The merger of transition metal and photocatalysis

Nature Reviews Chemistry, Journal Year: 2017, Volume and Issue: 1(7)

Published: July 5, 2017

Language: Английский

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Merging Visible Light Photoredox and Gold Catalysis

Accounts of Chemical Research, Journal Year: 2016, Volume and Issue: 49(10), P. 2261 - 2272

Published: Sept. 9, 2016

ConspectusSince the beginning of this century, π-Lewis acidic gold complexes have become catalysts choice for a wide range organic reactions, especially those involving nucleophilic addition to carbon–carbon multiple bonds. For most part, however, catalyst does not change oxidation state during course these processes and two-electron redox cycles kind implicated in cross-coupling chemistry are easily accessible. In order address limitation expand scope catalysis beyond conventional hydrofunctionalization, extensive efforts been made develop new oxidative reactions using strong external oxidants capable overcoming high potential AuI/AuIII couple. However, typically require superstoichiometric amounts oxidant proceed under relatively harsh conditions. Moreover, date, gold-catalyzed coupling remained somewhat limited because, many systems, desired favorably compete with homodimerization or hydrofunctionalization.In 2013, we disclosed concept that, rather than oxidants, employs aryl radicals that act as both partner overall redox-neutral transformations. this, developed dual catalytic system combining homogeneous emerging field visible light photoredox catalysis. Using aryldiazonium salts, which known sources upon activation reducing photocatalysts, could achieve intramolecular oxy- aminoarylations alkenes irradiating reaction mixtures light. Further studies on transformation, onto gold-activated alkene is followed by C(sp3)–C(sp2) bond formation, expanded process intermolecular, three-component oxyarylation, while inexpensive dyes user-friendly diaryliodonium salts be employed alternative photocatalysts radical sources, respectively.The gold/photoredox was quickly realized several research groups diverse π-systems even P–H C(sp)–H functionalization developed. ambient conditions simple setup household sunlight, key advantage results from simultaneous gold(I) coordination partner, levels selectivity cross-coupled products over homodimers. Furthermore, when catalytically active prior employed, background can suppressed. Notably, feature has allowed successful use allenes alkynes, hydrofunctionalization pathways highly favored, opening door transformations common substrate classes Account, provide an overview highlight greatly enable efficient construction complex molecules. recent light-promoted synthesis novel gold(III) suggest yet find further applications coupling.

Language: Английский

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The activation strain model and molecular orbital theory

Wiley Interdisciplinary Reviews Computational Molecular Science, Journal Year: 2015, Volume and Issue: 5(4), P. 324 - 343

Published: May 18, 2015

The activation strain model is a powerful tool for understanding reactivity, or inertness, of molecular species. This done by relating the relative energy complex along reaction profile to structural rigidity reactants and strength their mutual interactions: Δ E ( ζ ) = + int ). We provide detailed discussion model, elaborate on its strong connection with orbital theory. Using these approaches, causal relationship revealed between properties e.g., barriers plausible mechanisms. methodology may reveal intriguing parallels completely different types chemical transformations. Thus, constitutes unifying framework that furthers development cross‐disciplinary concepts throughout various fields chemistry. illustrate in action selected examples from literature. These demonstrate how applied research questions, results are interpreted, insights into one phenomenon can lead an improved another, seemingly process. WIREs Comput Mol Sci 2015, 5:324–343. doi: 10.1002/wcms.1221 article categorized under: Structure Mechanism > Molecular Structures

Language: Английский

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Reactivity of Gold Complexes towards Elementary Organometallic Reactions

Angewandte Chemie International Edition, Journal Year: 2015, Volume and Issue: 54(50), P. 15022 - 15045

Published: Nov. 13, 2015

Abstract For a while, the reactivity of gold complexes was largely dominated by their Lewis acid behavior. In contrast to other transition metals, elementary steps organometallic chemistry—oxidative addition, reductive elimination, transmetallation, migratory insertion—have scarcely been studied in case or even remained unprecedented until recently. However, within last few years, ability undergo these fundamental reactions has unambiguously demonstrated, and shown extend well beyond π‐activation. this Review, main achievements described area are presented historical context. Particular emphasis is set on mechanistic studies structure determination key intermediates. The electronic structural parameters delineating discussed, as remaining challenges.

