Enantioselective C−H Functionalization Reactions under Gold Catalysis

Chemistry - A European Journal, Год журнала: 2022, Номер 28(20)

Опубликована: Янв. 11, 2022

Abstract Transition metal‐catalyzed enantioselective functionalization of ubiquitous C−H bonds has proven to be promising field as it offers the construction chiral molecular complexity in a step‐ and atom‐economical manner. In recent years, gold emerged an attractive contender for catalyzing such reactions. The unique reactivities selectivities offered by catalysts have been exploited access numerous asymmetric transformations based on gold‐catalyzed processes. Herein, this review critically highlights major advances discoveries made under catalysis which is accompanied mechanistic insights at appropriate places.

Язык: Английский

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Metal-Catalyzed Enantioconvergent Transformations

Chemical Reviews, Год журнала: 2023, Номер 123(20), С. 11817 - 11893

Опубликована: Окт. 4, 2023

Enantioconvergent catalysis has expanded asymmetric synthesis to new methodologies able convert racemic compounds into a single enantiomer. This review covers recent advances in transition-metal-catalyzed transformations, such as radical-based cross-coupling of alkyl electrophiles with nucleophiles or alkylmetals and reductive two mainly under Ni/bis(oxazoline) catalysis. C–H functionalization can be performed an enantioconvergent manner. Hydroalkylation alkenes, allenes, acetylenes is alternative reactions. Hydrogen autotransfer been applied amination alcohols C–C bond forming reactions (Guerbet reaction). Other metal-catalyzed involve addition allylic systems carbonyl compounds, propargylation phenols, 3-bromooxindoles, allenylation allenolates propargyl bromides, hydroxylation 1,3-dicarbonyl compounds.

Язык: Английский

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Cobalt-catalyzed enantioselective C–H/N–H annulation of aryl sulfonamides with allenes or alkynes: facile access to C–N axially chiral sultams

Chemical Science, Год журнала: 2023, Номер 14(26), С. 7291 - 7303

Опубликована: Янв. 1, 2023

Herein we report a cobalt-catalyzed enantioselective C-H/N-H annulation of aryl sulfonamides with allenes and alkynes, using either chemical or electrochemical oxidation. By O2 as the oxidant, proceeds efficiently low catalyst/ligand loading 5 mol% tolerates wide range allenes, including 2,3-butadienoate, allenylphosphonate, phenylallene, resulting in C-N axially chiral sultams high enantio-, regio-, position selectivities. The alkynes also exhibits excellent enantiocontrol (up to >99% ee) variety functional sulfonamides, internal terminal alkynes. Furthermore, oxidative is achieved simple undivided cell, demonstrating versatility robustness cobalt/Salox system. gram-scale synthesis asymmetric catalysis further highlight practical utility this method.

Язык: Английский

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Rhodium-catalyzed enantioselective and diastereodivergent access to diaxially chiral heterocycles

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Авг. 3, 2023

N-N axially chiral biaryls represent a rarely explored class of atropisomers. Reported herein is construction diverse classes diaxially containing and C-N/C-C diaxes in distal positions excellent enantioselectivity diastereoselectivity. The axis the products provides handle toward solvent-driven diastereodivergence, as has been realized coupling large scope benzamides sterically hindered alkynes, affording complementary diastereodivergence elucidated by computational studies which revealed that hexafluoroisopropanol (HFIP) solvent molecule participated an unusual manner well ligand switched sequence two competing elementary steps, resulting switch stereoselectivity alkyne insertion inversion configuration C-C axis. Further cleavage N-directing group diaxial transforms to enantiodivergence.

Язык: Английский

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Sulfoxide-Directed or 3d-Metal Catalyzed C–H Activation and Hypervalent Iodines as Tools for Atroposelective Synthesis

Accounts of Chemical Research, Год журнала: 2023, Номер 56(3), С. 189 - 202

Опубликована: Янв. 27, 2023

ConspectusThe expanding applications of atropisomeric compounds combined with the growing diversity such chiral molecules translate into an urgent need for innovative synthetic strategies allowing their rapid, efficient, and sustainable synthesis. Recently, C-H activation approach has provided new opportunities synthesizing axially compounds. The two complementary approaches implementation methodology toward synthesis imply either ortho-functionalization preexisting prochiral or atropo-unstable biaryl substrates direct arylation sterically encumbered aromatics. first required preinstallation a directing group on precursor, which drastically limits thus generated products. To tackle this important limitation, we have envisioned using sulfoxide as both auxiliary. Indeed, in addition to efficiently coordinating Pd-catalyst induction, moiety can be easily removed, via sulfoxide/lithium exchange, after step, guaranteeing almost unlimited postdiversification efficiency generality concept could illustrated by developing atropo-diastereoselective oxidative Heck reaction, acetoxylation, iodination, well arylation. Besides, utility was demonstrated designing expedient steganone precursor. This unique transformation also allowed us build up unprecedented triaryl scaffolds perfectly controlled axes, original skeletons ligand design. While considering atroposelective arylations, clear antagonism between harsh reaction conditions frequently coupling hindered atropo-stability product, resulted scarcity transformations. solve fundamental challenge, focused application low-valent cobalt catalyst, prompted catalyze indoles at C2 position under extremely mild (room temperature). Accordingly, C2-arylation achieved carbene delivering uncommon atropoisomerically pure excellent yields enantioselectivities. Detailed experimental theoretical mechanistic studies shed light mechanism transformation, providing strong evidence regarding origin enantioselectivity. Finally, steric hindrance guarantee molecule couple partners is limitation not only development but C-N Despite long history incredible advances Ullmann-Goldberg Buchwald-Hartwig couplings, versions transformations remained until recently. Our idea challenging issue consisted hypervalent iodines highly reactive partners, desired N-arylations occur room temperature. hypothesis validated reporting Cu-catalyzed N-arylation, λ3-iodanes partners. Subsequently, enantioselective version N-arylation successfully established Cu-complex bearing BOX ligand. In conclusion, report herein tailored-made solutions provide construct molecules, including biaryls molecules.

