Journal ArticleDOI
Copper-Catalyzed Aerobic Oxidative C ? H Functionalizations: Trends and Mechanistic Insights
TLDR
This work has reported several recently reported Cu-catalyzed C-H oxidation reactions that feature substrates that are electron-deficient or appear unlikely to undergo single-electron transfer to copper(II), and evidence has been obtained for the involvement of organocopper(III) intermediates in the reaction mechanism.Abstract:
The selective oxidation of C-H bonds and the use of O(2) as a stoichiometric oxidant represent two prominent challenges in organic chemistry. Copper(II) is a versatile oxidant, capable of promoting a wide range of oxidative coupling reactions initiated by single-electron transfer (SET) from electron-rich organic molecules. Many of these reactions can be rendered catalytic in Cu by employing molecular oxygen as a stoichiometric oxidant to regenerate the active copper(II) catalyst. Meanwhile, numerous other recently reported Cu-catalyzed C-H oxidation reactions feature substrates that are electron-deficient or appear unlikely to undergo single-electron transfer to copper(II). In some of these cases, evidence has been obtained for the involvement of organocopper(III) intermediates in the reaction mechanism. Organometallic C-H oxidation reactions of this type represent important new opportunities for the field of Cu-catalyzed aerobic oxidations.read more
Citations
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Journal ArticleDOI
Mechanistic Study of a Switch in the Regioselectivity of Hydroheteroarylation of Styrene Catalyzed by Bimetallic Ni–Al through C ? H Activation
Wen-Ching Chen,Ying‐Chieh Lai,Wei-Chun Shih,Ming‐Shiuan Yu,Glenn P. A. Yap,Tiow-Gan Ong,Tiow-Gan Ong +6 more
TL;DR: The mechanism of this process is delineated, providing a rationale for an observed switch in regioselectivity in the presence of the Lewis acid, AlMe3, and gives insights for the rational development of catalysts that exhibit required linear/branched selectivity.
Journal ArticleDOI
Co-Catalyzed Direct Addition of Allylic C(sp3)-H Bonds to Ketones.
TL;DR: By using Co(acac)2/Xantphos with AlMe3, the C(sp3)-H bonds of allylarene derivatives were cleaved for reaction with various ketones, affording the homoallylic alcohols in moderate to good yields.
Journal ArticleDOI
Computational Studies on the Mechanism of the Copper-Catalyzed sp3 -CH Cross-Dehydrogenative Coupling Reaction.
TL;DR: The computational results support an SET mechanism, but also uncover an alternative mechanism in which O2 is directly involved in a hydrogen-abstracting step.
Journal ArticleDOI
Synthesis of Pyrrole-2-carbaldehyde Derivatives by Oxidative Annulation and Direct Csp3-H to C═O Oxidation.
TL;DR: Preliminary mechanistic investigations indicate that the aldehyde oxygen atom originates from oxygen, and the developed scalable approach provides a distinct advantage over traditional oxidative functionalization of C-H moieties, avoiding the use of stoichiometric quantities of hazardous oxidants.
Journal ArticleDOI
Cu(OTf)2-catalyzed selective arene C-H bond hydroxylation and nitration with KNO2 as an ambident O- and N-nucleophile via a Cu(II)-Cu(III)-Cu(I) mechanism.
TL;DR: Cu(OTf)2-catalyzed selective arene C-H bond hydroxylation and nitration reactions of azacalix[1]arene[3]pyridines were achieved using KNO2 as an ambident O- and N-nucleophile under very mild aerobic conditions to yield functionalized azacAlixaromatics.
References
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Journal ArticleDOI
Palladium-Catalyzed Ligand-Directed C−H Functionalization Reactions
TL;DR: This is the first comprehensive review encompassing the large body of work in this field over the past 5 years, and will focus specifically on ligand-directed C–H functionalization reactions catalyzed by palladium.
Journal ArticleDOI
Palladium(II)-catalyzed C-H activation/C-C cross-coupling reactions: versatility and practicality.
TL;DR: A review of palladium-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle can be found in this paper.
Journal ArticleDOI
Catalytic dehydrogenative cross-coupling: forming carbon-carbon bonds by oxidizing two carbon-hydrogen bonds
Charles S. Yeung,Vy M. Dong +1 more
Journal ArticleDOI
Multicopper Oxidases and Oxygenases
TL;DR: Copper sites have historically been divided into three classes based on their spectroscopic features, which reflect the geometric and electronic structure of the active site: type 1 or blue copper, type 2 (T2) or normal copper, and type 3 (T3) or coupled binuclear copper centers.
Journal ArticleDOI
Rhodium-Catalyzed C-C Bond Formation via Heteroatom-Directed C-H Bond Activation
TL;DR: This review focuses on Rh-catalyzed methods for C-H bond functionalization, which have seen widespread success over the course of the last decade and are discussed in detail in the accompanying articles in this special issue of Chemical Reviews.
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