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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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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NiH-catalysed proximal-selective hydroalkylation of unactivated alkenes and the ligand effects on regioselectivity

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Апрель 7, 2022

Abstract Alkene hydrocarbonation reactions have been developed to supplement traditional electrophile-nucleophile cross-coupling reactions. The branch-selective hydroalkylation method applied a broad range of unactivated alkenes remains challenging. Herein, we report NiH-catalysed proximal-selective access β- or γ-branched alkyl carboxylic acids and β-, γ- δ-branched amines. A iodides bromides with different functional groups can be installed excellent regiocontrol availability for site-selective late-stage functionalization biorelevant molecules. Under modified reaction conditions NiCl 2 (PPh 3 ) as the catalyst, migratory takes place provide (rather than γ-) branched products. keys success are use aminoquinoline picolinamide suitable directing combined experimental computational studies ligand effects on regioselectivity detailed mechanisms.

Язык: Английский

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Synthetic applications of hydride abstraction reactions by organic oxidants

Chemical Society Reviews, Год журнала: 2022, Номер 51(13), С. 5660 - 5690

Опубликована: Янв. 1, 2022

Organic oxidants, including quinones, oxoammonium ions, and trityl cations, abstract hydride ions to form carbocations. This review describes the mechanistic foundations for these processes vast array of their applications in synthesis.

Язык: Английский

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Strategic application of C–H oxidation in natural product total synthesis

Nature Reviews Chemistry, Год журнала: 2023, Номер 7(11), С. 783 - 799

Опубликована: Сен. 20, 2023

Язык: Английский

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Palladium(II)-Catalyzed Enantioselective Functionalization of C(sp³)—H Bonds^★

Acta Chimica Sinica, Год журнала: 2023, Номер 81(11), С. 1522 - 1522

Опубликована: Янв. 1, 2023

Chiral molecules are ubiquitous in nature and play an important role natural products, pharmaceuticals, agriculture, advanced materials, as well living organisms.Therefore, the development of efficient strategies to enable facile construction enantiopure chiral compounds atom-and step-economical manner is great importance.The enantioselective functionalization C-H bonds without multi-steps transformation arguably one most powerful straightforward fulfill this goal.This emerging research field has been rapidly developed with innovation various catalysts and/or ligands recent years.In particular, significant advances have achieved palladium-catalyzed C(sp 3 )-H bonds, streamlining concise from readily available hydrocarbon feedstocks.The stereoselective assistance ligand form a palladacycle intermediate, which could be transformed into chemical functionalized compounds, attracted tremendous attention.Thus, perspective summarizes on palladium(II)-catalyzed via asymmetric palladation.According type classified several sections, including methyl methylene constrained cycloalkanes, adjacent α-heteroatom, benzylic unbiased bonds.The emphasis focuses discussion philosophy developing novel mode stereocontrol.The remaining limitations challenges regarding chemo-and control also discussed.Further new catalytic systems expected address these issues expands scope synthetic strategy.We anticipate that might inspire more efforts strategy find wide applications synthesis complicated molecules, such products drugs.

Язык: Английский

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Asymmetric synthesis of chiral organosilicon compounds via transition metal-catalyzed stereoselective C–H activation and silylation

Chemical Communications, Год журнала: 2021, Номер 57(67), С. 8250 - 8263

Опубликована: Янв. 1, 2021

Central, axial, planar, or helical chiral silylated compounds have been asymmetrically synthesized via transition metal-catalyzed stereoselective C–H activation/silylation.

Язык: Английский

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Transition-metal-catalyzed site-selective γ- and δ-C(sp3)–H functionalization reactions

Chem, Год журнала: 2022, Номер 8(5), С. 1254 - 1360

Опубликована: Май 1, 2022

Язык: Английский

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Synthesis of C‐Oligosaccharides through Versatile C(sp³)−H Glycosylation of Glycosides

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(11)

Опубликована: Янв. 11, 2022

Abstract C‐ oligosaccharides are pharmacologically relevant because they more hydrolysis‐resistant than O ‐oligosaccharides. Despite indisputable advances, C ‐oligosaccharides continue to be underdeveloped, likely due a lack of efficient and selective strategies for the assembly interglycosidic C−C linkages. In contrast, we, herein, report versatile robust strategy synthesis structurally complex via catalyzed C(sp 3 )−H activations. Thus, wealth (2→1)‐ (1→1)‐ becomes readily available by palladium‐catalyzed glycoside glycosylation. The isolation key palladacycle intermediates experiments with isotopically‐labeled compounds identified trans‐ stereoselectivity activation manifold was likewise exploited diversification furanoses, pyranoses disaccharides.

Язык: Английский

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Remote C−H Glycosylation by Ruthenium(II) Catalysis: Modular Assembly ofmeta‐C‐Aryl Glycosides

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(42)

Опубликована: Июль 25, 2022

Abstract The prevalence of C ‐aryl glycosides in biologically active natural products and approved drugs has long motivated the development efficient strategies for their selective synthesis. Cross‐couplings have been frequently used, but largely relied on palladium catalyst with prefunctionalized substrates, while ruthenium‐catalyzed glycoside preparation thus far proven elusive. Herein, we disclose a versatile ruthenium(II)‐catalyzed meta ‐C−H glycosylation to access ‐ from readily available glycosyl halide donors. robustness ruthenium catalysis was reflected by mild reaction conditions, outstanding levels anomeric selectivity exclusive ‐site‐selectivity.

Язык: Английский

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