6.17 Polonovski- and Pummerer-type Reactions and the Nef Reaction

Bur, Scott K.

doi:10.1016/b978-0-08-097742-3.00626-1

Cited by 9 publications

(3 citation statements)

References 152 publications

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“…This phenomenon is considered to be the well-known autocatalytic degradation of NMO to morpholinium ions and N -formylmorpholine, as described earlier. 47 , 66 , 67 From the time course ( Figure S8 ), it is clear that the oxidation reaction stops when the concentration of NMM is larger than that of NMO, shifting the reaction equilibrium to the outside of the catalytic cycle (see Scheme 1 ). Therefore, we can conclude that the autocatalytic degradation of NMO is responsible for the early inhibition of catalyst turnover during the oxidation reaction.…”

Section: Resultsmentioning

confidence: 99%

Reusable Magnetite Nanoparticle (Fe₃O₄ NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Pincella,

Isozaki,

Sato

et al. 2024

ACS Omega

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Iron oxide nanoparticles (NPs) are nontoxic and abundant materials which have long been investigated as reusable catalysts in oxidation reactions, but their use so far has been hampered by a low selectivity. Here, unsupported iron oxide NPs have been found to successfully catalyze the microwave-assisted oxidation of primary and secondary alcohols to their respective aldehydes and ketones with a high selectivity when N-methylmorpholine N-oxide was used as the terminal oxidant. The crystalline phase and size of the iron-based catalyst have a drastic effect on its activity, with small magnetite (Fe 3 O 4 ) NPs being the optimal catalyst for this reaction. The nanocatalyst could be easily recovered by magnetoseparation and successfully recycled four times without any need for special pretreatment or reactivation step and with a minimal loss of activity. The subsequent loss of activity was attributed to the transition from magnetite (Fe 3 O 4 ) to maghemite (γ-Fe 2 O 3 ), as confirmed by X-ray diffraction, Fourier transform infrared, and X-ray absorption near-edge spectroscopy. The nanocatalyst could then be reactivated by the high-temperature microwave treatment and used again for the microwave-assisted oxidation reaction.

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Section: Resultsmentioning

confidence: 99%

Reusable Magnetite Nanoparticle (Fe₃O₄ NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Pincella,

Isozaki,

Sato

et al. 2024

ACS Omega

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“…We theorize that the cyclic nitrobenzene 4 might be formed through a Nef reaction (Scheme 4 ), 17 in which a molecule of nitromethane is converted into a nitronate salt VI through the action of the base. This salt leads to the respective iminium intermediate VIII , which might be attacked by one of the pendent hydroxy groups from the open nitrobenzene 3a , resulting in intermediate IX .…”

Section: Table 1 Optimization Of the Reaction Condition...mentioning

confidence: 99%

Mild Synthesis of Symmetric 3,5-Disubstituted Nitrobenzenes

Francisco

Sousa

Guieu

et al. 2022

Synlett

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A mild synthesis of 3,5-disubstituted nitrobenzenes from readily available 3-formylchromones is reported. The developed methodology follows a cascade process, promoted by diazobicyclo[5.4.0]undec-7-ene (DBU). The proposed mechanism would involve an initial Michael addition of nitromethane at C-2 of 3-formylchromone. The resultant intermediate would undergo another Michael reaction with a second 3-formylchromone. After ring closure through intramolecular cyclization, the aromatization would be completed by deformylation, affording the 3,5-disubstituted nitrobenzenes in 53-86% yield. The reported method produces three new C–C bonds in a simple and straightforward manner and it is consistent with gram-scale synthesis.

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“…The Nef reaction is a convenient method to convert readily available primary and secondary nitroalkanes into the corresponding aldehydes and ketones . The classic Nef reaction, reported in 1894, involves the basic treatment of a nitroalkane precursor to form a nitronate intermediate, which is then hydrolyzed to the carbonyl-containing product using a strong acid .…”

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confidence: 99%

Sequential Reduction of Nitroalkanes Mediated by CS₂ and Amidine/Guanidine Bases: A Controllable Nef Reaction

Guan

Schomaker

et al. 2019

Org. Lett.

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In this letter, we describe a mild, functional group-tolerant reductive Nef reaction that utilizes CS2 and an amidine or guanidine base to sequentially cleave N–O bonds. These conditions transform secondary nitroalkanes to ketones via an isolable oxime with minimal erosion at labile stereogenic carbons, show excellent compatibility with groups sensitive to oxidizing or reducing conditions, display good scalability, and are well-suited for generating useful 3-pyrrolidinone motifs from readily accessible 1,3-dipolar cycloaddition products.

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6.17 Polonovski- and Pummerer-type Reactions and the Nef Reaction

Cited by 9 publications

References 152 publications

Reusable Magnetite Nanoparticle (Fe₃O₄ NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Reusable Magnetite Nanoparticle (Fe₃O₄ NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Mild Synthesis of Symmetric 3,5-Disubstituted Nitrobenzenes

Sequential Reduction of Nitroalkanes Mediated by CS₂ and Amidine/Guanidine Bases: A Controllable Nef Reaction

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6.17 Polonovski- and Pummerer-type Reactions and the Nef Reaction

Cited by 9 publications

References 152 publications

Reusable Magnetite Nanoparticle (Fe3O4 NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Reusable Magnetite Nanoparticle (Fe3O4 NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Mild Synthesis of Symmetric 3,5-Disubstituted Nitrobenzenes

Sequential Reduction of Nitroalkanes Mediated by CS2 and Amidine/Guanidine Bases: A Controllable Nef Reaction

Contact Info

Product

Resources

About

Reusable Magnetite Nanoparticle (Fe₃O₄ NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Reusable Magnetite Nanoparticle (Fe₃O₄ NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation

Sequential Reduction of Nitroalkanes Mediated by CS₂ and Amidine/Guanidine Bases: A Controllable Nef Reaction