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Metal-catalyzed activations of inert sp2C–H and sp3C–H bonds have recently brought about a revolution in the synthesis of useful molecules and molecular materials. Among them, the catalytic silylation of sp3C–H bonds has been developed due to the interest in the formed sp3C–SiR3 silanes, a stable organometallic species, for carrying out further functionalizations that cannot be directly achieved using sp3C–H bonds. Besides many examples of sp2C–H bond catalytic silylations, metal-catalyzed silylations of sp3C–H bonds have been mostly discovered during the last decade in spite of the high reactivity of the sp3C–SiR3 group. This review will present all the methods of metal-catalyzed silylations of sp3C–H bonds into sp3C–SiR3 functions, discuss the catalytic mechanisms according to various metal-catalysts, and illustrate their applications in synthesis. The review describes successively the intermolecular sp3C–H bond silylations directed first by N-containing heterocycles with silanes using various Ru, Rh, and Ir catalysts and then directed by an amide type function using a Pd(II) catalyst and R3Si–SiR3 reagent. The catalytic intramolecular silylations of sp3C–H bonds can be performed after the catalytic formation of CH–OSiR2H or CH–N(R)SiR2H groups from alcohols, ketones, esters, or amine NH bonds by catalytic hydrosilylation with R2SiH2. Both catalytic processes can be performed using Ir(I) and Rh(I) catalysts with an alkene to capture the formed H2. This reaction with Rh(I) and Ir(I) catalysts can be applied to the formation of 5-membered cyclic silanes from aryl silanes and from alkyl silanes arising from hydrosilylated terminal C＝C bonds of alkenes. Oxidation of the cyclic silane derivatives easily leads to 1,3- and 1,4-diols, from alcohol or ketone precursors and to 1,2-amino alcohols from amines. Several methods show how to transform various heteroatom–methyl groups X–CH3: B–CH3, O–CH3, Si–CH3, N–CH3, Ge–CH3 and S–CH3 into their reactive functionalized X–CH2SiR3 group, using various Ru(0), Ir(I), pincer-Ru(II), or Y catalysts. Examples are shown of catalytic transformations of the allylic moiety CH3–C(R)＝CH2 into its silylated CH2＝C(R)–CH2SiR′3 form via (i) Pd(II) allyl activation, (ii) silyl radical generation with photocatalyst and (iii) dual Ir(I) and Fe(II) catalysts for hydrosilylation of alkanes, via alkene formation, isomerization and hydrosilylation. Finally, a Ru(II)-catalyzed sp3C–H silylation of a methyl group of arylphosphine, directed by a P(III) atom, will be presented. [ABSTRACT FROM AUTHOR]

Herein, we disclose an interesting iron-catalyzed approach for the carbonylation of a tertiary carbon radical. The tertiary carbon radical generated from a 1,5-hydrogen atom transfer can be captured by CO gas smoothly. Various six-membered lactams were constructed chemo-selectively in high yields. [ABSTRACT FROM AUTHOR]

Phosphorus containing molecules have seen widespread applications in the development of innovative metal-ligand catalysts and materials. In recent years, the implementation of late-stage modifications of phosphorus derivatives via ortho-regioselective C–H bond functionalisation has led to faster and better ways for the synthesis of complex ligands by creating new reactions with low impact on the environment. This Feature article highlights transition-metal catalysed regioselective C–H bond functionalisation of phosphorus-containing molecules, in which the phosphorus containing unit plays the role of a directing group for C–H bond activation and the synthesis of new functional phosphorus derivatives. [ABSTRACT FROM AUTHOR]

An efficient hydrogen generation from glycerol and selective synthesis of lactic acid (67%) using pincer-type ruthenium complexes is described. Analysis of the products from glycerol dehydrogenation indicates that improving the efficiency of the decarboxylation step is a key point for further reforming processes. [ABSTRACT FROM AUTHOR]

A novel copper-catalyzed carbonylative acetylation of amines has been developed. With peroxide as the oxidant as well as the methyl source with a copper catalyst under CO pressure, good yields of N-acetyl amides could be obtained. Notably, this is the first example of carbonylative acetylation. [ABSTRACT FROM AUTHOR]

The metal-catalysed successive activation and functionalisation of sp2 C–H bonds is the at heart of synthetic innovations for the development of C–C bond cross-coupling processes. Against expectation catalytic C–H bond transformations can be performed in water as an available, renewable, safe solvent but most importantly as a partner improving the catalyst activity. The objective of the review is to present the catalytic successes for C–H bond transformations in water, discovered mainly during the last six years and involving mostly palladium and ruthenium catalysts, often with the help of a carboxylate partner for the initial key C–H bond deprotonation. Water is beneficial for the direct catalytic arylation with (hetero)aryl halides of functional arene ortho C–H bonds with pyridine, pyrazole, oxazoline, imine, urea, amide… directing groups leading to functional biaryl derivatives, polyheterocycles and polydentate ligands. Metal-catalysed activation of the sp2 C–H bond in water also allows the cross-coupling reaction of two different C–H bonds in the presence of an oxidant and regioselective alkenylations of arenes, heterocycles and functional alkenes are now controlled. Annulation reactions via insertion of alkynes into both activated C–H and heteroatom–hydrogen bonds in water constitute new routes to heterocycles. [ABSTRACT FROM AUTHOR]

The ruthenium(ii)-phosphine catalyst RuCl2(PPh3)(p-cymene) operating water selectively leads to ortho monoarylation, with arylchlorides and heteroarylhalides, of functional arenes. Further catalytic heteroarylation with Ru(OAc)2(p-cymene) in water produces mixed bifunctional derivatives. [ABSTRACT FROM AUTHOR]

Monoalkenylation of arene C–H bonds directed by an oxazoline group to afford bifunctional alkenes is described using [RuCl2(p-cymene)]2 as the catalyst in the presence of 1,1′-binaphthyl-2,2′-diyl hydrogenphosphate (BNPAH) and of Cu(OAc)2·H2O under air. This reaction takes place under mild conditions in ethanol at 80 °C and tolerates the oxazoline function. [ABSTRACT FROM AUTHOR]

The use of esters as blocking groups at the C2 position on a range of 3-substituted 5-membered ring heteroaromatics such as thiophenes or furans, allows control of the regioselectivity for the palladium-catalysed direct arylation at C5-H. This arylation can be followed by easy decarboxylation. This method allows sequential catalytic C5 arylation, decarboxylation and catalytic C2 arylation reactions. [ABSTRACT FROM AUTHOR]

Ru(OAc)2(p-cymene) catalyses the directed dehydrogenative alkenylation of N-aryl pyrazoles by styrene and alkyl acrylates in the presence of a catalytic or stoichiometric amount of Cu(OAc)2·H2O in air; the acetic acid solvent plays a key role. With arene electron-donating groups, ruthenium-catalysed ortho-dialkenylation with alkyl acrylates can be obtained. A new method to generate the oxidative homocoupling of N-phenylpyrazole is provided with the Ru(OAc)2(p-cymene) catalyst. [ABSTRACT FROM AUTHOR]

Acrylonitrile has become a renewable material arising from glycerol. It can now be used as an available key product to introduce a nitrogen-containing functionality into a molecule by cross-metathesis. This review successively presents the developments of catalytic cross-metathesis of acrylonitrile with functional alkenes: (i) the first steps of cross-metathesis of acrylonitrile with simple terminal alkenes, of which the successes were linked to the progressive discoveries of efficient alkene metathesis catalysts, (ii) some contributions of this catalytic reaction to synthesis of complex molecules and (iii) the access to renewable α,̉-bifunctional compounds by acrylonitrile cross-metathesis with fatty acid derivatives, arising from plant oils. The combination of the renewable acrylonitrile and fatty acid derivatives, by catalysis under mild conditions with only ethylene as a by-product, constitutes a clear contribution to green chemistry for the production of useful intermediates. [ABSTRACT FROM AUTHOR]

Direct catalytic diarylation with (hetero)arylhalides of arenes containing an heterocycle (pyridine, oxazoline, pyrazole) has been performed with a ruthenium catalyst assisted by a coordinating base. It constitutes a green process for cross-coupled C–C bond formation without any metal salt waste. The new catalytic system is based on [HRu(codyl)2]BF4/2KY (KY: KOAc, KOPiv, KPI (potassium phtalimide)] in which the assisting ligand Y promotes the initial cleavage of C–H bonds. It is shown that the efficiency of the Ru/2KY system strongly depends on the nature of both substrates. [ABSTRACT FROM AUTHOR]

Direct catalytic diarylation with (hetero)arylhalides of arenes containing an heterocycle (pyridine, oxazoline, pyrazole) has been performed with a ruthenium catalyst assisted by a coordinating base. It constitutes a green process for cross-coupled C–C bond formation without any metal salt waste. The new catalytic system is based on [HRu(codyl)2]BF4/2KY (KY: KOAc, KOPiv, KPI (potassium phtalimide)] in which the assisting ligand Y promotes the initial cleavage of C–H bonds. It is shown that the efficiency of the Ru/2KY system strongly depends on the nature of both substrates. [ABSTRACT FROM AUTHOR]

A hexabenzimidazole ligand was synthesised and used to prepare a hexakis{benzimidazole–ruthenium(ii)} complex containing six RuCl2(arene) units of which the X-ray structure analysis shows a helical arrangement with alternating up and down benzymidazole–ruthenium(ii) branches attached to a central benzene ring. The reactivity of the prepared complex with phosphite and carbonate was investigated and revealed the weakness of (benzimidazole)N–Ru bonds and the release of the polydentate ligand. [ABSTRACT FROM AUTHOR]

The sp³C-H bond functionalisation of 2-pyridyl ethanols upon reaction with alkenes, in the presence of a [RuCl2(arene)]2 catalyst and Cu(OAc)2-H2O, is performed under mild conditions without additional base. This reaction proceeds via a tandem alcohol dehydrogenation/alkylation with alkenes of the resulting ketone at its a sp³C-H bond. [ABSTRACT FROM AUTHOR]