Acylation of 1,5-Cyclooctadiene with Pivaloyl Tetrafluoroborate. Stereoselective Synthesis of endo-2-Pivaloyl-endo-8- hydroxybicyclo[3.3.0]octane. Study of the Reaction Mechanism

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

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ChemInform Abstract: Acylation of 1,5-Cyclooctadiene with Pivaloyl Tetrafluoroborate. Stereoselective Synthesis of endo-2-Pivaloyl-endo-8-hydroxybicyclo(3.3. 0)octane. Study of the Reaction Mechanism.

ChemInform ◽

10.1002/chin.199615101 ◽

2010 ◽

Vol 27 (15) ◽

pp. no-no

Author(s):

I. D. GRIDNEV

Keyword(s):

Reaction Mechanism ◽

Stereoselective Synthesis

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Stereoselective Synthesis of Highly-Congested Tetralin-Fused Spirooxindoles with Hydroxyl Group: Net Oxygen Atom Induced Hydride Shift/cyclization Process.

10.26434/chemrxiv.14616882 ◽

2021 ◽

Author(s):

Dan Sakai ◽

mizuki machida ◽

Keiji Mori

Keyword(s):

Reaction Mechanism ◽

Nitrogen Atom ◽

Oxygen Atom ◽

Stereoselective Synthesis ◽

Hydroxyl Group ◽

Target Structure ◽

Hydride Shift ◽

Cyclization Process ◽

Stereogenic Centers

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

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Stereoselective Synthesis of Multisubstituted Cyclohexanes by Reaction of Conjugated Enynones with Malononitrile in the Presence of LDA

Molecules ◽

10.3390/molecules25245920 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5920

Author(s):

Anastasiya V. Igushkina ◽

Alexander A. Golovanov ◽

Irina A. Boyarskaya ◽

Ilya E. Kolesnikov ◽

Aleksander V. Vasilyev

Keyword(s):

Reaction Mechanism ◽

Quantum Chemical Calculations ◽

Relative Stability ◽

Quantum Chemical ◽

Room Temperature ◽

Stereoselective Synthesis ◽

Dft Method ◽

Lithium Diisopropylamide ◽

Reaction Conditions

Reaction of linear conjugated enynones, 1,5-diarylpent-2-en-4-yn-1-ones, with malononitrile in the presence of lithium diisopropylamide LDA, as a base, in THF at room temperature for 3–7 h resulted in the formation of the product of dimerization, multisubstituted polyfunctional cyclohexanes, 4-aryl-2,6-bis(arylethynyl)-3-(aryloxomethyl)-4-hydroxycyclohexane-1,1-dicarbonitriles, in yields up to 60%. Varying the reaction conditions by decreasing time and temperature and changing the ratio of starting compounds (enynone and malononitrile) allowed isolating some intermediate compounds, which confirmed a plausible reaction mechanism. The relative stability of possible stereoisomers of such cyclohexanes was estimated by quantum chemical calculations (DFT method). The obtained cyclohexanes were found to possess photoluminescent properties.

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Arylation of enelactams using TIPSOTf: reaction scope and mechanistic insight

Organic Chemistry Frontiers ◽

10.1039/d0qo01396j ◽

2021 ◽

Author(s):

Tomasz J. Idzik ◽

Zofia M. Myk ◽

Łukasz Struk ◽

Magdalena Perużyńska ◽

Gabriela Maciejewska ◽

...

Keyword(s):

Reaction Mechanism ◽

Multinuclear Nmr ◽

Mechanistic Insight ◽

Nmr Study ◽

Wide Range

Triisopropylsilyltrifluoromethanesulfonate can be effectively used for the arylation of a wide range of enelactams. The multinuclear NMR study provided deep insights into the reaction mechanism.

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