Pentamethylcyclopentadienyl rhodium(III)–chiral disulfonate hybrid catalysis for enantioselective C–H bond functionalization

Nature Catalysis, Год журнала: 2018, Номер 1(8), С. 585 - 591

Опубликована: Июль 20, 2018

Язык: Английский

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Chiral Carboxylic Acid Enabled Achiral Rhodium(III)‐Catalyzed Enantioselective C−H Functionalization

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(37), С. 12048 - 12052

Опубликована: Июль 24, 2018

Reported is an achiral Cpx RhIII /chiral carboxylic acid catalyzed asymmetric C-H alkylation of diarylmethanamines with a diazomalonate, followed by cyclization and decarboxylation to afford 1,4-dihydroisoquinolin-3(2H)-one. Secondary alkylamines as well nonprotected primary underwent the transformation high enantioselectivities (up 98.5:1.5 e.r.) using newly developed chiral sole source chirality achieve enantioselective cleavage concerted metalation-deprotonation mechanism.

Язык: Английский

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Recent advances using [Cp*Co(CO)I₂] catalysts as a powerful tool for C–H functionalisation

Dalton Transactions, Год журнала: 2017, Номер 46(30), С. 9721 - 9739

Опубликована: Янв. 1, 2017

This perspective highlights recent applications of Cp*Co^III catalysts in C–H functionalisation protocols, exemplifying both terminal couplings and heterocycle formation.

Язык: Английский

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Recent advances in cobalt-catalysed C–H functionalizations

Organic & Biomolecular Chemistry, Год журнала: 2019, Номер 17(48), С. 10119 - 10141

Опубликована: Янв. 1, 2019

Ready availability, low cost and toxicity of cobalt salts have redirected the attention researchers away from noble metals, such as Pd, Rh, Ir, towards Co in field C-H functionalization. In this context, examples Co-catalysed functionalization exponentially grown over last few decades. This present review focuses on most recent developments C(sp2)-H C(sp3)-H functionalizations. Included is also a comprehensive overview enantioselective transformations.

Язык: Английский

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Cp*Co(III)-Catalyzed Annulation of Carboxylic Acids with Alkynes

Organic Letters, Год журнала: 2017, Номер 19(10), С. 2544 - 2547

Опубликована: Апрель 27, 2017

A new procedure for oxidative coupling of aromatic and acrylic acids with alkynes has been developed using abundant, nontoxic, air stable Cp*Co(III) catalyst. The involves initial cyclometalation via weak chelation-assisted C-H bond activation followed by alkyne coordination, insertion, reductive elimination leading to diverse isocoumarins (α-pyranones) in good yields under mild conditions.

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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Cobalt(III)‐Catalyzed Enantioselective Intermolecular Carboamination by C−H Functionalization

Angewandte Chemie International Edition, Год журнала: 2020, Номер 60(2), С. 655 - 659

Опубликована: Сен. 28, 2020

Abstract High‐valent cyclopentadienyl cobalt catalysis is a versatile tool for sustainable C−H bond functionalizations. To harness the full potential of this strategy, control stereoselectivity these processes necessary. Herein, we report highly enantioselective intermolecular carboaminations alkenes through activation N ‐phenoxyamides catalyzed by Co III ‐complexes equipped with chiral (Cp x ) ligands. The method converts widely available acrylates as well bicyclic olefins into attractive enantioenriched isotyrosine derivatives elaborated amino‐substituted scaffolds under very mild conditions. outlined reactivity unique to Cp complexes and complementary 4d‐ 5d‐ precious‐metal catalysts.

Язык: Английский

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Chiral 2-Aryl Ferrocene Carboxylic Acids for the Catalytic Asymmetric C(sp³)–H Activation of Thioamides

Organometallics, Год журнала: 2019, Номер 38(20), С. 3921 - 3926

Опубликована: Июль 29, 2019

Enantioselective C–H functionalization reactions using trivalent group 9 metals (Co, Rh, Ir) have been investigated mainly on the basis of development well-designed chiral cyclopentadienyl (Cp) ligands. Although it has recently demonstrated that carboxylic acids combined with achiral Cp-type ligands can enable highly enantioselective reactions, structural diversity applied remains limited. Here, we report 2-aryl ferrocene acids, which are easily obtained from diastereoselective ortho lithiation and Suzuki–Miyaura coupling, serve as external sources for Cp*CoIII-catalyzed C(sp3)–H amidation α-aryl thioamides dioxazolones.

Язык: Английский

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Regioselective Direct C‐Alkenylation of Indoles

Chemistry - A European Journal, Год журнала: 2017, Номер 23(64), С. 16115 - 16151

Опубликована: Июнь 22, 2017

Abstract The direct introduction of alkenyl groups into the indole framework avoiding its preliminary functionalization can be carried out using different synthetic strategies. Transition‐metal complexes facilitate C−H activation indoles or alkenes allowing an efficient Csp 2 ‐ bond formation. hydroindolation alkynes catalyzed by same metal various acidic promoters also pursued for alkenylation process. Conjugate addition electron‐poor and condensation carbonyl derivatives with are interest this purpose. regiochemical control exploited intrinsic C‐3 reactivity ring. a suitable directing group at nitrogen atom allows preparation C‐2 alkenylated transition reactions. This review collects fundamental contributions in field reported literature during last fifteen years.

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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