Language: Английский

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Light in Gold Catalysis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(14), P. 8868 - 8925

Published: Jan. 25, 2021

Within the wide family of gold-catalyzed reactions, gold photocatalysis intrinsically features unique elementary steps. When catalysis meets photocatalysis, a valence change center can easily be achieved via electron transfer and radical addition, avoiding use stoichiometric sacrificial external oxidants. The excellent compatibility radicals with catalysts opens door to series important organic transformations, including redox-neutral C–C C–X coupling, C–H activation, formal radical–radical cross-coupling. complexes nicely complements existing photoredox strategies also new avenue for chemistry. This review covers transformations both mononuclear gold(I) (with without photosensitizer) dinuclear photocatalysts. Various fascinating methodologies, their value chemists, current mechanistic understanding are discussed. most recent examples demonstrate feasibility both, participate in excited state energy (EnT), rather than transfer. rare applications gold(III) photocatalysts, homogeneous heterogeneous, summarized.

Language: Английский

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Stable gold(III) catalysts by oxidative addition of a carbon–carbon bond

Nature, Journal Year: 2015, Volume and Issue: 517(7535), P. 449 - 454

Published: Jan. 1, 2015

Language: Английский

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Rational development of catalytic Au(I)/Au(III) arylation involving mild oxidative addition of aryl halides

Nature Communications, Journal Year: 2017, Volume and Issue: 8(1)

Published: Sept. 12, 2017

The reluctance of gold to achieve oxidative addition reaction is considered as an intrinsic limitation for the development gold-catalyzed cross-coupling reactions with simple and ubiquitous aryl halide electrophiles. Here, we report rational construction a Au(I)/Au(III) catalytic cycle involving sequence Csp2-X addition, Csp2-H auration reductive elimination, allowing direct arylation arenes halides. Key this discovery use Me-Dalphos, ancillary (P,N) ligand, that allows bottleneck iodides bromides readily proceed under mild conditions. hemilabile character amino group plays crucial role in transformation, substantiated by density functional theory calculations.Catalysis cycles are notoriously hampered Au(I) towards addition. authors show bidentate ligand promotes halides formation biaryl coupling products.

Language: Английский

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Nonclassical Applications of closo-Carborane Anions: From Main Group Chemistry and Catalysis to Energy Storage

Chemical Reviews, Journal Year: 2019, Volume and Issue: 119(14), P. 8262 - 8290

Published: Feb. 1, 2019

Classically closo-carborane anions, particularly [HCB11H11]- and [HCB9H9]-, their derivatives have primarily been used as weakly coordinating anions to isolate reactive intermediates, platforms for stoichiometric catalytic functionalization, counteranions simple Lewis acid catalysis, components of materials like liquid crystals. The aim this article is educate the reader on contemporary nonclassical applications these anions. Specifically, review will cover new directions in main group catalysis utilized achieve some most challenging reactions such C-F, C-H, C-C functionalizations that are difficult or impossible realize with transition metals. In addition, utilization clusters dianionic C σ-bound ligands coordination chemistry, ligand substituents chemistry advanced catalyst design, covalently bound spectator stabilize radicals. Furthermore, solution-based solid-state electrolytes Li, Na, Mg batteries be discussed.

Language: Английский

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Mechanistic Analysis of Metallaphotoredox C–N Coupling: Photocatalysis Initiates and Perpetuates Ni(I)/Ni(III) Coupling Activity

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(37), P. 15830 - 15841

Published: Aug. 4, 2020

The combined use of reaction kinetic analysis, ultrafast spectroscopy, and stoichiometric organometallic studies has enabled the elucidation mechanistic underpinnings to a photocatalytic C-N cross-coupling reaction. Steady-state spectroscopic techniques were used track excited-state evolution employed iridium photocatalyst, determine resting states both nickel catalysts, uncover photochemical mechanism for reductive activation cocatalyst. Stoichiometric along with comprehensive study reaction, including rate-driving force unveiled crucial role photocatalysis in initiating sustaining Ni(I)/Ni(III) mechanism. insights gleaned from this further discovery new photocatalyst providing >30-fold rate increase.

Language: Английский

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Recent Advances in Gold(III) Chemistry: Structure, Bonding, Reactivity, and Role in Homogeneous Catalysis

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(14), P. 8364 - 8451

Published: Sept. 23, 2020

Over the past decade organometallic chemistry of gold(III) has seen remarkable advances. This includes synthesis first examples several compound classes that have long been hypothesized as being part catalytic cycles, such alkene, alkyne, CO and hydride complexes, important catalysis-relevant reaction steps at last demonstrated for gold, like migratory insertion β-H elimination reactions. Also, pathways were already known, example generation intermediates by oxidative addition their reductive elimination, are much better understood. A deeper understanding fundamental reactivity revealed unexpected mechanistic avenues, which can open when barriers reactions other metals would be regarded "standard" too high. review summarizes evaluates these developments, together with applications in catalysis, emphasis on insight gained investigations.

Language: Английский

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