Язык: Английский

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Recent advances in Rh(i)-catalyzed enantioselective C–H functionalization

Chemical Society Reviews, Год журнала: 2024, Номер 53(7), С. 3457 - 3484

Опубликована: Янв. 1, 2024

Chiral carbon-carbon (C-C) and carbon-heteroatom (C-X) bonds are pervasive very essential in natural products, bioactive molecules, functional materials, their catalytic construction has emerged as one of the hottest research fields synthetic organic chemistry. The last decade witnessed vigorous progress Rh(I)-catalyzed asymmetric C-H functionalization a complement to Rh(II) Rh(III) catalysis. This review aims provide most comprehensive up-to-date summary covering recent advances activation for functionalization. In addition development diverse reactions, chiral ligand design mechanistic investigation (inner-sphere mechanism, outer-sphere 1,4-Rh migration) will also be highlighted.

Язык: Английский

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Transient Directing Groups in Metal−Organic Cooperative Catalysis

Chemistry - A European Journal, Год журнала: 2021, Номер 27(56), С. 13899 - 13952

Опубликована: Июль 19, 2021

The direct functionalization of C-H bonds is among the most fundamental chemical transformations in organic synthesis. However, when innate reactivity substrate cannot be utilized for a given single bond, this selective bond mostly relies on use directing groups that allow bringing catalyst close proximity to activated and these need installed before cleaved after transformation, which involves two additional undesired synthetic operations. These steps dramatically reduce overall impact attractiveness techniques since classical approaches based pre-functionalization are sometimes still more straightforward appealing. During past decade, different approach involving both situ installation removal group, can then often used catalytic manner, has emerged: transient group strategy. In addition its innovative character, strategy brought an unprecedented level usefulness enabled development remarkably efficient processes introduction functional onto aromatic aliphatic substrates. unlocked by will comprehensively overviewed review article.

Язык: Английский

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Asymmetric Construction of an Aryl‐Alkene Axis by Palladium‐Catalyzed Suzuki–Miyaura Coupling Reaction

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(45)

Опубликована: Сен. 16, 2022

The application of Suzuki-Miyaura coupling reaction to forge the atropisomeric biaryls has seen remarkable progress but exploration this chemistry directly chiral C(aryl)-C(alkene) axis is underdeveloped. replacement arene substrates by alkenes intensifies challenges in terms reactivity, configurational atropostability product and selectivity control. By meticulous ligand design fine-tuning parameters, we identified a highly active 3,3'-triphenylsilyl-substituted phosphite realize arene-alkene hindered aryl halides vinyl boronates under very mild conditions. axially acyclic aryl-alkenes were generated commendable efficiency, enantioselectivity E/Z selectivity.

Язык: Английский

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Enantioselective C−H Bond Functionalization Involving Arene Ruthenium(II) Catalysis

Chemistry - A European Journal, Год журнала: 2022, Номер 29(7)

Опубликована: Окт. 27, 2022

The p-Cymene ruthenium(II) complex is one of the most widely used catalysts in C-H activation. However, enantioselective activation promoted by arene complexes has not been realized until recently. revealed strategies include intramolecular nitrene insertion, use chiral transient directing groups, carboxylic acid, relay catalysis, and ligands. In this minireview, these advances are summarized discussed hope spurring further developments.

Язык: Английский

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In Situ Monitoring of Palladium-Catalyzed Chemical Reactions by Nanogap-Enhanced Raman Scattering using Single Pd Cube Dimers

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(11), С. 5003 - 5009

Опубликована: Март 14, 2022

The central dilemma in label-free situ surface-enhanced Raman scattering (SERS) for monitoring of heterogeneously catalyzed reactions is the need plasmonically active nanostructures signal enhancement. Here, we show that assembly catalytically transition-metal nanoparticles into dimers boosts their intrinsically insufficient plasmonic activity at monomer level by several orders magnitude, thereby enabling SERS various important single-dimer level. Specifically, demonstrate Pd nanocubes (NCs), which alone are not sufficiently as monomers, can act a monometallic yet bifunctional platform with both catalytic and satisfactory via controlled single an ∼1 nm gap. Computer simulations reveal highest enhancement factors (EFs) occur corners gap, has implications SERS-based detection conversions: it sufficient molecules to come contact "hot spot corners", required they diffuse deeply For widely employed Pd-catalyzed Suzuki–Miyaura cross-coupling reaction, such NC be kinetic monitoring, using whole series aryl halides educts. Our generic approach based on easily extended other nanostructures.

Язык: Английский

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