Beyond Friedel and Crafts: Directed Alkylation of C−H Bonds in Arenes

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(22), P. 7202 - 7236

Published: Aug. 14, 2018

Abstract Alkylation of arenes is one the most fundamental transformations in chemical synthesis and leads to privileged scaffolds many areas science. Classical methods for introduction alkyl groups are mostly based on Friedel–Crafts reaction, radical additions, metalation, or prefunctionalization arene: these methods, however, suffer from limitations scope, efficiency, selectivity. Moreover, they innate reactivity starting arene, favoring alkylation at a certain position rendering chains other positions much more challenging. This can be addressed by use directing group that facilitates, presence metal catalyst, regioselective C−H bond. These directed alkylations bonds will comprehensively summarized this Review.

Language: Английский

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Cp*M-Catalyzed Direct Annulation with Terminal Alkynes and Their Surrogates for the Construction of Multi-Ring Systems

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(17), P. 9747 - 9757

Published: Aug. 3, 2020

Transition-metal-catalyzed C–H activation followed by oxidative cyclization with unsaturated coupling partners has been a valuable synthetic tool for the multiring molecular scaffolds. This Perspective introduces recent progress on Cp*M-catalyzed (M = Co, Rh, and Ir) direct annulation of functionalized arenes terminal alkynes their equivalents through bond cleavage. The highlighted examples are categorized according to 10 different types reagents used in transformations. representative conditions, selected reaction scope, key mechanistic aspects briefly summarized.

Language: Английский

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Sulfoxonium ylides: simple compounds with chameleonic reactivity

Organic & Biomolecular Chemistry, Journal Year: 2020, Volume and Issue: 18(43), P. 8793 - 8809

Published: Jan. 1, 2020

Sulfur ylides first disclosed in 1930 started to gain more attention the 1960s, thanks mainly studies by Corey and Chaykovsky on their use for preparation of strained rings. More recently, chemistry these compounds has experienced important growth, part due similarity reactivities with diazo compounds. This short review provides an overview great assortment reactions sulfoxonium ylides, outlining a comparison between congeners: sulfonium Insertion reactions, cyclisation ring-opening are highlighted, giving particular catalytic asymmetric methodologies.

Language: Английский

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Sulfoxonium Ylide Derived Metal Carbenoids in Organic Synthesis

Synthesis, Journal Year: 2018, Volume and Issue: 51(03), P. 612 - 628

Published: Dec. 12, 2018

As pioneered by Corey and Chaykovsky, sulfoxonium ylides have had widespread application in organic synthesis for more than a half century. In most of the reactions, were used to react with electrophiles. Under suitable reaction conditions these can generate metal carbenoids nucleophiles. By combining typical reactivity transition-metal catalysis, growing number investigations expanded their synthesis. This review provides an update on preparation applications carbenoid transfer reactions. 1 Introduction 2 Preparation Sulfoxonium Ylides 3 Investigation Carbenoid Formation from Ylide 4 X–H (X = N, O, S, C) Functionalization Reactions 5 Polymerizaton Carbenoids Generated 6 Conclusion Perspective

Language: Английский

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Ru^II-Catalyzed/NH₂-Assisted Selective Alkenyl C–H [5 + 1] Annulation of Alkenylanilines with Sulfoxonium Ylides to Quinolines

Organic Letters, Journal Year: 2019, Volume and Issue: 21(12), P. 4812 - 4815

Published: June 13, 2019

A novel ruthenium-catalyzed [5 + 1] annulation of 2-alkenylanilines with sulfoxonium ylides was developed for the rapid assembly highly functionalized quinolines. This new catalytic process employs challenging but synthetically ideal free amino functionality to achieve alkenyl C–H activation as one-carbon coupling partners. Various 2-acylquinolines could be obtained good yields and excellent functional group tolerance. Moreover, potential synthetic application this methodology exemplified by several chemical transformations.

Language: Английский

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Recent Applications of α-Carbonyl Sulfoxonium Ylides in Rhodium- and Iridium-Catalyzed C–H Functionalizations

Synlett, Journal Year: 2018, Volume and Issue: 30(01), P. 21 - 29

Published: Sept. 5, 2018

Sulfoxonium ylides are a special type of sulfur that serve as new C1 or C2 synthons recently developed for use in C–H functionalization to access acylmethylated cyclized compounds through the formation metal carbene species. Many excellent works have reported syntheses various useful skeletons from these versatile synthons. These developments not previously been completely investigated reviewed. In this review, we summarize recent advances α-carbonyl sulfoxonium functionalizations, including ortho-C–H acylmethylation reactions and activation/cyclization reactions. Table Contents 1 Introduction 2 Ortho-C–H Acylmethylation Reactions 3 Activation/Cyclization 3.1 Anilines Enamines 3.2 Azobenzenes 3.3 N-Methoxybenzamide 3.4 Imines 3.5 N-Azoloimines 3.6 Benzoylacetonitriles 3.7 Benzoyl Ylides 4 Conclusion

Language: Английский

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Synthesis of (2H)-Indazoles through Rh(III)-Catalyzed Annulation Reaction of Azobenzenes with Sulfoxonium Ylides

The Journal of Organic Chemistry, Journal Year: 2018, Volume and Issue: 83(7), P. 4070 - 4077

Published: March 16, 2018

The rhodium(III)-catalyzed C–H functionalization followed by intramolecular annulation reactions between azobenzenes and sulfoxonium ylides is described. This protocol leads to the efficient formation of 3-acyl (2H)-indazoles with a range substrate scope. A high level chemoselectivity functional group tolerance this transformation were also observed.

Language: Английский

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Rhodium(III)-Catalyzed Imidoyl C–H Activation for Annulations to Azolopyrimidines

Organic Letters, Journal Year: 2018, Volume and Issue: 20(8), P. 2464 - 2467

Published: March 27, 2018

Azolopyrimidines are efficiently prepared by direct imidoyl C–H bond activation. Annulations of N-azolo imines with sulfoxonium ylides and diazoketones under redox-neutral conditions alkynes oxidizing provide products various arrangements nitrogen atoms carbon substituents. We have also probed the mechanism this first example Rh(III)-catalyzed activation structural characterization a catalytically competent rhodacycle obtained after kinetic isotope effects.

Language: Английский

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A Catalytic Cross‐Olefination of Diazo Compounds with Sulfoxonium Ylides

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(49), P. 16215 - 16218

Published: Sept. 28, 2018

Abstract A ruthenium‐catalysed cross‐olefination of diazo compounds and sulfoxonium ylides is presented. Our reaction design exploits the intrinsic difference in reactivity as both carbene precursors nucleophiles, which results a highly selective reaction.

Language: Английский

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Construction of (Dihydro)naphtho[1,8-bc]pyrans via Rh(III)-Catalyzed Twofold C–H Activation of Benzoylacetonitriles

Organic Letters, Journal Year: 2018, Volume and Issue: 20(8), P. 2160 - 2163

Published: April 2, 2018

Rh(III)-catalyzed cascade C-H activation of benzoylacetonitriles and annulation with sulfoxonium ylides was realized, leading to selective synthesis naphthols, 2,3-dihydronaphtho[1,8- bc]pyrans, naphtho[1,8- bc]pyrans. This step-economic reaction proceeded efficiently under mild redox-neutral conditions via multiple activations.

Language: Английский

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