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

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(24), P. 17479 - 17646

Published: Oct. 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

Language: Английский

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Single Electron Activation of Aryl Carboxylic Acids

iScience, Journal Year: 2020, Volume and Issue: 23(7), P. 101266 - 101266

Published: June 12, 2020

Aryl carboxylic acids are stable and readily available in great structural diversity both from natural well-established synthetic procedures, which make them promising starting materials organic synthesis. The conversion of benzoic into high-value molecules is importance have gained much interest chemists. recent development single-electron (1e−) activation strategy has been esteemed as a complementary method for the transformation acids. In this context, carboxylate groups can be selectively transferred reactive aryl radical, acyl radical by electrocatalysis, photocatalysis, or presence some SET oxidants. Based on these species, remarkable advancements achieved rapid formation various chemical bonds over past 10 years. review, we summarize advances single electron acids, with an emphasis reaction scope, catalytic system, limitation, underlying mechanism.

Language: Английский

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Highly Diastereo- and Enantioselective Synthesis of Tetrahydrobenzo[b]azocines via Palladium-Catalyzed [4 + 4] Cycloaddition

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(5), P. 2684 - 2690

Published: Feb. 12, 2021

The construction of N-heterocyclic eight-membered rings with good regio-, stereo-, and enantioselective control remains a formidable challenge in asymmetric catalysis. Herein, we report palladium-catalyzed [4 + 4] cycloaddition anthranils γ-methylidene-δ-valerolactones the presence Et3B, delivering highly functionalized tetrahydrobenzo[b]azocine derivatives high efficiency diastereoselectivities enantioselectivities (up to 92% yield, 20:1 dr, 99% ee). Moreover, complex substrates derived from natural products (bearing different functionalities) could be well-tolerated catalytic cycloaddition. mild reaction conditions, conjunction broad substrate scope (44 examples), level stereoselectivity, provide great potential build azocine compounds simple building blocks.

Language: Английский

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NiH-Catalyzed Hydroamination/Cyclization Cascade: Rapid Access to Quinolines

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(13), P. 7772 - 7779

Published: June 13, 2021

Despite the significant success of metal-H-catalyzed hydroamination methodologies, considerable limitations still exist in selective alkynes, especially for terminal alkynes. Herein, we develop a highly efficient NiH catalytic system that activates readily available alkynes cascade hydroamination/cyclization reaction with anthranils. This mild, operationally simple protocol is amenable to wide array including and internal, aryl alkyl, electron-deficient electron-rich ones, delivering structurally diverse quinolines useful excellent yields (>80 examples, up 93% yield). The utility this procedure exhibited late-stage functionalization several natural products concise synthesis an antitumor molecule graveolinine triplex DNA intercalator. Preliminary mechanistic experiments suggest alkenylnickel-mediated alkyne intramolecular cyclization/aromatization putative enamine intermediates.

Language: Английский

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Radical Transformations towards the Synthesis of Quinoline: A Review

Chemistry - An Asian Journal, Journal Year: 2020, Volume and Issue: 15(24), P. 4153 - 4167

Published: Nov. 2, 2020

Quinoline is considered one of the most ubiquitous heterocycles due to its engaging biological activities and synthetic utility over organic transformations. Over past few decades, numerous reports have been documented in synthesis quinolines. The classical methods including, Skraup, Friedlander, Doebner-von-Miller, Conrad-Limpach, Pfitzinger quinoline synthesis, so forth, these are well-known construct principal scaffold with several advantages limitations. Recently, radical insertion or catalyzed reactions emerged as a powerful efficient tool high atom efficiency step economy. In this concern, minireview mainly focused on developments via reactions. addition, brief description preparation procedure, reactivity, mechanisms also included, where possible. Respectively, quinolines classified summarized based it will help researchers grab information exploration area, Quinolines promising pharmacophores.

