Electrophilic Sulfur Reagent Design Enables Directed syn-Carbosulfenylation of Unactivated Alkenes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(16), С. 7189 - 7197

Опубликована: Апрель 18, 2022

A multi-component approach to structurally complex organosulfur products is described via the nickel-catalyzed 1,2-carbosulfenylation of unactivated alkenes with organoboron nucleophiles and tailored electrophiles. The key development this transformation identification a modular N-alkyl-N-(arylsulfenyl)arenesulfonamide family sulfur Tuning electronic steric properties leaving group in these reagents controls pathway selectivity, favoring three-component coupling suppressing side reactions, as examined computational studies. unique syn-stereoselectivity differs from traditional electrophilic sulfenyl transfer processes involving thiiranium ion intermediate arises directed arylnickel(I) migratory insertion mechanism, elucidated through reaction kinetics control experiments. Reactivity regioselectivity are facilitated by collection monodentate, weakly coordinating native directing groups, including sulfonamides, alcohols, amines, amides, azaheterocycles.

Язык: Английский

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Structurally Diverse Bench‐Stable Nickel(0) Pre‐Catalysts: A Practical Toolkit for In Situ Ligation Protocols**

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(9)

Опубликована: Дек. 16, 2022

A flurry of recent research has centered on harnessing the power nickel catalysis in organic synthesis. These efforts have been bolstered by contemporaneous development well-defined (pre)catalysts with diverse structure and reactivity. In this report, we present ten different bench-stable, 18-electron, formally zero-valent nickel-olefin complexes that are competent pre-catalysts various reactions. Our investigation includes preparations novel, bench-stable Ni(COD)(L) (COD=1,5-cyclooctadiene), which L=quinone, cyclopentadienone, thiophene-S-oxide, fulvene. Characterization NMR, IR, single-crystal X-ray diffraction, cyclic voltammetry, thermogravimetric analysis, natural bond orbital analysis sheds light structure, bonding, properties these complexes. Applications an assortment nickel-catalyzed reactions underscore complementary nature within toolkit.

Язык: Английский

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Intermolecular Redox-Neutral Carboamination of C–C Multiple Bonds Initiated by Transition-Metal-Catalyzed C–H Activation

ACS Catalysis, Год журнала: 2022, Номер 12(23), С. 14754 - 14772

Опубликована: Ноя. 18, 2022

Carboamination of readily available feedstock-like alkenes, alkynes, and allenes has proven to be an efficient powerful tool for the synthesis diverse valuable amine derivatives relevance medicinal chemistry, biochemistry, material science. Among these developed carboamination methodologies, direct use C–H activation strategy leverage process is particularly attractive due ubiquity such bonds in organic molecules. In this review, we provide overview development intermolecular across C–C π-bonds initiated by a redox-neutral nonannulative manner, with emphasis on synthetic mechanistic aspects. principle, review summarized reactions key feature involving initial metalation followed migratory insertion into terminated electrophilic amination quenching, thus, it ordered sources C- N-based functionalities further divided π-compounds.

Язык: Английский

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Catalytic intramolecular aminoarylation of unactivated alkenes with aryl sulfonamides

Chemical Science, Год журнала: 2022, Номер 13(23), С. 6942 - 6949

Опубликована: Янв. 1, 2022

Arylethylamines are abundant motifs in myriad natural products and pharmaceuticals, so efficient methods to synthesize them valuable drug discovery. In this work, we disclose an intramolecular alkene aminoarylation cascade that exploits the electrophilicity of a nitrogen-centered radical form C-N bond, then repurposes nitrogen atom's sulfonyl activating group as traceless linker subsequent C-C bond. This photoredox catalysis protocol enables preparation densely substituted arylethylamines from commercially aryl sulfonamides unactivated alkenes under mild conditions. Reaction optimization, scope, mechanism, synthetic applications discussed.

Язык: Английский

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Nickel-Catalyzed 1,1-Aminoborylation of Unactivated Terminal Alkenes

ACS Catalysis, Год журнала: 2023, Номер 13(8), С. 5538 - 5543

Опубликована: Апрель 10, 2023

Herein, we disclose a Ni-catalyzed 1,1-difunctionalization of unactivated terminal alkenes that enables the incorporation two different heteroatom motifs across an olefin backbone, thus streamlining access to α-aminoboronic acid derivatives from simple precursors. The method is characterized by its simplicity and generality wide number coupling counterparts.

