s, or keywords if they used Heck-type chemistry in their syntheses, because it became one of basic tools of organic preparations, a natural way to

http://aether.cmi.ua.ac.be/artikels/Artikels%20Gitte/Artikels/Reviews/Heck%20reactie%20Beletskaya%20%20Chem.%20Rev.%20003009.pdf

The heck reaction as a sharpening stone of palladium catalysis.

Catalytic dehydrogenative cross-coupling: forming carbon-carbon bonds by oxidizing two carbon-hydrogen bonds

Interest in catalysis by metal nanoparticles (NPs) is increasing dramatically, as reflected by the large number of publications in the last five years. This field, "semi-heterogeneous catalysis", is at the frontier between homogeneous and heterogeneous catalysis, and progress has been made in the efficiency and selectivity of reactions and recovery and recyclability of the catalytic materials. Usually NP catalysts are prepared from a metal salt, a reducing agent, and a stabilizer and are supported on an oxide, charcoal, or a zeolite. Besides the polymers and oxides that used to be employed as standard, innovative stabilizers, media, and supports have appeared, such as dendrimers, specific ligands, ionic liquids, surfactants, membranes, carbon nanotubes, and a variety of oxides. Ligand-free procedures have provided remarkable results with extremely low metal loading. The Review presents the recent developments and the use of NP catalysis in organic synthesis, for example, in hydrogenation and C--C coupling reactions, and the heterogeneous oxidation of CO on gold NPs.

Nanoparticles as Recyclable Catalysts: The Frontier between Homogeneous and Heterogeneous Catalysis

3.7. Palladium Nanoparticles as Catalysts 888 3.8. Other Transition-Metal Complexes 888 3.9. Transition-Metal-Free Reactions 889 4. Applications 889 4.1. Alkynylation of Arenes 889 4.2. Alkynylation of Heterocycles 891 4.3. Synthesis of Enynes and Enediynes 894 4.4. Synthesis of Ynones 896 4.5. Synthesis of Carbocyclic Systems 897 4.6. Synthesis of Heterocyclic Systems 898 4.7. Synthesis of Natural Products 903 4.8. Synthesis of Electronic and Electrooptical Molecules 906

https://www.chem.ccu.edu.tw/~joyce/referance/ericyang/Chem.%20Rev/Chem.%20Rev.%202007,%20107,%20874-922.pdf

The Sonogashira Reaction: A Booming Methodology in Synthetic Organic Chemistry†

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).

Recent advances in the transition metal-catalyzed twofold oxidative C–H bond activation strategy for C–C and C–N bond formation

The substituted indole nucleus [indole is the acronym from indigo (the natural dye) and oleum (used for the isolation)] is a structural component of a vast number of biologically active natural and unnatural compounds. The synthesis and functionalization of indoles has been the object of research for over 100 years, and a variety of well-established classical methods are now available, to name a few of them, the Fisher indole synthesis, the Gassman synthesis of indoles from N-halo-anilines, the Madelung cyclization of N-acyl-o-toluidines, the Bischler indole synthesis, the Batcho-Leimgruber synthesis of indoles from o-nitrotoluenes and dimethylformamide acetals, and the reductive cyclization of o-nitrobenzyl ketones.1 In the last 40 years or so, however, palladiumcatalyzed reactions, generally tolerant of a wide range of functionalities and therefore applicable to complex molecules, have achieved an important place in the arsenal of the practicing organic chemist. Since the invention of an industrial process for the palladium-catalyzed production of acetaldehyde from ethylene in the presence of PdCl2 and CuCl2, an everincreasing number of organic transformations have been based on palladium catalysis. Almost every area of the organic synthesis has been deeply influenced by the profound potential of this versatile transition metal, modifying the way organic chemists design and realize synthetic processes.2,3 Because of its catalytic nature, palladium-catalyzed synthesis can provide access to fine chemicals, agrochemical and pharmaceutical intermediates, and active ingredients in fewer steps and with less waste than classical † In memory of Prof. Bianca Rosa Pietroni, a colleague and very close friend. * To whom correspondence should be addressed. Phone: + 39 (06) 4991-2785. Fax: + 30 (06) 4991-2780. E-mail: sandro.cacchi@ uniroma1.it. 2873 Chem. Rev. 2005, 105, 2873−2920

Synthesis and functionalization of indoles through palladium-catalyzed reactions

Update 1 of: Synthesis and Functionalization of Indoles Through Palladium-Catalyzed Reactions

Because of the economic attractiveness and good functional tolerance of copper-catalyzed methods and hence their potential in large-scale applications, during the past few years there have been remarkable advances in the use of copper catalysis in organic synthesis. An impressive number of Ullmann coupling reactions have been described starting from aryl halides and suitable reagents. Recent reports have shown that copper catalysis can also be used in the formation of C heteroatom and C C bonds through selective catalytic activation of aryl C H bonds, a topic of intense current interest that, for the most part, has witnessed the use of palladium-, rhodium-, and ruthenium-based catalysts. In particular, intramolecular copper-catalyzed ortho C H functionalizations through C N and C O bond-forming reactions have been shown to form benzimidazoles and benzoxazoles from amidines and anilides, respectively. Herein, we disclose a new synthesis of multisubstituted indoles from N-aryl enaminones that involves an intramolecular coppercatalyzed aryl C H functionalization through C C bond formation. The indole moiety is prevalent in a vast array of biologically active natural and nonnatural compounds. Consequently, despite the existence of numerous methods for the synthesis of indole derivatives, the development of new, more efficient procedures is a subject of great importance. N-Aryl enaminones 1 were readily prepared through Sonogashira cross-coupling of terminal alkynes with aroyl chlorides, followed by the conjugate addition of anilines with the resultant a,b-ynones. We initiated our study by examining whether the enaminone 1a could be converted into the corresponding indole 2a. Reactions were usually carried out under an atmosphere of air. After an initial screen of copper catalysts (CuSO4, CuCl2, CuI), we found that 2 a could be isolated in 63 % yield by using CuI, Li2CO3, and 1,10-phenanthroline (phen) in dimethyl acetamide (DMA) after 48 h (Table 1, entry 1). Optimization studies were then performed that varied the

Copper-catalyzed C-C bond formation through C-H functionalization: synthesis of multisubstituted indoles from N-aryl enaminones.

This perspective reports on some of the main copper-catalyzed routes to the construction of the pyrrole and furan rings incorporated into the indole and benzo[b]furan systems, respectively. The first part illustrates the synthesis of indoles through cyclizations of 2-alkynylanilid(n)es, preformed or generated in situ, and cyclizationsvia intramolecular N-arylation, N-vinylation, and C–C bond forming reactions. The second part illustrates the synthesis of benzo[b]furans through cyclizations of preformed 2-alkynylphenols, domino synthesis of 2-alkynylphenols/cyclization processes, and cyclizationsvia intramolecular O-arylation reactions.

Sandro Cacchi

Papers

Synthesis and functionalization of indoles through palladium-catalyzed reactions

Update 1 of: Synthesis and Functionalization of Indoles Through Palladium-Catalyzed Reactions

Copper-catalyzed C-C bond formation through C-H functionalization: synthesis of multisubstituted indoles from N-aryl enaminones.

Copper catalysis in the construction of indole and benzo[b]furan rings.

The Aminopalladation/Reductive Elimination Domino Reaction in the Construction of Functionalized Indole Rings