6.4. Polyynes 3123 6.5. Using R-Hydroxy Stannanes 3124 6.6. Using the Hurtley Reaction 3124 6.7. Using a Methylenation Reaction 3125 7. Conclusions and Future Prospects 3125 8. Uncommon Abbreviations 3125 9. Acknowledgments 3125 10. Note Added in Proof 3125 11. References 3126 * Authorstowhomcorrespondenceshouldbeaddressed(evano@chimie.uvsq.fr, nicolas.blanchard@uha.fr). † Université de Versailles Saint Quentin en Yvelines. ‡ Université de Haute-Alsace. Chem. Rev. 2008, 108, 3054–3131 3054

Copper-mediated coupling reactions and their applications in natural products and designed biomolecules synthesis.

Selected patented cross-coupling reaction technologies.

Copper-catalyzed Ullmann condensations are key reactions for the formation of carbon-heteroatom and carbon-carbon bonds in organic synthesis. These reactions can lead to structural moieties that are prevalent in building blocks of active molecules in the life sciences and in many material precursors. An increasing number of publications have appeared concerning Ullmann-type intermolecular reactions for the coupling of aryl and vinyl halides with N, O, and C nucleophiles, and this Minireview highlights recent and major developments in this topic since 2004.

Catalytic C-C, C-N, and C-O Ullmann-type coupling reactions.

140 years ago Adolf von Baeyer proposed the structure of a heteroaromatic compound which revolutionized organic and medical chemistry: indole. After more than a century, indole itself and the complexity of naturally occurring indole derivatives continue to inspire and influence developments in synthetic chemistry. In particular, the ubiquitous presence of indole rings in pharmaceuticals, agrochemicals, and functional materials are testament to the ever increasing interest in the design of mild and efficient synthetic routes to functionalized indole derivatives. This Review emphasizes the achievements in the selective catalytic functionalization of indoles (C-C bond-forming processes) over the last four years.

Catalytic Functionalization of Indoles in a New Dimension

Fluorine has received great attention in all fields of science. “Small atom with a big ego” was the title of the Symposium at the ACS meeting in San Francisco in 2000, where a number of the current scientific and industrial aspects of fluorine chemistry made possible by the small size and high electronegativity of the atom were discussed. This small atom has provided mankind with significant benefits in special products such as poly(tetrafluroethylene) (PTFE), freon, fluoro-liquid crystals, optical fiber, pharmaceutical and agrochemical compounds, and so on, all of which have their own unique properties that are otherwise difficult to obtain.1 For instance, at present, up to 30% of agrochemicals and 10% of pharmaceuticals currently used contain fluorine atoms. Therefore, organic fluorine compounds have received a great deal of interest and attention from the scientists involved in diverse fields of science and technology. Now, not only C-F bond formation but also selective C-F bond activation have become current subjects of active investigation from the viewpoint of effective synthesis of fluoroorganic compounds. The former is highlighted by designing a sophisticated fluorinating reagent for regioand stereocontrolled fluorination and developing versatile multifunctional and easily prepared building blocks. C-F bond formation has been treated extensively in several reviews2 and books.3 The latter is a subject that has been less explored but would be promising for selective defluorination of aliphatic fluorides, cross-coupling with aryl fluorides, and * To whom correspondence should be addressed. Phone: 81-78-803-5799. Fax: 81-78-803-5799. E-mail: amii@kobe-u.ac.jp and uneyamak@cc.okayamau.ac.jp. † Kobe University. ‡ Okayama University. Chem. Rev. 2009, 109, 2119–2183 2119

C-F bond activation in organic synthesis.

Mild, efficient, copper-catalyzed N-arylation procedures for nitrogen heterocycles, amides, carbamates, and C-arylation procedures for malonic acid derivatives have been developed that afford high yields of arylated products with excellent selectivity. The N-arylation of imidazole with aryl bromides or iodides was found to be greatly accelerated by inexpensive, air-stable catalyst systems, combining catalytic copper salts or oxides with a set of structurally simple chelating ligands. The reaction was shown to be compatible with a broad range of aryl halides, encompassing sterically hindered, electron-poor, and electron-rich ones, providing the arylated products under particularly mild conditions (50-82 degrees C). The lower limit in ligand and catalyst loading and the scope of Ullmann-type condensations catalyzed by complexes bearing those ligands with respect to the nucleophile class have also been investigated. Chelating Schiff base Chxn-Py-Al (1c) generates a remarkably general copper catalyst for N-arylation of pyrrole, indole, 1,2,4-triazole, amides, and carbamates; and C-arylation of diethyl malonate, ethyl cyanoacetate, and malononitrile with aryl iodides under mild conditions (50-82 degrees C). The new method reported here is the most successful to date with regard to Ullmann-type arylation of some of these nucleophiles.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/chem.200400582

Highly efficient and mild copper-catalyzed N- and C-arylations with aryl bromides and iodides.

A General and Mild Ullmann-Type Synthesis of Diaryl Ethers

Pd/C-catalyzed room-temperature hydrodehalogenation of aryl halides with hydrazine hydrochloride

The present invention concerns a process for arylating or vinylating or alkynating a nucleophilic compound. More particularly, the invention concerns arylating nitrogen-containing organic derivatives. The arylating or vinylating or alkynating process of the invention consists of reacting a nucleophilic compound with a compound carrying a leaving group and is characterized in that the reaction is carried out in the presence of an effective quantity of a catalyst based on a metallic element M selected from groups (VIII), (Ib) and (IIb) of the periodic table and at least one ligand comprising at least one imine function and at least one supplemental nitrogen atom as the chelating atoms.

Process for arylating or vinylating or alkynating a nucleophilic compound

The invention relates to a method for forming a carbon-carbon or carbon-heteroatom bond by reacting an unsaturated compound carrying a leaving group and a nucleophilic compound, in the absence of a ligand. The aim of the invention is especially to form carbon-nitrogen bonds according to a method for the arylation of nitrogenated organic derivatives. According to the inventive method, a carbon-carbon or carbon-heteroatom bond is formed by reacting an unsaturated compound carrying a leaving group with a nucleophilic compound donating a carbon atom or a heteroatom (HE) that can substitute the leaving group, thus forming a C-C or C-HE bond, in the presence of a copper-based catalyst and a base. Said metal is characterised in that the reaction takes place in the absence of a ligand and in a nitrile-type solvent.

Pascal P. Cellier

Papers

Highly efficient and mild copper-catalyzed N- and C-arylations with aryl bromides and iodides.

A General and Mild Ullmann-Type Synthesis of Diaryl Ethers

Pd/C-catalyzed room-temperature hydrodehalogenation of aryl halides with hydrazine hydrochloride

Process for arylating or vinylating or alkynating a nucleophilic compound

Method of forming a carbon-carbon or carbon-heteroatom linkage