Chemoselectivity of the CuAAC/Ring Cleavage/Cyclization Reaction between Enaminones and α-Acylketenimine

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(4), С. 2190 - 2199

Опубликована: Янв. 27, 2024

Ketenimines represent an important class of reactive species, useful synthetic intermediates, and synthons. However, in general, ketenimines preferentially undergoes nucleophilic addition reactions with hydroxyl amino groups, carbon functional groups remain a less studied subset such systems. Herein, we develop straightforward syntheses pyridin-4(1H)-imines that is achieved by cyclization reacting enaminone unit α-acylketenimine which generated from the sulfonyl azides terminal ynones situ (CuAAC/Ring cleavage reaction). The cascade process starts α-C instead group, attacking electron-deficient central ketenimine, chemoselectivity unconventional products were formed intramolecular cyclization.

Язык: Английский

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Controllable methylenation with ethylene glycol as the methylene source: bridging enaminones and synthesis of tetrahydropyrimidines

Organic Chemistry Frontiers, Год журнала: 2022, Номер 9(21), С. 5935 - 5941

Опубликована: Янв. 1, 2022

Controllable methylenation using renewable ethylene glycol as the methylene source has been developed for introduction of one or two building blocks.

Язык: Английский

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PhB(OH)₂-Promoted Electrochemical Sulfuration–Formyloxylation of Styrenes and Selectfluor-Mediated Oxidation–Olefination

Organic Letters, Год журнала: 2021, Номер 23(23), С. 9140 - 9145

Опубликована: Ноя. 16, 2021

We report a PhB(OH)2-promoted electrochemical sulfuration-formyloxylation reaction of styrenes employing commercially available thiophenols/thiols as thiolating agents. Specifically, metal catalysts and external chemical oxidants are not needed in the for formation β-formyloxy sulfides, these sulfides can be further converted to (E)-vinyl sulfones via Selectfluor-mediated oxidation-olefination. Notably, on basis this oxidation strategy, β-hydroxy sulfide, sulfoxide, sulfone, sulfoxide also easily prepared.

Язык: Английский

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Synthesis of Pyrrole via Formal Cycloaddition of Allyl Ketone and Amine under Metal-Free Conditions

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(18), С. 12482 - 12490

Опубликована: Сен. 2, 2022

A new metal-free synthesis of pyrrole from allyl ketone and amine has been established. The reaction proceeds via an thiolative activation the C–C double bond with dimethyl(methylthio)sulfonium trifluoromethanesulfonate, followed by a nucleophilic ring-opening addition primary to generated episulfonium intermediate, then internal condensation aromatization. This mild procedure provides novel strategy construction substituted pyrroles through formal [4 + 1] cycloaddition reaction.

Язык: Английский

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Copper-catalyzed three-component annulation toward pyrroles via the cleavage of two C–C bonds in 1,3-dicarbonyls

Chemical Communications, Год журнала: 2023, Номер 59(71), С. 10636 - 10639

Опубликована: Янв. 1, 2023

The first copper-catalyzed three-component annulation of α,β-unsaturated ketoximes, 1,3-dicarbonyls and paraformaldehyde has been documented. This novel strategy achieved the two C-C bond cleavage 1,3-dicarbonyl compounds directly as a single-carbon synthon provided new highly efficient method for synthesis 2,3-disubstituted pyrroles in moderate to good yields with broad functional group compatibility.

Язык: Английский

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Switchable Synthesis of Sulfoxides, Sulfones and Thiosulfonates through Selectfluor-Promoted Oxidation with H2O as O-Source

Synthesis, Год журнала: 2021, Номер 54(08), С. 1996 - 2004

Опубликована: Ноя. 19, 2021

Abstract A practical and efficient protocol for the switchable synthesis of sulfoxides, sulfones, thiosulfonates via Selectfluor-mediated oxidation sulfides thiols, respectively, at ambient temperature has been developed. All these organosulfur compounds can be prepared with nearly quantitative yields by applying eco-friendly H2O as O-source. The formation sulfoxides takes only a few minutes (3–20 min). As suggested control experiments, procedure might proceed through fluorination sulfide, nucleophilic addition H2O, elimination hydrogen fluoride.

Язык: Английский

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Synthesis of Polycyclic 3,3′-Biindoles via AgOTf-Catalyzed Nucleophilic Addition and Cycloisomerization

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(9), С. 6418 - 6425

Опубликована: Апрель 25, 2022

A method for the rapid synthesis of polycyclic 3,3'-biindole derivatives has been developed through AgOTf-catalyzed nucleophilic addition and cycloisomerization processes. The cascade reaction employs readily accessible indoles their N-2-formylphenyl provides functionalized 3,3'-biindoles in moderate to good yields under mild conditions. This is highly efficient takes only several minutes (∼5 min). Notably, also highlighted by a Selectfluor-mediated oxidation that quickly generates oxindole derivatives.

Язык: Английский

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Electrochemical Cyclization of Alkynyl Enaminones: Controllable Synthesis of Indeno[1,2-c]pyrroles or Indanones

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(16), С. 11131 - 11140

Опубликована: Авг. 4, 2022

We report an electrochemical intramolecular [3 + 2] cyclization of alkynyl enaminones in a user-friendly undivided cell under constant current conditions without oxidant and catalyst, indeno[1,2-c]pyrrole derivatives could be obtained good to excellent yields. Notably, preliminary substituent-controlled selective transformation is also achieved electrocatalysis alone, (R4 ≠ H) or indanone = prepared directly adding base heating process.

Язык: Английский

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Brønsted acid promoted synthesis of polysubstituted pyrroles from enamines/imines and diazopyruvates: a metal-free cascade approach

Green Synthesis and Catalysis, Год журнала: 2023, Номер unknown

Опубликована: Дек. 1, 2023

A Brønsted acid-promoted, metal-free cascade reaction of easily available enamines/imines with diazopyruvates has been demonstrated. With triflic acid as the promoter, proceeds smoothly at room temperature through sequential diazo protonation, nucleophilic enamine N-addition/C-addition and dehydrative aromatisation in a highly regioselective manner. Interestingly, regioselectivity is governed by unusual N-nucleophilic addition. The method provides an operationally trivial approach to synthesis multisubstituted pyrroles including tri-, tetra-, penta-substituted derivatives well N-H free diverse functionalities good yields under extraordinarily simple mild conditions. utility illustrated rapid assembly polysubstituted bispyrroles array diversely structured pyrrole derivatives.

Язык: Английский

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Selectfluor-Mediated Oxidative Dehydrogenation of Hydrazines: A Process for the Synthesis of Azo Compounds

Synthesis, Год журнала: 2022, Номер 54(23), С. 5245 - 5252

Опубликована: Июль 13, 2022

Abstract A facile method to synthesize azo compounds from hydrazine derivatives is developed. This represents the unprecedented example of Selectfluor-mediated oxidative dehydrogenation derivatives. The reaction might proceed through N-fluorination and elimination processes. protocol exhibits key features including simple operation, mild conditions, good functional group tolerance, high efficiency. Moreover, advantage also highlighted by conversion a sulfonyl-substituted compound furnish acetanilide in excellent yield under 4 W blue LED irradiation.

Язык: Английский

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