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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C–H Activation: Toward Sustainability and Applications

ACS Central Science, Год журнала: 2021, Номер 7(2), С. 245 - 261

Опубликована: Фев. 2, 2021

Since the definition of "12 Principles Green Chemistry" more than 20 years ago, chemists have become increasingly mindful need to conserve natural resources and protect environment through judicious choice synthetic routes materials. The direct activation functionalization C–H bonds, bypassing intermediate functional group installation is, in abstracto, step atom economic, but numerous factors still hinder sustainability large-scale applications. In this Outlook, we highlight research areas seeking overcome challenges activation: pursuit abundant metal catalysts, avoidance static directing groups, replacement oxidants, introduction bioderived solvents. We close by examining progress made subfield aryl borylation from its origins, highly efficient precious Ir-based systems, emerging 3d catalysts. future growth field will depend on industrial uptake, thus urge researchers strive toward sustainable activation.

Язык: Английский

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(Pentamethylcyclopentadienyl)cobalt(III)‐Catalyzed C–H Bond Functionalization: From Discovery to Unique Reactivity and Selectivity

Advanced Synthesis & Catalysis, Год журнала: 2017, Номер 359(8), С. 1245 - 1262

Опубликована: Март 16, 2017

Abstract High‐valent (pentamethylcyclopentadienyl)cobalt(III) [Cp*Co(III)] catalysts were found as inexpensive alternatives to (pentamethylcyclopentadienyl)rhodium(III) [Cp*Rh(III)] in the field of C—H bond functionalization, and applied a variety transformations. In this review, after discovery early examples Cp*Co(III)‐catalyzed functionalization are summarized, unique reactivity selectivity Cp*Co(III) differences between cobalt rhodium catalysis intensively discussed. Such assumed be caused by lower electronegativity, hard nature, smaller ionic radius cobalt. magnified image

Язык: Английский

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Intermolecular radical carboamination of alkenes

Chemical Society Reviews, Год журнала: 2020, Номер 49(6), С. 1790 - 1811

Опубликована: Янв. 1, 2020

Vicinal alkene carboamination is a highly efficient and practical synthetic strategy for the straightforward preparation of diverse valuable amine derivatives starting from simple compounds. During last decade that approach has found continuous research interests various methods have been developed using transition-metal catalysis. Driven by renaissance radical chemistry, intermolecular comprising C-C bond C-N forming step intensively investigated recently culminating in novel strategies improved protocols which complement existing methodologies. Radical can be achieved via three different reaction modes. Such cascades proceed through N-radical addition to an with subsequent formation leading 2,1-carboamination products. Alternatively, installed prior initial C-radical β-amination resulting 1,2-carboamination. The third mode comprises single electron oxidation corresponding cation gets trapped N-nucleophile cascade terminated formation. In this review, conceptual approaches will discussed examples recent literature presented. Further, reader get insights into mechanism transformations.

Язык: Английский

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Full Selectivity Control in Cobalt(III)‐Catalyzed C−H Alkylations by Switching of the C−H Activation Mechanism

Angewandte Chemie International Edition, Год журнала: 2017, Номер 56(35), С. 10378 - 10382

Опубликована: Июнь 21, 2017

Selectivity control in hydroarylation-based C-H alkylation has been dominated by steric interactions. A conceptually distinct strategy that exploits the programmed switch activation mechanism means of cobalt catalysis is presented, which sets stage for convenient alkylations with unactivated alkenes. Detailed mechanistic studies provide compelling evidence a programmable from linear-selective ligand-to-ligand hydrogen transfer to branched-selective base-assisted internal electrophilic-type substitution.

Язык: Английский

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C–H functionalization by high-valent Cp*Co(iii) catalysis

Chemical Communications, Год журнала: 2017, Номер 53(22), С. 3165 - 3180

Опубликована: Янв. 1, 2017

Significant progress has been accomplished in directed C–H functionalization through the use of earth-abundant and inexpensive first-row transition metals.

Язык: Английский

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Catalytic Intermolecular Carboamination of Unactivated Alkenes via Directed Aminopalladation

Journal of the American Chemical Society, Год журнала: 2017, Номер 139(32), С. 11261 - 11270

Опубликована: Июль 20, 2017

An intermolecular 1,2-carboamination of unactivated alkenes proceeding via a Pd(II)/Pd(IV) catalytic cycle has been developed. To realize this transformation, cleavable bidentate directing group is used to control the regioselectivity aminopalladation and stabilize resulting organopalladium(II) intermediate, such that oxidative addition carbon electrophile outcompetes potential β-hydride elimination. Under optimized reaction conditions, broad range nitrogen nucleophiles electrophiles are compatible coupling partners in reaction, affording moderate high yields. The products can be easily converted free γ-amino acids γ-lactams, both which common structural motifs found drug molecules bioactive compounds. Reaction kinetics DFT calculations shed light on mechanism explain empirically observed reactivity trends.

Язык: Английский

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Enantioselective Cobalt(III)‐Catalyzed C−H Activation Enabled by Chiral Carboxylic Acid Cooperation

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(47), С. 15425 - 15429

Опубликована: Окт. 6, 2018

The enantioselective cobalt(III)-catalyzed C-H alkylation was achieved through the design of a novel chiral acid. activation characterized by high position-, regio- and enantio-control under exceedingly mild reaction conditions. Thereby, robust cooperative cobalt(III) catalysis proved tolerant valuable electrophilic functional groups, including hydroxyl, bromo, iodo substituents. Mechanistic studies revealed considerable additive effect on kinetics negative non-linear-effect.

Язык: Английский

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Bifunctional reagents in organic synthesis

Nature Reviews Chemistry, Год журнала: 2021, Номер 5(5), С. 301 - 321

Опубликована: Апрель 12, 2021

Язык: Английский

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Photosensitized Intermolecular Carboimination of Alkenes through the Persistent Radical Effect

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(8), С. 3172 - 3177

Опубликована: Дек. 3, 2019

Abstract An intermolecular, two‐component vicinal carboimination of alkenes has been accomplished by energy transfer catalysis. Oxime esters alkyl carboxylic acids were used as bifunctional reagents to generate both and iminyl radicals. Subsequently, addition the radical an alkene generates a transient for selective radical–radical cross‐coupling with persistent radical. Furthermore, this process provides direct access aliphatic primary amines α‐amino simple hydrolysis.

Язык: Английский

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