium-Catalyzed Coupling Reactions of Propargyl Compounds (Jiro Tsuji and Tadakatsu Mandai).10.1 Introduction.10.2 Classification of Pd-Catalyzed Coupling Reactions of Propargyl Compounds.10.3 Reactions with Insertion into the sp2 Carbon Bond of Allenylpalladium Intermediates (Type I).10.4 Transformations via Transmetallation of Allenylpalladium Intermediates and Related Reactions (Type II).10.5 Reactions with Attack of Soft Carbon and Oxo Nucleophiles on the sp-Carbon of Allenylpalladium Intermediates (Type III).10.6 Experimental Procedures.Abbreviations.References.11 Carbon-Carbon Bond-Forming Reactions Mediated by Organozinc Reagents (Paul Knochel, M. Isabel Calaza, and Eike Hupe).11.1 Introduction.11.2 Methods of Preparation of Zinc Organometallics.11.3 Uncatalyzed Cross-Coupling Reactions.11.4 Copper-Catalyzed Cross-Coupling Reactions.11.5 Transition Metal-Catalyzed Cross-Coupling Reactions.11.6 Conclusions.11.7 Experimental Procedures.Abbreviations.References.12 Carbon-Carbon Bond-Forming Reactions Mediated by Organomagnesium Reagents (Paul Knochel, Ioannis Sapountzis, and Nina Gommermann).12.1 Introduction.12.2 Preparation of Polyfunctionalized Organomagnesium Reagents via a Halogen-Magnesium Exchange.12.3 Conclusions.12.4 Experimental Procedures.References.13 Palladium-Catalyzed Aromatic Carbon-Nitrogen Bond Formation (Lei Jiang and Stephen L. Buchwald).13.1 Introduction.13.2 Mechanistic Studies.13.3 General Features.13.4 Palladium-Catalyzed C-N Bond Formation.13.5 Vinylation.13.6 Amination On Solid Support.13.7 Conclusion.13.8 Representative Experimental Procedures.References.14 The Directed ortho-Metallation (DoM) Cross-Coupling Nexus. Synthetic Methodology for the Formation of Aryl-Aryl and Aryl-Heteroatom-Aryl Bonds (Eric J.-G. Anctil and Victor Snieckus).14.1 Introduction.14.2 The Aim of this Chapter.14.3 Synthetic Methodology derived from the DoM-Cross-Coupling Nexus.14.4 Applications of DoM in Synthesis.14.5 Conclusions and Prognosis.14.6 Selected Experimental Procedures.Abbreviations.References and Notes.15 Palladium- or Nickel-Catalyzed Cross-Coupling with Organometals Containing Zinc, Aluminum, and Zirconium: The Negishi Coupling (Ei-ichi Negishi, Xingzhong Zeng, Ze Tan, Mingxing Qian, Qian Hu, and Zhihong Huang).15.1 Introduction and General Discussion of Changeable Parameters.15.2 Recent Developments in the Negishi Coupling and Related Pd- or Ni-Catalyzed Cross-Coupling Reactions.15.3 Summary and Conclusions.15.4 Representative Experimental Procedures.References.Index.
4,387 citations
TL;DR: A review of palladium-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle can be found in this paper.
Abstract: Pick your Pd partners: A number of catalytic systems have been developed for palladium-catalyzed CH activation/CC bond formation. Recent studies concerning the palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle are discussed (see scheme), and the versatility and practicality of this new mode of catalysis are presented. Unaddressed questions and the potential for development in the field are also addressed.
In the past decade, palladium-catalyzed CH activation/CC bond-forming reactions have emerged as promising new catalytic transformations; however, development in this field is still at an early stage compared to the state of the art in cross-coupling reactions using aryl and alkyl halides. This Review begins with a brief introduction of four extensively investigated modes of catalysis for forming CC bonds from CH bonds: PdII/Pd0, PdII/PdIV, Pd0/PdII/PdIV, and Pd0/PdII catalysis. A more detailed discussion is then directed towards the recent development of palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle. Despite the progress made to date, improving the versatility and practicality of this new reaction remains a tremendous challenge.
3,533 citations
3,281 citations
TL;DR: This review focuses on Rh-catalyzed methods for C-H bond functionalization, which have seen widespread success over the course of the last decade and are discussed in detail in the accompanying articles in this special issue of Chemical Reviews.
Abstract: Once considered the 'holy grail' of organometallic chemistry, synthetically useful reactions employing C-H bond activation have increasingly been developed and applied to natural product and drug synthesis over the past decade. The ubiquity and relative low cost of hydrocarbons makes C-H bond functionalization an attractive alternative to classical C-C bond forming reactions such as cross-coupling, which require organohalides and organometallic reagents. In addition to providing an atom economical alternative to standard cross - coupling strategies, C-H bond functionalization also reduces the production of toxic by-products, thereby contributing to the growing field of reactions with decreased environmental impact. In the area of C-C bond forming reactions that proceed via a C-H activation mechanism, rhodium catalysts stand out for their functional group tolerance and wide range of synthetic utility. Over the course of the last decade, many Rh-catalyzed methods for heteroatom-directed C-H bond functionalization have been reported and will be the focus of this review. Material appearing in the literature prior to 2001 has been reviewed previously and will only be introduced as background when necessary. The synthesis of complex molecules from relatively simple precursors has long been a goal for many organic chemists. The ability to selectively functionalize a molecule with minimal pre-activation can streamline syntheses and expand the opportunities to explore the utility of complex molecules in areas ranging from the pharmaceutical industry to materials science. Indeed, the issue of selectivity is paramount in the development of all C-H bond functionalization methods. Several groups have developed elegant approaches towards achieving selectivity in molecules that possess many sterically and electronically similar C-H bonds. Many of these approaches are discussed in detail in the accompanying articles in this special issue of Chemical Reviews. One approach that has seen widespread success involves the use of a proximal heteroatom that serves as a directing group for the selective functionalization of a specific C-H bond. In a survey of examples of heteroatom-directed Rh catalysis, two mechanistically distinct reaction pathways are revealed. In one case, the heteroatom acts as a chelator to bind the Rh catalyst, facilitating reactivity at a proximal site. In this case, the formation of a five-membered metallacycle provides a favorable driving force in inducing reactivity at the desired location. In the other case, the heteroatom initially coordinates the Rh catalyst and then acts to stabilize the formation of a metal-carbon bond at a proximal site. A true test of the utility of a synthetic method is in its application to the synthesis of natural products or complex molecules. Several groups have demonstrated the applicability of C-H bond functionalization reactions towards complex molecule synthesis. Target-oriented synthesis provides a platform to test the effectiveness of a method in unique chemical and steric environments. In this respect, Rh-catalyzed methods for C-H bond functionalization stand out, with several syntheses being described in the literature that utilize C-H bond functionalization in a key step. These syntheses are highlighted following the discussion of the method they employ.
3,210 citations