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International audience; Ruthenium complexes are well known as remarkable pre-catalysts for challenging C-H bond functionalizations. Combining them with other types of chemical reactions in a tandem or one-pot fashion is appealing from a sustainable point of view because it gives access to new strategies to diminish steps devoted to purification and isolation of (sometimes unstable) intermediates. This non-exhaustive review highlights the different approaches enabling these technologies with a particular focus on the understanding for the compatibility of the different reaction sequences. More precisely, ruthenium-catalyzed C-H bond functionalization turned out to be compatible with several organic transformations, metal-mediated reactions and transition metal catalysis. Graphical abstract Highlights-Ruthenium complexes are compatible with one-pot and tandem transformations involving C-H bond functionalization.-Ruthenium-catalyzed C-H bond functionalization has been successfully coupled with other C-H bond functionalization reactions.-Different organic and metal-mediated transformations operate in a concerted manner with ruthenium-catalyzed C-H bond functionalization.-The merger of ruthenium-catalyzed C-H bond functionalization strategies with several transition metal catalysis is attractive for green chemistry and sustainable approaches. Ru catalysis C-H bond functionalization metal catalysis organic reactions cascade and one-pot substrates products metal meditated

International audience; Herein, we disclose a ruthenium-catalyzed regioselective beta-C(sp(3))-H bond functionalization on the piperazine core using aldehydes as alkylating agents. The present transformation appears to go through the dehydrogenation of the piperazine to propagate to enamine in situ, followed by nucleophilic addition to the aldehyde and hydrogenation to result in the regioselective beta-C(sp(3))-H alkylation. A variety of aromatic, heteroaromatic, aliphatic aldehydes were employed for the C-3 alkylation of N-alkyl-N '-p-nitrophenyl substituted piperazines.

International audience; To date, numerous methods have been successfully developed to functionalize N-heteroaryl C-H bonds. In contrast, dearomative tandem functionalization of N-heteroarenes is still a subject to be explored. Reported herein is an example on reductive dearomatization-induced tandem functionalization of N-heteroarenes by ruthenium catalysis, which offers a general method for diastereoselective construction of fused heterocycles featuring a cyclic syn-N, O-acetal motif from N-heteroarenes, phenols, and paraformaldehyde. Mechanistic study reveals that the products are formed via a tandem sequence of pyridyl C-3-benzylation and hydroxymethylation followed by C-2-aryloxylation of N-heteroarenium salts, proceeding with broad substrate scope, good functional group tolerance, high atom efficiency, and applicability for postfunctionalization of some biomedical molecules.

