Regiodivergent Ring-Expansion of Oxindoles to Quinolinones

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(7), P. 4301 - 4308

Published: Feb. 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.

Language: 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, Journal Year: 2023, Volume and Issue: 62(48)

Published: Oct. 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.

Language: Английский

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

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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

Chemical Science, Journal Year: 2024, Volume and Issue: 15(34), P. 13800 - 13806

Published: Jan. 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

Language: 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, Journal Year: 2023, Volume and Issue: 145(31), P. 17389 - 17397

Published: July 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.

Language: Английский

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

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(20)

Published: Jan. 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.

Language: Английский

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eFluorination for the Rapid Synthesis of Carbamoyl Fluorides from Oxamic Acids

Organic Letters, Journal Year: 2024, Volume and Issue: 26(29), P. 6103 - 6108

Published: July 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.

Language: Английский

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A ratiometric turn-on fluorescent probe for the detection of BF3 based on imidazole-quinoline

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Journal Year: 2025, Volume and Issue: 332, P. 125748 - 125748

Published: Jan. 13, 2025

Language: Английский

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Intramolecular Fluoroacylation Enabled by TrBF₄-Catalyzed Fluoride Recycling

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 27, 2025

Alkyne- and alkene-tethered acyl fluorides undergo intramolecular carbofluorination via fluoride recycling using catalytic TrBF4. Excellent stereoselectivity is observed for the alkyne addition, enabling access to novel fluorinated indan-2-ones (all ≥95:5 E/Z) cyclopentan-2-ones (85:15 E/Z). Fluorinated chroman-2-ones tertiary alkyl can also be synthesized this method, comparing favorably previously reported protocols that employ expensive metal catalysts under harsher conditions.

Language: Английский

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Facile Synthesis of Carbamoyl Fluorides via N-Carbamoylimidazole Activation

ACS Omega, Journal Year: 2025, Volume and Issue: 10(7), P. 6908 - 6917

Published: Feb. 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.

Language: Английский

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