Recent advances in polyoxometalates acid-catalyzed organic reactions

Chinese Chemical Letters, Journal Year: 2022, Volume and Issue: 34(5), P. 108097 - 108097

Published: Dec. 24, 2022

Language: Английский

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Synthesis of Sulfilimines Enabled by Copper-Catalyzed S-Arylation of Sulfenamides

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(11), P. 6310 - 6318

Published: March 9, 2023

Herein, an unprecedented synthetic route to sulfilimines via a copper-catalyzed Chan–Lam-type coupling of sulfenamides is presented. A key success in this novel transformation the chemoselective S-arylation S(II) form S(IV) sulfilimines, overriding competitive, and more thermodynamically favored, C–N bond formation that does not require change sulfur oxidation state. Computations reveal selectivity arises from selective transmetallation event where bidentate sulfenamide coordination through oxygen atoms favors pathway. The mild environmentally benign catalytic conditions enable broad functional group compatibility, allowing variety diaryl or alkyl aryl be efficiently prepared. Chan–Lam procedure could also tolerate alkenylboronic acids as partners afford alkenyl class scaffolds cannot directly synthesized conventional imination strategies. benzoyl-protecting groups conveniently removed product, which, turn, readily transformed into several S(VI) derivatives.

Language: Английский

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Cu-Mediated Thianthrenation and Phenoxathiination of Arylborons

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(18), P. 10431 - 10440

Published: April 26, 2023

Great success in synthetic chemistry is motivated by the development of novel and reactive linchpins for carbon-carbon carbon-heteroatom bond formation reactions, which has dramatically altered chemists' approach to building molecules. Herein, we report ready synthesis aryl sulfonium salts, a versatile electrophilic linchpin, via Cu-mediated thianthrenation phenoxathiination commercially available arylborons with thianthrene phenoxathiine, providing series salts high efficiency. More importantly, leveraging sequential Ir-catalyzed C-H borylation arylborons, formal arenes also achieved. The undirected normally occurred at less steric hindrance position, thus complementary method comparison thianthrenation. This process capable late-stage functionalization pharmaceuticals, might find wide applications both industry academic sectors.

Language: Английский

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Sulfur-Arylation of Sulfenamides via Chan–Lam Coupling with Boronic Acids: Access to High Oxidation State Sulfur Pharmacophores

Organic Letters, Journal Year: 2023, Volume and Issue: 25(16), P. 2830 - 2834

Published: April 12, 2023

Sulfur-arylation of sulfenamides is reported. This reaction proceeds via a Chan-Lam-type coupling with commercially abundant boronic acids to give sulfilimines. A broad scope was established variety readily accessible aryl and alkyl sulfenamide acid inputs. Synthetic utility functional group compatibility were further demonstrated through the direct late-stage introduction sulfilimines into approved drugs. Derivatization sulfilimine products provided access medicinally relevant sulfoximines sulfondiimines.

Language: Английский

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Synthesis of polysubstituted azepanes by dearomative ring expansion of nitroarenes

Nature Chemistry, Journal Year: 2024, Volume and Issue: 16(5), P. 771 - 779

Published: Jan. 25, 2024

Language: Английский

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Planar Core and Macrocyclic Shell Stabilized Atomically Precise Copper Nanocluster Catalyst for Efficient Hydroboration of C–C Multiple Bond

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(23), P. 16295 - 16305

Published: May 30, 2024

Atomically precise metal nanoclusters (NCs) have become an important class of catalysts due to their catalytic activity, high surface area, and tailored active sites. However, the design development bond-forming reaction based on copper NCs are still in early stages. Herein, we report synthesis atomically nanocluster with a planar core unique shell, [Cu45(TBBT)29(TPP)4(C4H11N)2H14]2+ (Cu45) (TBBT: 4-tert-butylbenzenethiol; TPP: triphenylphosphine), yield via one-pot reduction method. The resulting structurally well-defined Cu45 is highly efficient catalyst for hydroboration alkynes alkenes. Mechanistic studies show that single-electron oxidation situ-formed ate complex enables formation boryl-centered radicals under mild conditions. This work demonstrates promise as C–B heteroatom reactions. compatible wide range alkenes functional groups producing hydroborated products.