Cyclic monoterpenes are important bio-sourced components present in the resin of pine and citrus trees and some of them are currently produced on an industrial scale especially by the fruit juice industry in Brazil. Therefore, any environmentally benign transformation of these terpenes into new useful products should have a strong impact in terms of sustainable economy. Initially, we were especially interested in the functionalization by olefin metathesis of (-)-β-pinene and (-)-limonene, which are bulky unsaturated monoterpenes featuring a terminal disubstituted carbon‑carbon double bond. The reaction is catalyzed by Hoveyda-Grubbs type ruthenium catalysts in dimethyl carbonate as green solvent and makes possible the clean introduction of ester and nitrile groups in one step without formation of byproducts. We have shown that the utilization of the internal double bond of a symmetrical cross metathesis partner such as dimethyl fumarate, dimethyl maleate, fumaronitrile, 1,4-diacetoxybut-2-ene, 1,4-dichlorobut-2-ene and 2-methylbut-2-ene was very efficient and selective for the functionalization of β-pinene and limonene in the presence of ruthenium catalysts. The influence of oxygenated functional groups in the terpene partner has also been evaluated with terpenoids derived from limonene bearing a ketone and an epoxide group. In this case, these substrates did not inhibit the cross metathesis with any of the cross metathesis partners and the reactivities followed the general rule found for terpenes. The utilization of internal olefins instead of terminal olefins as cross metathesis partners with bulky cyclic terpenes and terpenoids constitutes an elegant route for the straightforward functionalization of their α,α-disubstituted terminal double bond. All cross metathesis products are new compounds and should be evaluated for valuable properties., Les monoterpènes cycliques sont d'importants composants bio-sourcés présents dans la résine des pins et des agrumes et certains d'entre eux sont actuellement produits à l'échelle industrielle, notamment par l'industrie des jus de fruits au Brésil. Par conséquent, toute transformation écologique de ces terpènes en nouveaux produits utiles devrait avoir un fort impact en termes d'économie durable. Initialement, nous nous sommes particulièrement intéressés à la fonctionnalisation par métathèse oléfinique du (-)-β-pinène et du (-)-limonène, qui sont des monoterpènes insaturés volumineux présentant une double liaison carbone-carbone disubstituée terminale. La réaction est catalysée par des catalyseurs au ruthénium de type Hoveyda-Grubbs dans le carbonate de diméthyle comme solvant vert et permet l'introduction propre de groupes ester et nitrile en une seule étape sans formation de sous-produits. Nous avons montré que l'utilisation de la double liaison interne d'un partenaire de métathèse croisée symétrique tel que le fumarate de diméthyle, le maléate de diméthyle, le fumaronitrile, le 1,4-diacétoxybut-2-ène, le 1,4-dichlorobut-2-ène et le 2-méthylbut-2-ène était très efficace et sélective pour la fonctionnalisation du β-pinène et du limonène en présence de catalyseurs au ruthénium. L'influence des groupes fonctionnels oxygénés dans le partenaire terpénique a également été évaluée avec des terpénoïdes dérivés du limonène portant un groupe cétone et un groupe époxyde. Dans ce cas, ces substrats n'ont pas inhibé la métathèse croisée avec aucun des partenaires de métathèse croisée et les réactivités ont suivi la règle générale trouvée pour les terpènes. L'utilisation d'oléfines internes au lieu d'oléfines terminales comme partenaires de métathèse croisée avec des terpènes et des terpénoïdes cycliques volumineux constitue une voie élégante pour la fonctionnalisation directe de leur double liaison terminale α,α-disubstituée. Tous les produits de la métathèse croisée sont de nouveaux composés et doivent être évalués pour leurs propriétés intéressantes., Monoterpenos cíclicos são importantes componentes de origem biológica presentes na resina de pinus e elementos cítricos, sendo alguns deles atualmente produzidos em escala industrial, especialmente pela indústria de sucos de frutas no Brasil. Portanto, qualquer transformação ambientalmente benéfica desses terpenos em novos produtos pode ter um forte impacto em termos de economia sustentável. Inicialmente, estivemos especialmente interessados na funcionalização por metátese de olefinas como o (-)-β-pineno e (-)-limoneno, que são monoterpenos insaturados volumosos com uma dupla ligação carbono-carbono disubstituída terminal. A reação é catalisada por catalisadores de rutênio do tipo Hoveyda-Grubbs em carbonato de dimetila como solvente verde e possibilita a introdução direta de grupos éster e nitrila em uma única etapa, sem formação de subprodutos. Mostramos que a utilização da dupla ligação interna de um reagente de metátese cruzada simétrico, como fumarato de dimetila, maleato de dimetila, fumaronitrila, 1,4-diacetoxibut-2-eno, 1,4-diclorobut-2-eno e 2-metilbut-2-eno foi muito eficiente e seletiva para a funcionalização do β-pineno e limoneno na presença de catalisadores de rutênio. A influência dos grupos funcionais oxigenados no substrato terpênico também foi avaliada com substratos derivados do limoneno contendo um grupo cetona e um grupo epóxido. Neste caso, estes substratos não inibiram a metátese cruzada com nenhum dos reagentes de metátese cruzada e as reatividades seguiram a regra geral encontrada para os terpenos. A utilização de olefinas internas em vez de olefinas terminais como reagentes de metátese cruzada com terpenos cíclicos volumosos e terpenoides constitui uma rota elegante para a simples funcionalização da dupla ligação terminal α,α-disubstituída. Todos os produtos de metátese cruzada são compostos inéditos e devem ser avaliados quanto às suas propriedades.

International audience; The straightforward functionalization of sterically demanding α,α-disubstituted double bonds of the natural products β-pinene and limonene via cross metathesis with symmetrical internal olefins is described. The reaction is catalyzed by Hoveyda-Grubbs type ruthenium catalysts in dimethyl carbonate as green solvent and makes possible the clean introduction of ester and nitrile groups in one step without formation of byproducts.

International audience; Ruthenium-catalyzed C–O bond activation/arylation of methoxy and O-carbamoyl-substituted fluorenones is reported. Established are new reactions of compound 1 (X = H) to aryl (2) and 1,8-diaryl (3) fluorenones. Orthogonal ruthenium-, palladium- and nickel-catalyzed reactions with Suzuki–Miyaura reactions to afford 1,4-diaryl (4) and 1,4,8-triaryl fluorenones (5) are also described. The ready availability of starting methoxy fluorenones by directed ortho and remote metalation tactics confers facility to the presented reactions which may find application in material science areas. DFT calculations have been performed to rationalize the lack of C–H bond reactivity in the ruthenium-catalyzed reaction.

New benzimidazolium sulfonate salts have been prepared and fully characterized. They have been associated in situ with [RuCl2(p-cymene)](2) to generate efficient catalytic systems operating at 120 degrees C under neat conditions in the presence of potassium tert-butylate for selective N-alkylation of primary aromatic amines into secondary amines. (C) 2015 Elsevier B.V. All rights reserved.

International audience; The selective formation of carbon–carbon bond by functionalization of an sp3C–H bond is still a challenge in organic synthesis. There are already examples involving transition metal catalysis. In this chapter we review the use of ruthenium(0) and ruthenium(II) catalysts for the formation of carbon–carbon bonds based on creation of reactive sites by sp3C–H bond activation. We show that in most cases, regioselective sp3C–H bond activation is induced either from functional substrates bearing a directing group, which strongly coordinates the metal centre, or by selective C–H bond activation at the α-carbon of a heteroatom accompanied by hydrogen transfer processes and transient creation of reactive functional groups

International audience; An efficient access to novel trifluoromethyl-substituted phosphonate analogues of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (TIC) derivatives based on regioselective ruthenium-­catalyzed co-cyclotrimerization of functionalized 1,7-diynes with various alkynes has been developed using RuClCp*cod and pre­ferably Grubbs second-generation catalysts.