Язык: Английский

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Benchtop Nickel Catalysis Invigorated by Electron-Deficient Diene Ligands

Accounts of Chemical Research, Год журнала: 2024, Номер 57(3), С. 312 - 326

Опубликована: Янв. 18, 2024

ConspectusDue to the rarity of precious metals like palladium, nickel catalysis is becoming an increasingly important player in organic synthesis, especially for formation bonds with sp3-hybridized carbon centers. Traditionally, catalytic processes involving active Ni(0) species have relied on Ni(COD)2 or situ reduction Ni(II) salts. However, air- and temperature-sensitive material that requires use inert-atmosphere glovebox, protocols salts using metallic organometallic reductants add additional complications reaction development.This Account chronicles development air-stable precursors as replacements reduction. Based Schrauzer's seminal discovery Ni(COD)(DQ) zerovalent organonickel complex, our research laboratories at Scripps Research Bristol Myers Squibb developed a class precatalysts based Ni(COD)(EDD) (EDD = electron-deficient diene) framework, relying steric electronic properties supporting diene render metal center stable air, moisture, even silica gel but reactive ligand substitution redox changes.The complexes can be accessed through exchange Ni(COD)2, Ni(acac)2 DIBAL-H, electrochemically via cathodic followed by addition EDD one pot. As toolkit, demonstrate reactivity equivalent enhanced compared catalyzing C–C C–N cross-couplings, Miyaura borylations, C–H activations, other transformations. Since initial report Ni(COD)(DQ), its C(sp2)–CN activation, metallophotoredox, electric field-induced cross-coupling also been demonstrated.By incorporating precatalyst toolkit into campaigns, able perform C(sp3)–S(alkyl) couplings metallonitrenoid carboamination, both which represent challenging transformations were inaccessible traditional phosphine, nitrogen, olefin ligands. Computational experimental studies how quinone ligands are hemilabile, adopting η1(O)-bound geometries relieve strain stabilize transition states intermediates; redox-active, transiently oxidize center; electron-withdrawing -donating, depending oxidation state coordination geometry. These show enable key steps beyond imparting air-stability.Since documenting activity many observed unique this precatalyst. was found offer superior cross coupling form N,N-diaryl sulfonamides preparation biaryls from aryl halides benzene Ni-mediated, base-assisted homolytic aromatic substitution.

Язык: Английский

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Synthesis of Unprotected β‐Arylethylamines by Iron(II)‐Catalyzed 1,2‐Aminoarylation of Alkenes in Hexafluoroisopropanol

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(9)

Опубликована: Дек. 21, 2022

β-Arylethylamines are prevalent structural motifs in molecules exhibiting biological activity. Here we report a sequential one-pot protocol for the 1,2-aminoarylation of alkenes with hydroxylammonium triflate salts and (hetero)arenes. Unlike existing methods, this reaction provides direct entry to unprotected β-arylethylamines remarkable functional group tolerance, allowing key drug-oriented groups be installed two-step process. The use hexafluoroisopropanol as solvent combination an iron(II) catalyst proved essential reaching high-value nitrogen-containing molecules.

Язык: Английский

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Modular Synthesis of Unnatural Peptides via Rh(III)-Catalyzed Diastereoselective Three-Component Carboamidation Reaction

Journal of the American Chemical Society, Год журнала: 2022, Номер 145(2), С. 1129 - 1135

Опубликована: Дек. 28, 2022

Herein we report a modular peptide ligation methodology that couples dioxazolones, arylboronic acids, and acrylamides to construct amide bonds in diastereoselective manner under mild conditions, facilitated by Rh(III) catalysis. By converting the C-terminus of one into dioxazolone N-terminus second an acrylamide, two pieces can be bridged acid unnatural phenylalanine, tyrosine, tryptophan residues at junction point with diastereoselectivity for their corresponding d-stereocenters. The reaction exhibits excellent functional group tolerance large substrate scope is compatible wide array protected amino are utilized Fmoc solid phase synthesis. applied synthesis six diastereomeric proteasome inhibitor analogs, as well 10-mer oligopeptides 21-mer polypeptide phenylalanine residue center.

Язык: Английский

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Enantioselective Ni‐Catalyzed Three‐Component Dicarbofunctionalization of Alkenes

ChemCatChem, Год журнала: 2023, Номер 15(18)

Опубликована: Авг. 3, 2023

Abstract Asymmetric multicomponent reactions are considered as efficient protocols for constructing complex chiral molecules because of their step‐ and atom‐economy. Nickel‐catalyzed asymmetric three‐component dicarbofunctionalization alkenes has been well developed in recent years, which is used the area total synthesis natural products late‐stage modification drugs rapid incorporation sp 3 ‐enriched carbon centers. In this concept, significant breakthroughs field summarized, together with related mechanisms. Moreover, remaining challenges potential opportunities also highlighted.

Язык: Английский

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Alkene 1,1-difunctionalizations via organometallic-radical relay

Nature Catalysis, Год журнала: 2023, Номер 6(11), С. 1030 - 1041

Опубликована: Сен. 28, 2023

Язык: Английский

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