Regiodivergent Ring-Expansion of Oxindoles to Quinolinones

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(7), С. 4301 - 4308

Опубликована: Фев. 9, 2024

The development of divergent methods to expedite structure–activity relationship studies is crucial streamline discovery processes. We developed a rare example regiodivergent ring expansion access two regioisomers from common starting material. To enable this regiodivergence, we identified distinct reaction conditions for transforming oxindoles into quinolinone isomers. presented proved be compatible with variety functional groups, which enabled the late-stage diversification bioactive as well facilitated synthesis drugs and their derivatives.

Язык: Английский

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Cooperative Photoredox and N‐Heterocyclic Carbene Catalyzed Fluoroaroylation for the Synthesis of α‐Trifluoromethyl‐Substituted Ketones

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(48)

Опубликована: Окт. 9, 2023

α-Trifluoromethylated ketones have attracted significant attention as valuable building blocks in organic synthesis. Such compounds are generally accessed through trifluoromethylation of ketones. Here we report an alternative disconnection approach for the construction α-CF3 carbonyl by using aroyl fluorides bifunctional reagents fluoroaroylation gem-difluoroalkenes cooperative photoredox and N-heterocyclic carbene (NHC) catalysis. This strategy bypasses use expensive or sensitive and/or requirement ketone pre-functionalization, thus enabling efficient general synthetic method to access -substituted A wide variety bearing a diverse set functional groups eligible substrates. Notably, developed methodology also provides rapid mono- difluoroalkyl Mechanistic studies reveal that merging catalysis with NHC is essential reaction.

Язык: Английский

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trans-Ge/B 1,1-Hydroboration of Alkynylgermanes with 9-BBN

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Янв. 23, 2025

A 1,1-hydroboration of alkynylgermanes with unique trans-Ge/B stereochemistry under transition-metal-free conditions is reported. Mechanistic studies suggest that a pathway involving α-boration followed by stepwise 1,2-Ge/H shift on the intermediate structurally lies between an alkyne-Ge+ π complex and typical vinyl cation. The resulting Ge/B bimetallic modules, along Ge*/Ge/B trimetallic variant, can be conveniently transformed into trisubstituted olefins through iterative divergent cross-coupling. This work demonstrates incorporating metalloids classical organic reactions may offer unconventional chemical selectivity efficient synthetic applications.

Язык: Английский

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Double strain-release enables formal C–O/C–F and C–N/C–F ring-opening metathesis

Chemical Science, Год журнала: 2024, Номер 15(34), С. 13800 - 13806

Опубликована: Янв. 1, 2024

Metathesis reactions have been established as a powerful tool in organic synthesis. While great advances were achieved double-bond metathesis, like olefin metathesis and carbonyl single-bond has received less attention the past decade. Herein, we describe first C(sp

Язык: Английский

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Borane-Catalyzed C–F Bond Functionalization of gem-Difluorocyclopropenes Enables the Synthesis of Orphaned Cyclopropanes

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(31), С. 17389 - 17397

Опубликована: Июль 26, 2023

Herein, we disclose an approach to synthesize tert-alkyl cyclopropanes by leveraging C-F bond functionalization of gem-difluorocyclopropenes using tris(pentafluorophenyl)borane catalysis. The reaction proceeds through the intermediacy a fluorocyclopropenium ion, which was confirmed isolation [Ph2(C6D5)C3]+[(C6F5)3BF]-. We found that silylketene acetal nucleophiles were optimal partners with ion intermediates yielding fully substituted cyclopropenes functionalized two α-tert-alkyl centers (63-93% yield). regioselectivity addition cyclopropenium ions is controlled their steric and electronic properties enables access 3,3-bis(difluoromethyl)cyclopropenes in short order. resulting cyclopropene products are readily reduced corresponding orphaned under hydrogenation conditions. Quantum chemical calculations reveal nature cleavage steps provide evidence for catalysis boron not silylated oxonium ions, though Si-F formation enthalpic driving force reaction.

Язык: Английский

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C−F Bond Insertion: An Emerging Strategy for Constructing Fluorinated Molecules

Chemistry - A European Journal, Год журнала: 2024, Номер 30(20)

Опубликована: Янв. 25, 2024

C-F Insertion reactions, where an organic fragment formally inserts into a carbon-fluorine bond in substrate, are highly attractive, yet largely unexplored, methods to prepare valuable fluorinated molecules. The inherent strength of bonds and the resulting need for large thermodynamic driving force initiate cleavage often leads sequestering released fluoride unreactive by-product. Recently, however, several groups have succeeded overcoming this challenge, opening up study insertion as efficient atom-economical approach compounds. In article, recent breakthroughs discussed focusing on key conceptual advances that allowed both subsequent incorporation product.

Язык: Английский

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eFluorination for the Rapid Synthesis of Carbamoyl Fluorides from Oxamic Acids

Organic Letters, Год журнала: 2024, Номер 26(29), С. 6103 - 6108

Опубликована: Июль 17, 2024

In this letter, we disclose the anodic oxidation of oxamic acids in presence Et3N·3HF as a practical, scalable, and robust method to rapidly access carbamoyl fluorides from readily available stable precursors. The simplicity also led us develop first flow electrochemical preparation fluorides, demonstrating scale-up feasibility proof concept.

Язык: Английский

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Facile Synthesis of Carbamoyl Fluorides via N-Carbamoylimidazole Activation

ACS Omega, Год журнала: 2025, Номер 10(7), С. 6908 - 6917

Опубликована: Фев. 14, 2025

The untapped potential of carbamoyl fluorides for various chemico/biological applications is hampered by the scarcity straightforward and benign methods their synthesis. In this report, we disclose a novel mild three-step procedure that avoids exotic, corrosive, highly toxic reagents. Briefly, commercially available secondary amines are carbamoylated with 1,1′-carbonyldiimidazole, followed alkylation to improve nucleofugality, exchange inorganic KF. This works on gram scale without chromatographic purification. It however limited basic, sterically unhindered alkylation-prone functional groups.

Язык: Английский

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Fluoride-Catalyzed Cross-Coupling of Carbamoyl Fluorides and Alkynylsilanes

Organic Letters, Год журнала: 2023, Номер 25(40), С. 7369 - 7373

Опубликована: Сен. 28, 2023

We report the synthesis of alkynamides via cross-coupling carbamoyl fluorides and alkynylsilanes catalyzed by tetrabutylammonium fluoride (TBAF). In contrast to previously reported transformations fluorides, C-F bond cleavage is achieved under exceptionally mild conditions (room temperature, low catalyst loadings, short reaction times) without need for strongly nucleophilic reagents and/or catalysts. This method offers distinct advantages over transition-metal-catalyzed approaches, such as tolerance aryl halide moieties complementary chemoselectivity.

Язык: Английский

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Catalytic Synthesis of Carbonyl Compounds Using Acyl Fluorides, Carbamoyl Fluorides, and Fluoroformates: An Overview

Asian Journal of Organic Chemistry, Год журнала: 2024, Номер 13(5)

Опубликована: Фев. 1, 2024

Abstract Acyl fluorides, carbamoyl fluorides and fluoroformates have been employed as efficient reagents in a number of organic syntheses. Their application catalytic transformations, however, began to be explored the early 2000s. Recently, these increasingly gained attention owing their unique reactivity diverse systems. This review aims overview advancements development processes, including transition‐metal catalysis, organocatalysis, cooperative NHC/photoredox where organofluorine compounds are acyl, carbamoyl, ester group donors.

Язык: Английский

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