Nickel Catalysts/N,N′-Bidentate Directing Groups: An Excellent Partnership in Directed C–H Activation Reactions

Chemistry Letters, Год журнала: 2015, Номер 44(4), С. 410 - 421

Опубликована: Янв. 26, 2015

Abstract This review focuses on chelation-assisted regioselective C–H activation with C–C or/and C–N bond formation using nickel(0) or -(II) as the catalysts, where bidentate directing groups play a key role in successful transformation. A 2-pyridinylmethylamine an 8-aminoquinoline moiety are more powerful auxiliaries among examined.

Язык: Английский

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Site-selective and stereoselective functionalization of unactivated C–H bonds

Nature, Год журнала: 2016, Номер 533(7602), С. 230 - 234

Опубликована: Май 10, 2016

Язык: Английский

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Rhodium‐Catalyzed C(sp²)‐ or C(sp³)−H Bond Functionalization Assisted by Removable Directing Groups

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(25), С. 8304 - 8329

Опубликована: Окт. 12, 2018

Abstract In recent years, transition‐metal‐catalyzed C−H activation has become a key strategy in the field of organic synthesis. Rhodium complexes are widely used as catalysts variety functionalization reactions because their high reactivity and selectivity. The availability number rhodium various oxidation states enables diverse reaction patterns to be obtained. Regioselectivity, an important issue chemistry, can accomplished by using directing group assist reaction. However, obtain target functionalized compounds, it is also necessary use that easily removed. A wide range directed catalyzed have been reported date. this Review, we discuss Rh‐catalyzed aided removable such phenol, amine, aldehyde, ketones, ester, acid, sulfonic N‐heteroaromatic derivatives.

Язык: Английский

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Recent advances in positional-selective alkenylations: removable guidance for twofold C–H activation

Organic Chemistry Frontiers, Год журнала: 2017, Номер 4(7), С. 1435 - 1467

Опубликована: Янв. 1, 2017

Recent advances in transition-metal catalyzed positional-selective alkenylations via twofold C–H activation directed by removable or traceless directing groups are reviewed.

Язык: Английский

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Remote para-C–H Functionalization of Arenes by a D-Shaped Biphenyl Template-Based Assembly

Journal of the American Chemical Society, Год журнала: 2015, Номер 137(37), С. 11888 - 11891

Опубликована: Сен. 11, 2015

Site-selective C–H functionalization has emerged as an efficient tool in simplifying the synthesis of complex molecules. Most often, directing group (DG)-assisted metallacycle formation serves strategy to ensure promising regioselectivity. A wide variety ortho- and meta-C–H functionalizations stand examples this regard. Yet despite significant progress, DG-assisted selective para-C–H arenes remained unexplored, mainly because it involves a geometrically constrained metallacyclic transition state. Here we report easily recyclable, novel Si-containing biphenyl-based template that directs distal p-C–H bond toluene by forming D-shaped assembly. This DG allows required flexibility support oversized pre-transition By overcoming electronic steric bias, para-olefination acetoxylation were successfully performed while undermining o- m-C–H activation. The applicability biphenyl template-based is demonstrated synthesizing various

Язык: Английский

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Methodologies and Strategies for Selective Borylation of C–Het and C–C Bonds

Chemical Reviews, Год журнала: 2020, Номер 120(15), С. 7348 - 7398

Опубликована: Июнь 29, 2020

Organoborons have emerged as versatile building blocks in organic synthesis to achieve molecular diversity and carboxylic acid bioisosteres with broad applicability drug discovery. Traditionally, these compounds are prepared by the substitution of Grignard/lithium reagents electrophilic boron species Brown hydroboration. Recent developments provided new routes for efficient preparation organoborons applying reactions using chemical feedstocks leaving groups. As compared previous methods that used halides (I, Br, Cl), direct borylation less reactive C–Het C–C bonds has become highly important get efficiency functional-group compatibility. This Review aims provide a comprehensive overview this topic, including (1) C–F bond borylation, (2) C–O (3) C–S (4) C–N (5) borylation. Considerable attention is given strategies mechanisms involved. We expect will inspire chemists discover more transformations expand field.

Язык: Английский

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Site-selective and stereoselective functionalization of non-activated tertiary C–H bonds

Nature, Год журнала: 2017, Номер 551(7682), С. 609 - 613

Опубликована: Ноя. 1, 2017

Язык: Английский

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Synthesis of Axially Chiral Biaryls through Sulfoxide‐Directed Asymmetric Mild CH Activation and Dynamic Kinetic Resolution

Angewandte Chemie International Edition, Год журнала: 2014, Номер 53(50), С. 13871 - 13875

Опубликована: Окт. 10, 2014

Abstract A mild and robust direct CH functionalization strategy has been applied to the synthesis of axially chiral biaryls. Such an efficient stereoselective transformation occurs through original dynamic kinetic resolution pathway enabling conversion diastereomeric mixtures non‐prefunctionalized substrates into atropisomerically pure, highly substituted biaryl scaffolds. The main feature this is use enantiopure sulfoxide as both auxiliary traceless directing group. potential newly synthesized biaryls valuable building blocks further illustrated.

Язык: Английский

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Electroremovable Traceless Hydrazides for Cobalt-Catalyzed Electro-Oxidative C–H/N–H Activation with Internal Alkynes

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(25), С. 7913 - 7921

Опубликована: Май 29, 2018

Electrochemical oxidative C–H/N–H activations have been accomplished with a versatile cobalt catalyst in terms of [4 + 2] annulations internal alkynes. The electro-oxidative C–H activation manifold proved viable an undivided cell setup under exceedingly mild reaction conditions at room temperature using earth-abundant catalysts. electrochemical catalysis prevents the use transition metal oxidants catalysis, generating H2 as sole byproduct. Detailed mechanistic studies provided strong support for facile cobaltation by initially formed cobalt(III) catalyst. subsequent alkyne migratory insertion was interrogated mass spectrometry and DFT calculations, providing formation key seven-membered cobalta(III) cycle regioselective fashion. Key to success unprecedented alkynes represented N-2-pyridylhydrazides, which we developed traceless electrocleavage strategy electroreductive samarium temperature.

Язык: Английский

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Palladium(II)‐Catalyzed meta‐CH Olefination: Constructing Multisubstituted Arenes through Homo‐Diolefination and Sequential Hetero‐Diolefination

Angewandte Chemie International Edition, Год журнала: 2015, Номер 54(29), С. 8515 - 8519

Опубликована: Июнь 9, 2015

Divinylbenzene derivatives represent an important class of molecular building blocks in organic chemistry and materials science. Reported herein is the palladium-catalyzed synthesis divinylbenzenes by meta-C-H olefination sulfone-based arenes. Successful sequential olefinations a position-selective manner provided novel route for hetero-dialkenylated products, which are difficult to access using conventional methods. Additionally, 1,3,5-trialkenylated compounds can be generated upon successful removal directing group.

Язык: Английский

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