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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Contemporary synthetic strategies in organofluorine chemistry

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

Опубликована: Июль 8, 2021

Язык: Английский

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Efficient Synthesis of Sulfur-Stereogenic Sulfoximines via Ru(II)-Catalyzed Enantioselective C–H Functionalization Enabled by Chiral Carboxylic Acid

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(18), С. 6810 - 6816

Опубликована: Апрель 28, 2021

Ru(II)-catalyzed enantioselective C-H functionalization involving an enantiodetermining cleavage step remains undeveloped. Here we describe a activation/annulation of sulfoximines with α-carbonyl sulfoxonium ylides using novel class chiral binaphthyl monocarboxylic acids as ligands, which can be easily and modularly prepared from 1,1'-binaphthyl-2,2'-dicarboxylic acid. A broad range sulfur-stereogenic were in high yields excellent enantioselectivities (up to 99% yield ee) via desymmetrization, kinetic resolution, parallel resolution. Furthermore, the resolution products transformed sulfoxides key intermediates for kinase inhibitors.

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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Stereoselective construction of atropisomers featuring a C–N chiral axis

Green Synthesis and Catalysis, Год журнала: 2022, Номер 3(2), С. 117 - 136

Опубликована: Янв. 4, 2022

Atropisomeric C–N compounds belong to an important class of axially chiral compounds. However, whereas the asymmetric synthesis biaryl atropisomers have been well established, general and efficient strategies access single enantiomers are still rare. Until recently, innovative methods developed, providing new opportunities for highly stereoselective this vital atropisomers. Herein, we comprehensively summarize development in emerging field give some insights into future advance. Emphasis is placed on synthetic strategies.

Язык: Английский

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Recent Advances in Alkenyl sp² C–H and C–F Bond Functionalizations: Scope, Mechanism, and Applications

Chemical Reviews, Год журнала: 2022, Номер 122(24), С. 17479 - 17646

Опубликована: Окт. 14, 2022

Alkenes and their derivatives are featured widely in a variety of natural products, pharmaceuticals, advanced materials. Significant efforts have been made toward the development new practical methods to access this important class compounds by selectively activating alkenyl C(sp2)–H bonds recent years. In comprehensive review, we describe state-of-the-art strategies for direct functionalization sp2 C–H C–F until June 2022. Moreover, metal-free, photoredox, electrochemical also covered. For clarity, review has divided into two parts; first part focuses on currently available using different alkene as starting materials, second describes bond easily accessible gem-difluoroalkenes material. This includes scope, limitations, mechanistic studies, stereoselective control (using directing groups well metal-migration strategies), applications complex molecule synthesis where appropriate. Overall, aims document considerable advancements, current status, emerging work critically summarizing contributions researchers working fascinating area is expected stimulate novel, innovative, broadly applicable functionalizations coming

Язык: Английский

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Transition Metal-Catalyzed Biaryl Atropisomer Synthesis via a Torsional Strain Promoted Ring-Opening Reaction

Accounts of Chemical Research, Год журнала: 2022, Номер 55(12), С. 1620 - 1633

Опубликована: Июнь 1, 2022

ConspectusArising from the restricted rotation of a single bond caused by steric or electronic effects, atropisomerism is one few fundamental categories for molecules to manifest their three-dimensional characters into which axially chiral biaryl compounds fall. Despite widespread occurrence skeletons in natural products, bioactive molecules, and ligands/organocatalysts, catalytic asymmetric methods synthesis these structures still lag behind demand. Major challenges preparation biaryls include accessing highly sterically hindered variants while controlling stereoselectivity. A couple useful strategies have emerged direct last two decades.Recently, we engaged atropisomers via transition metal catalysis, including ring-openings dibenzo cyclic compounds. During studies, serendipitously discovered that substituents adjacent axis cause be distorted minimize repulsion. The display higher reactivity ring-opening reactions than non-distorted molecules. In other words, torsional strain can promote reaction. On basis this concept, successfully realized reaction diaryliodoniums, silanes, 9H-fluoren-9-ols, delivered several differently substituted ortho tetra-substituted high enantioselectivity. not only activates substrates toward under mild conditions but also changes chemoselectivity bond-breaking events. palladium-catalyzed carboxylation S-aryl dibenzothiophenium, inversed selectivity exocyclic C–S cleavage reaction.In Account, summarize our studies on copper-, rhodium-, as collection straightforward with enantiopurity above-mentioned strain-promoted coupling strategy. part, energies are discussed aid density functional theory (DFT) calculations.

Язык: Английский

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Chiral Carboxylic Acid Assisted Enantioselective C–H Activation with Achiral Cp^xM^III (M = Co, Rh, Ir) Catalysts

ACS Catalysis, Год журнала: 2021, Номер 11(11), С. 6455 - 6466

Опубликована: Май 17, 2021

Enantioselective C–H functionalization is a powerful tool for synthesizing chiral molecules. In the past few years, combination of high-valent group 9 metals with achiral Cpx ligands and carboxylic acids (CCA) has emerged as promising catalytic system to enable selective cleavage enantiotopic bonds. This Perspective summarizes background, catalyst design, applied reactions in detail, followed by discussion future directions.

Язык: Английский

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