Language: Английский

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Photocatalytic Generation of Aminium Radical Cations for C–N Bond Formation

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(20), P. 11712 - 11738

Published: Sept. 11, 2020

Aminium radical cations have been extensively studied as electrophilic aminating species that readily participate in C–N bond forming processes with alkenes and arenes. However, their utility synthesis has limited, generation required unstable, reactive starting materials harsh reaction conditions. Visible-light photoredox catalysis emerged a platform for the mild production of aminium from either unfunctionalized or N-functionalized amines. This Perspective covers recent synthetic methods rely on photocatalytic formation, specifically context alkene hydroamination, arene C–H amination, mesolytic cleavage alkoxyamines.

Language: Английский

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Metal-Free, Redox-Neutral, Site-Selective Access to Heteroarylamine via Direct Radical–Radical Cross-Coupling Powered by Visible Light Photocatalysis

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(39), P. 16805 - 16813

Published: Sept. 8, 2020

Transition-metal-catalyzed C–N bond-forming reactions have emerged as fundamental and powerful tools to construct arylamines, a common structure found in drug agents, natural products, fine chemicals. Reported herein is an alternative access heteroarylamine via radical–radical cross-coupling pathway, powered by visible light catalysis without any aid of external oxidant reductant. Only irradiation photocatalyst, such metal-free does the cascade single-electron transfer event for amines heteroaryl nitriles occur, demonstrated steady-state transient spectroscopic studies, resulting amine radical cation aryl anion situ bond formation. The redox economic nature, high efficiency, site-selectivity range available amines, hydroxylamines, hydrazines with make this protocol promising both academic industrial settings.

Language: Английский

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Utilization of C(sp³)‐Carboxylic Acids and Their Redox‐Active Esters in Decarboxylative Carbon−Carbon Bond Formation

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(15), P. 3693 - 3736

Published: May 11, 2021

Abstract Over the last several years, radical‐mediated decarboxylative cross‐coupling reactions employing alkyl carboxylic acids have emerged as a powerful tool for regiospecific construction of carbon−carbon bonds. Under thermal or photocatalytic conditions, wide variety C( sp 3 )‐carboxylic and their redox‐active esters undergo C−C bond formation with suitable reactant partners, leading to complex chemical scaffolds wide‐ranging applications. This synthetic strategy has advantages over more conventional organometallic reagents, including abundant starting material availability high functional group tolerance associated mild reaction conditions. review article highlights recent developments in functionalization α‐heteroatom‐substituted well challenging unactivated acids, representative examples discussed against backdrop insightful comments on mechanisms. In addition, synthesis natural products, drug molecules, late‐stage modification bioactive molecules this non‐traditional are included. been categorized into three main sections that organized around type being forged: )−C( 2 ), ). Further, separately each section. magnified image

Language: Английский

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An Improved P^III/P^V═O-Catalyzed Reductive C–N Coupling of Nitroaromatics and Boronic Acids by Mechanistic Differentiation of Rate- and Product-Determining Steps

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(14), P. 6786 - 6799

Published: March 16, 2020

Experimental, spectroscopic, and computational studies are reported that provide an evidence-based mechanistic description of intermolecular reductive C–N coupling nitroarenes arylboronic acids catalyzed by a redox-active main-group catalyst (1,2,2,3,4,4-hexamethylphosphetane P-oxide, i.e., 1·[O]). The central observations include the following: (1) catalytic reduction 1·[O] to PIII phosphetane 1 is kinetically fast under conditions catalysis; (2) represents resting state as observed 31P NMR spectroscopy; (3) there no long-lived nitroarene partial-reduction intermediates observable 15N (4) reaction sensitive solvent dielectric, performing best in moderately polar solvents (viz. cyclopentylmethyl ether); (5) largely insensitive with respect common hydrosilane reductants. On basis foregoing studies, new modified described expand scope for mild temperatures (T ≥ 60 °C), low loadings (≥2 mol%), innocuous terminal reductants (polymethylhydrosiloxane). DFT calculations define two-stage deoxygenation sequence coupling. initial involves rate-determining step consists (3+1) cheletropic addition between substrate 1; energy decomposition techniques highlight biphilic character this step. Although invisible, second stage implicated critical product-forming event, which postulated oxazaphosphirane intermediate diverted from arylnitrene dissociation toward heterolytic ring opening acid; resulting dipolar evolves antiperiplanar 1,2-migration organoboron residue nitrogen, displacement formation target product upon situ hydrolysis. method thus constitutes mechanistically well-defined operationally robust complement current workhorse transition-metal-based methods

Language: Английский

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