Taming nonclassical carbocations to control small ring reactivity

Science Advances, Journal Year: 2024, Volume and Issue: 10(2)

Published: Jan. 12, 2024

Prediction of the outcome ring opening small organic rings under cationic conditions can be challenging due to intermediacy nonclassical carbocations. For example, solvolysis cyclobutyl or cyclopropylmethyl derivatives generates up four products on nucleophilic capture elimination via cyclopropylcarbinyl and bicyclobutonium ions. Here, we show that such reaction outcomes controlled by subtle changes structure carbocation. Using bicyclo[1.1.0]butanes as cation precursors, regio- stereochemistry is shown depend degree nature substituents intermediates. Reaction are rationalized using computational models, resulting in a flowchart predict product formation from given precursor.

Language: Английский

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Precision single-atom editing: new frontiers in nitrogen insertion and substitution for the generation of N-heterocycles

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(14), P. 4041 - 4053

Published: Jan. 1, 2024

This paper primarily focuses on the editing of nitrogen atoms, encompassing insertion N, substitution C with and utilization 15 N in place 14 for construction N-heterocycles.

Language: Английский

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Stereospecific molecular rearrangement via nucleophilic substitution at quaternary stereocentres in acyclic systems

Nature Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 19, 2025

Language: Английский

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Bioinspired intramolecular spirocyclopropanation of quinones as an interrupted photoredox process

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(20), P. 5703 - 5711

Published: Jan. 1, 2024

Small molecules, such as trimethylamine N -oxide, interrupt intramolecular photoreactions of quinones by proton transfer and allow to convert a variety spirocyclopropanes in catalytic, diastereoselective, atom-conserving manner.

Language: Английский

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Biomimetic Synthesis of Azorellolide via Cyclopropylcarbinyl Cation Chemistry

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 18, 2024

A concise synthesis of the complex diterpene azorellolide, inspired by speculations on biosynthetic cationic cascades, is presented. The approach, guided computation, relies intramolecular interception a cyclopropylcarbinyl cation an appended carboxylate. successful execution this strategy was achieved through acid-catalyzed isomerization β-lactone in competition with type I dyotropic rearrangement.

Language: Английский

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Formally Stereoretentive S_N1 Reactions of Homoallylic Tertiary Alcohols Via Nonclassical Carbocation

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: May 27, 2025

We present a stereoretentive nucleophilic substitution of homoallylic tertiary alcohols via the formation nonclassical cyclopropyl carbinyl (CPC) carbocation intermediate. This strategy enables creation highly congested centers with preserved stereocontrol, addressing typical challenges instability and reactivity in SN1 mechanisms. The stabilization CPC intermediate is crucial for achieving precise regio- stereoselectivity, significantly enhancing utility SN1-type mechanisms complex molecule synthesis.

Language: Английский

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Visible-Light-Photocatalyzed Self-Cyclopropanation Reactions of Dibenzoylmethanes for the Synthesis of Cyclopropanes

Organic Letters, Journal Year: 2024, Volume and Issue: 26(27), P. 5752 - 5757

Published: July 1, 2024

A new self-cyclopropanation of 1,3-diphenylpropane-1,3-dione, leading to tetrasubstituted cyclopropane containing three contiguous stereogenic centers with high stereoselectivity, has been achieved through violet-light-emitting diode-irradiated photocatalysis, featuring both cycloaddition and a distinctive rearrangement. Diverging from conventional cyclopropanation pathways, this reaction yields unprecedented rearrangement cascade reactions.

Language: Английский

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Photoredox-Catalyzed Regioselective 1,3-Alkoxypyridylation of gem-Difluorocyclopropanes

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 4, 2024

Difluoromethylene and pyridine cores are very important structural units in medicinal chemistry. Herein, we report the development of photoredox-catalyzed ring-opening 1,3-alkoxypyridylation gem-difluorinated cyclopropanes using 4-cyanopyrines alcohols, employing cyclopropane radical cations as key intermediate. The reaction exhibits high regioselectivity under mild conditions can also be practiced on gram-scale synthesis, telescoped reaction, late-stage functionalization biological molecules.

Language: Английский

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Halogen Promoted Desulfurative Cleavage of Cyclopropylmethyl Thioethers and Amination of the Formed Cyclopropylcarbinyl Cations

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(20)

Published: March 20, 2024

Abstract Cyclopropylmethyl sulfides react with N ‐fluorosulfonimide (NFSI) or molecular iodine, enabling C−S cleavage to generate cyclopropylcarbinyl cations, which evolve through cyclopropane ring‐opening reactions into homoallyl cations suitable nucleophiles present in the reaction media. This desulfurative of cyclopropylmethyl thioethers under non‐acidic conditions facilitates homoallylation ‐based such as alkyl aryl amines well sulfonimides a one‐pot protocol one two steps depending on nucleophile. The is initiated by halogen‐sulfur bond that causes cleavage. Moreover, iodine proceeds iodide intermediates.

Language: Английский

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Strategic convergent synthesis en route to Veratrum steroidal alkaloids

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(14), P. 4014 - 4023

Published: Jan. 1, 2024

In this Highlight, the convergent synthetic approaches that yield highly functionalized, complex molecular architecture of Veratrum steroidal alkaloids are discussed.

Language: Английский

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