3d Transition Metals for C–H Activation

Chemical Reviews, Год журнала: 2018, Номер 119(4), С. 2192 - 2452

Опубликована: Ноя. 27, 2018

C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these functionalizations required precious 4d or 5d transition metal catalysts. Given cost-effective sustainable nature earth-abundant first row metals, development less toxic, inexpensive 3d catalysts gained considerable recent momentum a significantly more environmentally-benign economically-attractive alternative. Herein, we provide comprehensive overview on until summer 2018.

Язык: Английский

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A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

Chemical Society Reviews, Год журнала: 2018, Номер 47(17), С. 6603 - 6743

Опубликована: Янв. 1, 2018

The present review is devoted to summarizing the recent advances (2015-2017) in field of metal-catalysed group-directed C-H functionalisation. In order clearly showcase molecular diversity that can now be accessed by means directed functionalisation, whole organized following directing groups installed on a substrate. Its aim comprehensive reference work, where specific group easily found, together with transformations which have been carried out it. Hence, primary format this schemes accompanied concise explanatory text, are ordered sections according their chemical structure. feature typical substrates used, products obtained as well required reaction conditions. Importantly, each example commented respect most important positive features and drawbacks, aspects such selectivity, substrate scope, conditions, removal, greenness. targeted readership both experts functionalisation chemistry (to provide overview progress made last years) and, even more so, all organic chemists who want introduce way thinking for design straightforward, efficient step-economic synthetic routes towards molecules interest them. Accordingly, should particular also scientists from industrial R&D sector. overall goal promote application reactions outside research dedicated method development establishing it valuable archetype contemporary R&D, comparable role cross-coupling play date.

Язык: Английский

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Rhodium‐Catalyzed C(sp²)‐ or C(sp³)−H Bond Functionalization Assisted by Removable Directing Groups

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(25), С. 8304 - 8329

Опубликована: Окт. 12, 2018

Abstract In recent years, transition‐metal‐catalyzed C−H activation has become a key strategy in the field of organic synthesis. Rhodium complexes are widely used as catalysts variety functionalization reactions because their high reactivity and selectivity. The availability number rhodium various oxidation states enables diverse reaction patterns to be obtained. Regioselectivity, an important issue chemistry, can accomplished by using directing group assist reaction. However, obtain target functionalized compounds, it is also necessary use that easily removed. A wide range directed catalyzed have been reported date. this Review, we discuss Rh‐catalyzed aided removable such phenol, amine, aldehyde, ketones, ester, acid, sulfonic N‐heteroaromatic derivatives.

Язык: Английский

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Cobalt‐Catalyzed Annulation Reactions via C−H Bond Activation

ChemCatChem, Год журнала: 2017, Номер 10(4), С. 683 - 705

Опубликована: Ноя. 1, 2017

Abstract Considerable research attention has been directed towards the use of first‐row transition metals in organic synthesis. The more abundant, and less expensive cobalt is considered to be an effective alternative for second third‐row noble metals, especially C−H bond functionalization reactions. In this Minireview, we will summarize features, recent achievements Co‐catalyzed directing group assisted activation/cyclization reactions their mechanistic insights.

Язык: Английский

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Cobalt-Catalyzed Enantioselective Hydroarylation of 1,6-Enynes

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(20), С. 9510 - 9517

Опубликована: Апрель 25, 2020

An asymmetric hydroarylative cyclization of enynes involving a C–H bond cleavage is reported. The cobalt-catalyzed cascade generates three new bonds in an atom-economical fashion. products were obtained excellent yields and enantioselectivities as single diastereo- regioisomers. Preliminary mechanistic studies indicate that the reaction shows no intermolecular crossover. This work highlights potential cobalt catalysis functionalization enantioselective domino reactivity.

Язык: Английский

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Cobalt-Catalyzed Oxidant-Free Spirocycle Synthesis by Liberation of Hydrogen

Organic Letters, Год журнала: 2017, Номер 19(17), С. 4640 - 4643

Опубликована: Авг. 21, 2017

The first example of oxidant-free cobalt-catalyzed synthesis five-membered spirocycles is reported from benzimidates and maleimides utilizing nitrobenzene as promoter. In contrast to previously known oxidative C–H functionalization reactions, this transformation occurs efficiently in the absence oxidant accompanied by liberation hydrogen. spiro-lactams were readily achieved hydrolysis as-prepared spirocyclic compounds. Cp*Rh(III) catalyst shows poor reactivity.

Язык: Английский

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Cp*Co^III-Catalyzed Branch-Selective Hydroarylation of Alkynes via C–H Activation: Efficient Access to α-gem-Vinylindoles

ACS Catalysis, Год журнала: 2017, Номер 7(10), С. 7296 - 7304

Опубликована: Сен. 12, 2017

An efficient, atom-economical, and regioselective insertion of indoles into terminal alkynes has been realized via cobalt(III)-catalyzed C–H activation under mild conditions, leading to efficient synthesis α-gem-vinylindoles. The the follows a rare 1,2-selectivity, silyl alkynes, alkyl propargyl alcohols, protected amines are all applicable. mechanism this hydroarylation system studied in detail by combination experimental computational approaches. In reaction regioselectivity is dictated steric effects alkyne substituent, especially protonolysis stage. However, for amines, selectivity results from electronic during step, with being insignificant determination selectivity. internal also coupled high efficiency but low regioselectivity. Comparisons cobalt, rhodium, iridium catalysts have made terms reactivity, both cobalt catalysts.

Язык: Английский

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Cobalt-catalyzed C–H activation: recent progress in heterocyclic chemistry

Catalysis Science & Technology, Год журнала: 2018, Номер 8(23), С. 5983 - 6018

Опубликована: Янв. 1, 2018

Cobalt-catalyzed C–H activation has gone through some major advancements in the past couple of decades.

Язык: Английский

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Rh(III)-Catalyzed Mild Coupling of Nitrones and Azomethine Imines with Alkylidenecyclopropanes via C–H Activation: Facile Access to Bridged Cycles

ACS Catalysis, Год журнала: 2018, Номер 8(5), С. 4194 - 4200

Опубликована: Апрель 3, 2018

Bridged cycles are an important class of structural motif in various biologically active molecules. Rh(III)-catalyzed C–H activation nitrones and azomethine imines the context dipolar addition with alkylidenecyclopropanes (ACPs) have been realized. By taking advantage ring strain ACPs, reaction aryl delivered bridged [3.2.1] bicyclic isoxazolidines, afforded tricyclic pyrazolones under same conditions, where both nitrone imine act as a directing group. All reactions occurred mild conditions broad substrates scope, high efficiency, >20:1 diastereoselectivity. The synthetic applications this protocol also demonstrated.

Язык: Английский

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Cp*Co(III)-Catalyzed C–H Acylmethylation of Arenes by Employing Sulfoxonium Ylides as Carbene Precursors

Organic Letters, Год журнала: 2018, Номер 20(18), С. 5981 - 5984

Опубликована: Сен. 12, 2018

A Cp*Co(III)-catalyzed C-H bond functionalization of a range arenes by employing sulfoxonium ylides as carbene precursors instead diazo compounds and other has been established. This reaction is highly efficient without any additive, possesses high step atom economies, tolerates functional groups.

Язык: Английский

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