Oxime‐Mediated Oxychlorination and Oxybromination of Unactivated Olefins

Dong, Kuiyong; Qin, Haitao; Liu, Feng; Zhu, Chen

doi:10.1002/ejoc.201403538

Cited by 38 publications

(21 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In many instances, these methods not only require the use of transition metal catalysts, high temperature or toxic, costly, organic or inorganic oxidizing agents but also suffer from low to moderate yields. However, progress in the oxyhalogenation reaction has been made recently and examples include Pd, [15a] Fe [15b] Cu, [15c] or Al [15d] or TBHP [15e] mediated protocols. Further‐more, molecular bromine was applied in the cyclization, albeit with varying yields and the observation of side reactions [15f] .…”

Section: Figurementioning

confidence: 99%

Intramolecular Electrochemical Oxybromination of Olefins for the Synthesis of Isoxazolines in Batch and Continuous Flow

et al. 2021

View full text Add to dashboard Cite

A highly regioselective protocol for the synthesis of isoxazolines through cascade CÀ O and CÀ Br bond formation has been developed. The electrochemical approach uses traceless electrons as a sole source of oxidant, thus avoiding the use of stoichiometric organic or inorganic oxidants and provides a mild and environmentally benign alternative pathway for the synthesis of a wide range of valuable substituted isoxazolines from alkenyl oximes in good yields. Synthetic organic chemistry is considered a fast-developing field in science as it continuously provides new routes towards the synthesis of novel materials via green, sustainable, and economical techniques. [1,2] Electrochemical synthetic methods have gained increasing attention since they provide mild conditions, good functional group tolerance, high regioselectivity and chemoselectivity, and reduced waste by avoiding costly oxidants or reductants in favor of electricity. [3] Nitrogen-containing heterocycles are important building blocks and part of many commercial products. Among them, isoxazolines are an important class of heterocyclic compounds and their derivatives are frequently found in a wide range of natural products, biologically active compounds, agrochemicals, and pharmaceuticals. [4,5] (Figure 1) Moreover, isoxazolines can serve as versatile synthetic intermediates in organic chemistry. [6][7][8][9][10][11] Therefore, the development of sustainable methods providing isoxazolines and their derivatives remains an important target for synthetic organic chemists. