Faïma Lazreg

Decarboxylation of aromatic carboxylic acids by gold(I)-N-heterocyclic carbene (NHC) complexes

A recently isolated gold(I) complex, [Au(IPr)(OH)], permits the transformation of carboxylic acids to the corresponding decarboxylated gold(I)-aryl complex without the use of silver co-catalyst under mild reaction conditions.

Versatile Relay and Cooperative Palladium(0) N-Heterocyclic Carbene/Copper(I) N-Heterocyclic Carbene Catalysis for the Synthesis of Tri- and Tetrasubstituted Alkenes

Two new and efficient dual catalytic procedures for the synthesis of tri‐ and tetrasubstituted alkenes using aryl bromides and chlorides are reported. The formation of these vinyl arenes occurs independently in a one‐pot relay and a one‐pot cooperative procedure using well‐defined Pd and Cu N‐heterocyclic carbene (NHC) complexes. Mechanistic studies were performed to elucidate the key role of the solvent in each procedure as well as the formation of the key intermediate, [Cu(alkenylboron)(NHC)], which allows transmetalation with the Pd‐NHC co‐catalyst in the cooperative catalysis.

A cooperative Pd-Cu system for direct C-H bond arylation.

A novel and efficient method for C-H arylation using well-defined Pd- and Cu-NHC systems has been developed. This process promotes the challenging construction of C-C bonds from arenes or heteroarenes using aryl bromides and chlorides. Mechanistic studies show that [Cu(OH)(NHC)] plays a key role in the C-H activation and is involved in the transmetallation with the Pd-NHC co-catalyst.

Copper N-Heterocyclic Carbene Complexes As Active Catalysts for the Synthesis of 2-Substituted Oxazolines from Nitriles and Aminoalcohols

The reaction between nitriles and aminoalcohols to access 2-substituted oxazolines was investigated. Using copper-NHC complexes, various nitriles were successfully converted into the corresponding oxazolines, under milder and less wasteful conditions than those of previously reported methods.

Light‐Stable Silver N‐Heterocyclic Carbene Catalysts for the Alkynylation of Ketones in Air

N‐Heterocyclic carbene (NHC) silver(I) complexes were employed efficiently in the alkynylation of ketones. These cationic complexes were highly active and efficient under mild conditions and in air without the need for an additive. The mechanism of this transformation was investigated. Experiments suggest that the formation of a silver acetylide key intermediate and the release of one ligand from the silver centre enable the transformation.

Transition Metal-Catalyzed Carboxylation of Organic Substrates with Carbon Dioxide

The development of sustainable chemical processes is a long-standing challenge. Carbon dioxide represents a renewable C1 building block for organic synthesis and industrial applications as an alternative to other common feedstocks which are based on natural gas, petroleum oil, or coal. Apart from the advantages associated with the nontoxicity and abundance of CO2, its utilization further enables the reduction in its atmospheric content, which contributes significantly to the greenhouse effect. Although widespread application of CO2 in organic synthesis – even on an industrial scale – will not be able to fully compensate for the steadily increasing atmospheric quantities produced (mainly by the combustion of fuels), ecological and economical factors make its usage highly desirable. Therefore, tremendous efforts toward activation and utilization of CO2 have been made by the scientific community over the last 30 years, and, as a result, the number of highly efficient transition metal-catalyzed CO2-incorporative reactions has increased dramatically, especially within the last decade. The achievements in the development of sustainable and economic chemical processes for the carboxylation of organic molecules with CO2 are presented in detail in this chapter.

A straightforward metal-free synthesis of 2-substituted thiazolines in air

A base-catalysed procedure for the synthesis of 2-substituted thiazolines from nitriles and cysteamine hydrochloride under solvent-free conditions is presented. This straightforward approach allows high conversion for a broad range of nitriles and an easy isolation of the desired products.