C–H activation

Nature Reviews Methods Primers, Год журнала: 2021, Номер 1(1)

Опубликована: Июнь 17, 2021

Язык: Английский

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Toolbox for Distal C–H Bond Functionalizations in Organic Molecules

Chemical Reviews, Год журнала: 2021, Номер 122(6), С. 5682 - 5841

Опубликована: Окт. 18, 2021

Transition-metal-catalyzed C–H activation has developed a contemporary approach to the omnipresent area of retrosynthetic disconnection. Scientific researchers have been tempted take help this methodology plan their synthetic discourses. This paradigm shift helped in development industrial units as well, making synthesis natural products and pharmaceutical drugs step-economical. In vast zone bond activation, functionalization proximal bonds gained utmost popularity. Unlike bonds, distal is more strenuous requires distinctly specialized techniques. review, we compiled various methods adopted functionalize mechanistic insights within each these procedures, scope methodology. With give complete overview expeditious progress made field organic chemistry while also highlighting its pitfalls, thus leaving open for further modifications.

Язык: Английский

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Transition-Metal-Catalyzed, Coordination-Assisted Functionalization of Nonactivated C(sp³)–H Bonds

Chemical Reviews, Год журнала: 2021, Номер 121(24), С. 14957 - 15074

Опубликована: Окт. 29, 2021

Transition-metal-catalyzed, coordination-assisted C(sp3)–H functionalization has revolutionized synthetic planning over the past few decades as use of these directing groups allowed for increased access to many strategic positions in organic molecules. Nonetheless, several challenges remain preeminent, such requirement high temperatures, difficulty removing or converting groups, and, although metals provide some reactivity, employing outside palladium. This review aims give a comprehensive overview coordination-assisted, transition-metal-catalyzed, direct nonactivated bonds by covering literature since 2004 order demonstrate current state-of-the-art methods well limitations. For clarity, this been divided into nine sections transition metal catalyst with subdivisions type bond formation. Synthetic applications and reaction mechanism are discussed where appropriate.

Язык: Английский

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Photocatalytic Late-Stage C–H Functionalization

Chemical Reviews, Год журнала: 2023, Номер 123(8), С. 4237 - 4352

Опубликована: Янв. 24, 2023

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C–H functionalization approaches that make use low energy photons as a controllable source. Compared to traditional strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- chemoselectivities. Merging compelling benefits with workflow offers potentially unmatched arsenal tackle drug development campaigns beyond. This Review highlights photocatalytic strategies small-molecule drugs, agrochemicals, natural products, classified according targeted bond newly formed one. Emphasis is devoted identifying, describing, comparing main mechanistic scenarios. draws critical comparison between established ionic chemistry photocatalyzed radical-based manifolds. aims establish current state-of-the-art illustrate key unsolved challenges be addressed in future. authors aim introduce general readership functionalization, specialist practitioners evaluation methodologies, potential for improvement, future uncharted directions.

Язык: Английский

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Synergistic Dual Transition Metal Catalysis

Chemical Reviews, Год журнала: 2020, Номер 120(24), С. 13382 - 13433

Опубликована: Ноя. 29, 2020

Synergistic catalysis, a type of plural catalysis which utilizes at least two different catalysts to enable reaction between separately activated substrates, has unlocked plethora previously unattainable transformations and novel chemical reactivity. Despite the appreciable utility synergistic specific examples involving transition metals have been limited, as ensuring judicious choice parameters prevent deactivation catalysts, undesirable monocatalytic event(s) leading side products, or premature termination other potentially troublesome outcomes present formidable challenge. Excluding those driven by photocatalytic mechanisms, this review will highlight reported reactions that make use simultaneous catalytic cycles metal catalysts.