Language: Английский

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Divergent synthesis of fused N-heterocyclesviarhodium-catalysed [4 + 2] cyclization of pyrazolidinones with iodonium ylides

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(8), P. 2181 - 2186

Published: Jan. 1, 2022

We developed a catalytic system-controlled tunable strategy for the divergent synthesis of cinnolines and pyrazolo[1,2- ]cinnolines via rhodium-catalyzed [4 + 2] cyclization easily available pyrazolidinones iodonium ylides.

Language: Английский

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Photo-Thermo-Mechanochemical Approach to Synthesize Quinolines via Addition/Cyclization of Sulfoxonium Ylides with 2-Vinylanilines Catalyzed by Iron(II) Phthalocyanine

Organic Letters, Journal Year: 2022, Volume and Issue: 24(5), P. 1146 - 1151

Published: Feb. 3, 2022

A novel photo-thermo-mechanochemical approach to assembling quinolines catalyzed by iron(II) phthalocyanine has been realized for the first time. This transformation features a cost-efficient catalytic system and operational simplicity, is free of solvent, shows good substrate tolerance, providing green alternative existing thermal approaches. Mechanistic experiments demonstrate that in-situ-formed secondary amine may be key intermediate further cyclization/aromatization process.

Language: Английский

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Organic Azides: Versatile Synthons in Transition Metal‐Catalyzed C(sp²)−H Amination/Annulation for N‐Heterocycle Synthesis

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 363(2), P. 411 - 424

Published: Nov. 14, 2020

Abstract Organic azides are highly reactive, which have long established as versatile building blocks in the assembly of structurally diverse N‐containing heterocycles. The conversion organic into high‐value compounds is great importance and a subject enormous current interest. Transition metal‐catalyzed C( sp 2 )−H amination/annulation provides powerful tool for transformation wide range biologically important heterocyclic frameworks. In this review, we aim to summarize recent progress on azides‐mediated N‐heterocycle synthesis enabled by transition metal catalysts. Representative strategies discussed detail, including catalytic systems, reaction scopes, limitations mechanisms. magnified image

Language: Английский

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Recent Progress in the C−N Bond Formation via High‐Valent Group 9 Cp*M(III)‐Catalyzed Directed sp² C−H Activation

Asian Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 9(11), P. 1701 - 1717

Published: Aug. 13, 2020

Abstract The presence of nitrogen atom in a wide variety organic compounds called for the use powerful C−H activation strategy C−N bond formation. Pentamethylcyclopentadienyl (Cp*) based, high‐valent, group 9 transition‐metal complexes have shown great potential as catalysts activation/functionalization over years. This minireview summarizes recent progress made context formation via catalytic (sp 2 )C−H with Cp*M(III) (M=Co, Rh and Ir) catalysts. A general plausible mechanism is briefly discussed at beginning, then results are arranged according to metal cobalt, rhodium iridium, respectively.

Language: Английский

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Transition Metal‐Mediated Functionalization of Isoxazoles: A Review

Asian Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 10(12), P. 3127 - 3165

Published: Oct. 11, 2021

Abstract Isoxazoles are an important class of heterocycles with nitrogen and oxygen in a 1,2‐relationship. They find wide applications synthetic organic chemistry part several drug molecules. Since the last two decades, great progress has been achieved synthesis functionalization isoxazoles, which transition metal catalysis played pivotal role towards achieving this goal. In particular, (TM)‐mediated site‐selective functionalizations isoxazoles retain pharmacologically synthetically valuable isoxazole skeleton, highly appealing. This comprehensive review is solely dedicated to TM‐mediated wherein we have included as directing groups (DG) for TM‐catalyzed C−H reactions, direct functionalization, along cross‐coupling reactions annulation finally ring‐opening under TM‐catalysis also discussed. Also, incorporated discussions on reaction designs, their advantages limitations, mechanistic details challenges that need be addressed inspire medicinal chemists explore new arenas make use key scaffold.

Language: Английский

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