François-Xavier Felpin

C-H Arylation of Benzoquinone in Water through Aniline Activation: Synergistic Effect of Graphite-Supported Copper Oxide Nanoparticles

A homemade CuONPs/Gr catalyst was found to be efficient for the C-H arylation of benzoquinone. This methodology represents the first example of a Meerwein arylation catalyzed by a heterogeneous catalyst.

Direct C sp2H and C sp3H Arylation Enabled by Heterogeneous Palladium Catalysts

This review gives an overview of direct CH arylation catalyzed by heterogeneous Pd catalysts. The efficiency of the different forms of heterogeneous Pd catalysts is discussed with a critical view of the transformations attainable. If experimental evidence is provided, mechanistic considerations on the true nature of the catalysis, that is, heterogeneous versus homogeneous, are discussed as well.

Sustainable Heck–Matsuda Reaction with Catalytic Amounts of Diazonium Salts: An Experimental and Theoretical Study

The palladium-catalyzed Heck-Matsuda reaction with a catalytic amount of an in-situ-generated diazonium salt proceeded under mild and sustainable conditions. The reaction proceeded at room temperature, under base-free conditions, and only generated tBuOH, H(2)O, and N(2) as by-products. Ortho-substituted diazonium salts were more-efficiently coupled to methyl acrylate than their corresponding para isomers, which required the addition of anisole as an additive. In support of these experimental data, we carried out theoretical studies to gain a deeper understanding of these reaction outcomes.

Continuous-flow Heck-Matsuda reaction: homogeneous versus heterogeneous palladium catalysts.

This study describes extensive investigations of the Heck-Matsuda reaction carried out by continuous-flow chemistry between aryl diazonium salts generated in situ and methyl acrylate. Our optimized procedures enable sequential aniline diazotization/palladium-catalyzed Heck-Matsuda reaction using either Pd(OAc)2 or PdEnCat 30 as respectively a homogeneous or a heterogeneous source of palladium. This safe chemistry that does not require the handling of hazardous aryl diazonium salts involves inexpensive reagents and solvents, under ligand- and base-free conditions.

Stabilisation of Carbon‐Supported Palladium Nanoparticles through the Formation of an Alloy with Gold: Application to the Sonogashira Reaction

Oh my Gold! Gold atoms stabilise catalytically active palladium nanoparticles when engaged in an alloy heterogenised on carbon. The increased durability makes the Pd-Au/C catalyst more recyclable than the gold-free Pd/C catalyst for the Sonogashira reaction.

Handling diazonium salts in flow for organic and material chemistry

This review gives an overview of transformations involving the use of diazonium salts in flow. The efficiency of the strategies is critically discussed with a special emphasis on the design of the flow devices. If comparative studies with batch chemistry is provided, the input of flow chemistry with regard to the reaction yields and safety issues is discussed as well.

Heterogeneous Palladium Catalysts for Suzuki–Miyaura Coupling Reactions Involving Aryl Diazonium Salts

This Minireview gives a complete overview of the Suzuki–Miyaura coupling reaction involving aryl diazonium salts catalyzed by heterogeneous palladium catalysts. For each process, the preparation and the properties of the heterogeneous catalysts as well as the catalytic system are critically discussed, providing their strengths and weaknesses.

Palladium Nanoparticles Supported on Sulfonic Acid Functionalized Silica as Trifunctional Heterogeneous Catalysts for Heck and Suzuki Reactions

The arylation of acrylates and boronic acids with anilines, through in situ generated aryl diazonium salts, was successfully achieved by using trifunctional heterogeneous catalysts bearing Brønsted acid and metal active sites. The trifunctional materials were prepared by adsorption of palladium nanoparticles, generated by reduction of a solution of Pd(OAc)2 onto a commercially available sulfonic acid functionalized silica. These new trifunctional catalysts act as a 1) proton donor for the diazotization step, 2) counterion for the diazonium salt, and 3) Pd source for the coupling step. This unprecedented strategy, features mild and safe conditions as hazardous aryl diazonium salts are generated in situ and only produces environmentally friendly byproducts such as tBuOH, H2O, and N2.

Chelation‐Assisted Cross‐Coupling of Anilines through In Situ Activation as Diazonium Salts with Boronic Acids under Ligand‐, Base‐, and Salt‐Free Conditions

We describe the coupling of anilines with aryl boronic acids, under ligand-, base-, and salt-free conditions at room temperature. This new reaction proceeds through the formation of an aryl palladium alkoxo complex, which allows the transmetalation step with aryl boronic acids without any external base. Importantly, this sustainable procedure generates only environmentally friendly byproducts such as tBuOH, H2O, N2, and B(OH)3. The reaction mechanism has been deeply investigated through experimental and theoretical studies.

Practical synthesis of indoles and benzofurans in water using a heterogeneous bimetallic catalyst

Summary This paper describes the preparation of indoles, azaindoles and benzofurans in pure water by using a new heterogeneous Pd–Cu/C catalyst through a cascade Sonogashira alkynylation–cyclization sequence. Details of the optimization studies and the substrate scope are discussed. This procedure allows the preparation of heterocycles with good yields and is tolerant to a wide variety of functional groups.