Язык: Английский

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Recent advances in transition-metal-catalyzed carbene insertion to C–H bonds

Chemical Society Reviews, Год журнала: 2022, Номер 51(7), С. 2759 - 2852

Опубликована: Янв. 1, 2022

C-H functionalization has been emerging as a powerful method to establish carbon-carbon and carbon-heteroatom bonds. Many efforts have devoted transition-metal-catalyzed direct transformations of Metal carbenes generated in situ from transition-metal compounds diazo or its equivalents are usually applied the transient reactive intermediates furnish catalytic cycle for new C-C C-X bond formation. Using this strategy unactivated simple alkanes complex molecules can be further functionalized transformed multi-functionalized compounds. In area, carbene insertion bonds paid continuous attention. Diverse catalyst design strategies, synthetic methods, potential applications developed. This critical review will summarize advance dated up July 2021, by categories aliphatic C(sp3)-H, aryl (aromatic) C(sp2)-H, heteroaryl (heteroaromatic) C(sp2)-H bonds, alkenyl alkynyl C(sp)-H, well asymmetric more coverage given recent work. Due rapid development future directions topic also discussed. give authors an overview chemistry with focus on systems

Язык: Английский

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3d metallaelectrocatalysis for resource economical syntheses

Chemical Society Reviews, Год журнала: 2020, Номер 49(13), С. 4254 - 4272

Опубликована: Янв. 1, 2020

This review summarizes key developments in 3d metallaelectrocatalysis the context of resource economy molecular syntheses.

Язык: Английский

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2-(Pyridin-2-yl)isopropyl (PIP) Amine: An Enabling Directing Group for Divergent and Asymmetric Functionalization of Unactivated Methylene C(sp³)–H Bonds

Accounts of Chemical Research, Год журнала: 2021, Номер 54(12), С. 2750 - 2763

Опубликована: Май 21, 2021

ConspectusDirecting group (DG) assistance provides a good solution to the problems of reactivity and selectivity, two fundamental challenges in C(sp3)–H activation. However, activation unbiased methylene bonds remains challenging due high heterolytic bond dissociation energy substantial steric hindrance. Two main strategies have been developed thus far, that is, use strongly coordinating bidentate DG pioneered by Daugulis weakly monodentate accelerated pyridine-type ligands, as disclosed Yu. The seminal work sparked significant interest application monoanionic auxiliary aliphatic C–H reactions. Our research has focused on enabling divergent functionalization enantiotopic differentiation unactivated bonds. Inspired structure 8-aminoquinoline accelerating effect gem-dimethyl moiety cyclometalations, we 2-(pyridine-yl)isopropyl (PIP) amine consisting pyridyl group, moiety, an amino which enabled β-methylene forge C–O, C–N, C–C, C–F with palladium catalysts. exclusive β-selectivity was ascribed preferential formation kinetically favored [5,5]-bicyclic palladacycle intermediates. DFT calculations revealed well-designed responsible for lowered compressed bite angle key transition state related cleavage.More recently, combination PIP axially chiral ligands found promote asymmetric bonds, topic area be addressed. different types namely, non-C2-symmetric phosphoric acids (CPAs) 3,3′-disubstituted BINOLs, developed. former Pd(II)-catalyzed inter- intramolecular arylation enantioselectivity, whereas latter promoted series reactions, such alkynylation, arylation, alkenylation/aza-Wacker cyclization, amidation. unexpectedly stereocontrol compared other DGs might attributable communication between ligand amine. Thus BINOL is arguably most general strategy Finally, ease installation removal under mild conditions synthetic applications are described.

Язык: Английский

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Photochemical and Electrochemical Strategies towards Benzylic C−H Functionalization: A Recent Update

Advanced Synthesis & Catalysis, Год журнала: 2021, Номер 363(7), С. 1810 - 1834

Опубликована: Фев. 16, 2021

Abstract Transition metal‐catalysed processes have been widely used for the functionalization of inert C−H bonds. Strategies benzylic position having a relatively weak bond (bond dissociation energy∼ 80–90 kcal/mol) differ from aliphatic and aromatic positions with stronger The recent advances in direct activation through generation C( sp 3 ) radicals demonstrated potential electrochemistry photochemistry as means constructing new chemical This review will cover progress organic radical strategies employing sustainable tools. In addition, mechanistic details typical reactions included which, turn, help researchers to look at this promising area different perspective towards discoveries often hidden opportunities. magnified image

Язык: Английский

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Metallaphotoredox catalysis for sp³C–H functionalizations through hydrogen atom transfer (HAT)

Chemical Society Reviews, Год журнала: 2023, Номер 52(12), С. 4099 - 4120

Опубликована: Янв. 1, 2023

sp 3 C–H functionalizations under the combination of photocatalytic HAT and transition metal catalysis.

Язык: Английский

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