Catalytic Functionalization of C(sp²)H and C(sp³)H Bonds by Using Bidentate Directing Groups

Angewandte Chemie International Edition, Journal Year: 2013, Volume and Issue: 52(45), P. 11726 - 11743

Published: Sept. 17, 2013

C-H bonds are ubiquitous in organic compounds. It would, therefore, appear that direct functionalization of substrates by activation would eliminate the multiple steps and limitations associated with preparation functionalized starting materials. Regioselectivity is an important issue because molecules can contain a wide variety bonds. The use directing group largely overcome regiocontrol allowing catalyst to come into proximity targeted A functional groups have been evaluated for as transformation In 2005, Daugulis reported arylation unactivated C(sp(3))-H using 8-aminoquinoline picolinamide bidentate groups, Pd(OAc)2 catalyst. Encouraged these promising results, number transformations since developed systems based on groups. this Review, recent advances area discussed.

Language: Английский

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The Cross‐Dehydrogenative Coupling of CH Bonds: A Versatile Strategy for CC Bond Formations

Angewandte Chemie International Edition, Journal Year: 2013, Volume and Issue: 53(1), P. 74 - 100

Published: Nov. 8, 2013

Abstract Over the last decade, substantial research has led to introduction of an impressive number efficient procedures which allow selective construction CC bonds by directly connecting two different CH under oxidative conditions. Common these methodologies is generation reactive intermediates in situ activation both bonds. This strategy was introduced group Li as cross‐dehydrogenative coupling (CDC) and discloses waste‐minimized synthetic alternatives classic rely on use prefunctionalized starting materials. Review highlights recent progress field C C formations provides a comprehensive overview existing employed methodologies.

Language: Английский

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Formal S_N‐Type Reactions in Rhodium(III)‐Catalyzed CH Bond Activation

Advanced Synthesis & Catalysis, Journal Year: 2014, Volume and Issue: 356(7), P. 1443 - 1460

Published: May 5, 2014

Abstract (Pentamethylcyclopentadienyl)rhodium (RhCp*)‐catalyzed CH transformations have emerged as a prosperous field in bond activation. Recent advances this area significantly focused on the development of new strategies for CC and Cheteroatom formation that are characterized by novel reactivity RhCp* catalyst to undergo formal S N ‐type reactions with electrophilic substrates. This review is intended give an overview rather class RhCp*‐catalyzed transformations, covering recent bond‐forming reactions. The nature reaction partner these functionalization serves guideline throughout article and, combined selected descriptions mechanistic proposals, should emphasize general characteristics within class. magnified image

Language: Английский

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Synthesis of Extended π‐Systems through C–H Activation

Angewandte Chemie International Edition, Journal Year: 2014, Volume and Issue: 54(1), P. 66 - 81

Published: Sept. 26, 2014

Abstract Activation of aromatic CH bonds by a transition metal catalyst has received significant attention in the synthetic chemistry community. In recent years, rapid and site‐selective extension π‐electron systems C–H activation emerged as an ideal methodology for preparing organic materials with extended π‐systems. This Review focuses on recently reported π‐extending reactions directed toward new optoelectronic conjugated materials.

Language: Английский

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Complementary Strategies for Directed C(sp³)−H Functionalization: A Comparison of Transition‐Metal‐Catalyzed Activation, Hydrogen Atom Transfer, and Carbene/Nitrene Transfer

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 57(1), P. 62 - 101

Published: Dec. 5, 2017

Abstract The functionalization of C(sp 3 )−H bonds streamlines chemical synthesis by allowing the use simple molecules and providing novel synthetic disconnections. Intensive recent efforts in development new reactions based on C−H have led to its wider adoption across a range research areas. This Review discusses strengths weaknesses three main approaches: transition‐metal‐catalyzed activation, 1, n ‐hydrogen atom transfer, carbene/nitrene for directed unactivated bonds. For each strategy, scope, reactivity different bonds, position reacting relative directing group, stereochemical outcomes are illustrated with examples literature. aim this is provide guidance inspire future area.

Language: Английский

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Katalytische Funktionalisierung von C(sp²)‐H‐ und C(sp³)‐H‐Bindungen unter Verwendung von zweizähnigen dirigierenden Gruppen

Angewandte Chemie, Journal Year: 2013, Volume and Issue: 125(45), P. 11942 - 11959

Published: Sept. 17, 2013

Abstract C‐H‐Bindungen sind in organischen Verbindungen allgegenwärtig. Daher erscheint die direkte Funktionalisierung von Substraten durch Aktivierung als eine gute Strategie, weil so Herstellung funktionalisierter Ausgangsstoffe vermieden werden kann. Wichtig ist hierbei der Aspekt Regioselektivität, da organische Moleküle viele enthalten können. Erzielt kann solche Regiokontrolle Verwendung einer dirigierenden Gruppe, den Katalysator unmittelbare Nähe zur umzusetzenden C‐H‐Bindung bringt. Viele funktionelle Gruppen wurden hinsichtlich dirigierende bei Umwandlung getestet. 2005 berichteten Daugulis et al. über Arylierung nicht‐aktivierten C(sp 3 )‐H‐Bindungen mit 8‐Aminochinolin und Picolinamid zweizähnigen Gegenwart Pd(OAc) 2 Katalysator. Basierend auf diesem Befund wurde seitdem Reihe C‐H‐Funktionalisierungen unter Systemen zweizähniger dirigierender entwickelt. In Aufsatz jüngsten Fortschritte Gebiet erörtert.

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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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Cobalt‐Catalyzed, Aminoquinoline‐Directed C(sp²)H Bond Alkenylation by Alkynes

Angewandte Chemie International Edition, Journal Year: 2014, Volume and Issue: 53(38), P. 10209 - 10212

Published: July 24, 2014

A method for cobalt-catalyzed, aminoquinoline- and picolinamide-directed C(sp(2))-H bond alkenylation by alkynes was developed. The shows excellent functional-group tolerance both internal terminal are competent substrates the coupling. reaction employs a Co(OAc)2⋅4 H2O catalyst, Mn(OAc)2 co-catalyst, oxygen (from air) as oxidant.

Language: Английский

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Dehydrierende Kreuzkupplungen von C‐H‐Bindungen: vielseitige Verfahren zur Bildung von C‐C‐Bindungen

Angewandte Chemie, Journal Year: 2013, Volume and Issue: 126(1), P. 76 - 103

Published: Nov. 8, 2013

Abstract In den vergangenen zehn Jahren wurde eine beeindruckende Zahl an Verfahren entwickelt, die selektiven Aufbau von C‐C‐Bindungen über direkte Verknüpfung zwei unterschiedlichen C‐H‐Bindungen unter oxidativen Bedingungen ermöglichen. Diesen Methoden ist gemeinsam, dass reaktiven Zwischenstufen durch Aktivierung der beiden in situ gebildet werden. Diese Strategie Gruppe Li als dehydrierende Kreuzkupplung (CDC, “cross‐dehydrogenative coupling”) eingeführt und eröffnet abfallarme Synthesealternativen zu klassischen Kupplungsverfahren, sich auf Verwendung vorfunktionalisierten Ausgangsstoffen stützen. Dieser Aufsatz hebt Fortschritte dem Gebiet dehydrierenden C ‐C‐Bindungsknüpfungen hervor liefert einen umfassenden Überblick vorhandenen Verfahren.

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(Pentamethylcyclopentadienyl)cobalt(III)‐Catalyzed C–H Bond Functionalization: From Discovery to Unique Reactivity and Selectivity

Advanced Synthesis & Catalysis, Journal Year: 2017, Volume and Issue: 359(8), P. 1245 - 1262

Published: March 16, 2017

Abstract High‐valent (pentamethylcyclopentadienyl)cobalt(III) [Cp*Co(III)] catalysts were found as inexpensive alternatives to (pentamethylcyclopentadienyl)rhodium(III) [Cp*Rh(III)] in the field of C—H bond functionalization, and applied a variety transformations. In this review, after discovery early examples Cp*Co(III)‐catalyzed functionalization are summarized, unique reactivity selectivity Cp*Co(III) differences between cobalt rhodium catalysis intensively discussed. Such assumed be caused by lower electronegativity, hard nature, smaller ionic radius cobalt. magnified image

Language: Английский

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