Transition metal-catalyzed C–H bond functionalizations by the use of diverse directing groups

Organic Chemistry Frontiers, Journal Year: 2015, Volume and Issue: 2(9), P. 1107 - 1295

Published: Jan. 1, 2015

In this review, a summary of transition metal-catalyzed C–H activation by utilizing the functionalities as directing groups is presented.

Language: Английский

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Weakly Coordinating Directing Groups for Ruthenium(II)‐ Catalyzed CH Activation

Advanced Synthesis & Catalysis, Journal Year: 2014, Volume and Issue: 356(7), P. 1461 - 1479

Published: April 30, 2014

Abstract Synthetically useful functional groups, including ketones, amides, carbamates, carboxylic acids, aldehydes or ethers, have been identified as weakly coordinating directing groups in efficient ruthenium(II)‐catalyzed CH functionalizations. This strategy set the stage for versatile bond olefinations, oxygenations, nitrogenations and oxidative alkyne annulations among others. Thereby, step‐economical access to diversely decorated arenes heteroarenes was provided a sustainable fashion. magnified image

Language: Английский

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Recent advances in directed C–H functionalizations using monodentate nitrogen-based directing groups

Organic Chemistry Frontiers, Journal Year: 2014, Volume and Issue: 1(7), P. 843 - 843

Published: May 14, 2014

The use of directing groups has proven to be a successful strategy enhance reactivity and control selectivity in C–H functionalization reactions. In the past decade, multitude new transformations have been explored, several recent reviews discussed group approaches for functionalization. This review focuses specifically on monodentate nitrogen-based published during two years, with aim covering body literature that is complementary existing reviews.

Language: Английский

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Transition metal-catalyzed C–H functionalization of N-oxyenamine internal oxidants

Chemical Society Reviews, Journal Year: 2014, Volume and Issue: 44(5), P. 1155 - 1171

Published: Nov. 24, 2014

The N-oxyenamine internal oxidant gives more chance to investigate the C–H bond activation under mild reaction conditions.

Language: Английский

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Metal‐Catalyzed Annulations through Activation and Cleavage of C−H Bonds

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 55(37), P. 11000 - 11019

Published: June 22, 2016

The exponential increase in the number of catalytic transformations that involve a metal-promoted activation hitherto considered inert C-H bonds is promoting fundamental change field synthetic chemistry. Although most reactions involving activations consist simple functionalizations or additions, recent years have witnessed an upsurge related can be formally as cycloaddition processes. These are particularly appealing from perspective because they allow conversion readily available substrates into highly valuable cyclic products rapid and sustainable manner. In many cases, these annulations formation metallacyclic intermediates resemble those proposed for standard metal-catalyzed cycloadditions unsaturated precursors.

Language: Английский

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Alkenylation of Arenes and Heteroarenes with Alkynes

Chemical Reviews, Journal Year: 2016, Volume and Issue: 116(10), P. 5894 - 5986

Published: April 25, 2016

This review is focused on the analysis of current data new methods alkenylation arenes and heteroarenes with alkynes by transition metal catalyzed reactions, Bronsted/Lewis acid promoted transformations, others. The synthetic potential, scope, limitations, mechanistic problems reactions are discussed. insertion an alkenyl group into aromatic heteroaromatic rings inter- or intramolecular ways provides a route to derivatives styrene, stilbene, chalcone, cinnamic acid, various fused carbo- heterocycles, etc.

Language: Английский

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Rhodium-Catalyzed C–H Activation of Phenacyl Ammonium Salts Assisted by an Oxidizing C–N Bond: A Combination of Experimental and Theoretical Studies

Journal of the American Chemical Society, Journal Year: 2015, Volume and Issue: 137(4), P. 1623 - 1631

Published: Jan. 8, 2015

Rh(III)-catalyzed C–H activation assisted by an oxidizing directing group has evolved to a mild and redox-economic strategy for the construction of heterocycles. Despite success, these coupling systems are currently limited cleavage N–O or N–N bond. Cleavage C–N bond, which allows complementary carbocycle synthesis, is unprecedented. In this article, α-ammonium acetophenones with bond have been designed as substrates under redox-neutral conditions. The α-diazo esters afforded benzocyclopentanones, unactivated alkenes such styrenes aliphatic olefins gave ortho-olefinated acetophenoes. both reactions proceeded broad scope, high efficiency, functional tolerance. Moreover, efficient one-pot diazo realized starting from α-bromoacetophenones triethylamine. reaction mechanism studied combination experimental theoretical methods. particular, three distinct mechanistic pathways scrutinized DFT studies, revealed that occurs via C-bound enolate-assisted concerted metalation–deprotonation rate-limiting. subsequent C–C formation steps, lowest energy pathway involves two rhodium carbene species key intermediates.

Language: Английский

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Cp*Co^III Catalyzed Site‐Selective CH Activation of Unsymmetrical O‐Acyl Oximes: Synthesis of Multisubstituted Isoquinolines from Terminal and Internal Alkynes

Angewandte Chemie International Edition, Journal Year: 2015, Volume and Issue: 54(44), P. 12968 - 12972

Published: Sept. 28, 2015

The synthesis of isoquinolines by site-selective C-H activation O-acyl oximes with a Cp*Co(III) catalyst is described. In the presence this catalyst, various unsymmetrically substituted selectively occurred at sterically less hindered site, and reactions terminal as well internal alkynes afforded corresponding products in up to 98 % yield. Whereas catalyzed system proceeded high site selectivity (15:1 20:1), use Cp*Rh(III) catalysts led low selectivities and/or yields when unsymmetrical were used. Deuterium labeling studies indicate clear difference step under catalysis.

Language: Английский

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Gold‐Catalyzed CH Annulation of Anthranils with Alkynes: A Facile, Flexible, and Atom‐Economical Synthesis of Unprotected 7‐Acylindoles

Angewandte Chemie International Edition, Journal Year: 2015, Volume and Issue: 55(2), P. 794 - 797

Published: Nov. 26, 2015

Abstract The gold‐catalyzed CH annulation of anthranil derivatives with alkynes offers a facile, flexible, and atom‐economical one‐step route to unprotected 7‐acylindoles. An intermediate α‐imino gold carbene, generated by an intermolecular reaction, promotes ortho ‐aryl functionalization afford the target products. transformation proceeds broad range substrates under mild conditions. Moreover, obtained functionalized indole products represent versatile platform for construction diverse indolyl frameworks.

Language: Английский

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Rhodium(III)‐Catalyzed ortho Alkenylation of N‐Phenoxyacetamides with N‐Tosylhydrazones or Diazoesters through CH Activation

Angewandte Chemie International Edition, Journal Year: 2013, Volume and Issue: 53(5), P. 1364 - 1367

Published: Dec. 18, 2013

A coupling reaction of N-phenoxyacetamides with N-tosylhydrazones or diazoesters through Rh(III) -catalyzed CH activation is reported. In this reaction, ortho-alkenyl phenols were obtained in good yields and excellent regio- stereoselectivity. Rh-carbene migratory insertion proposed as the key step mechanism.

Language: Английский

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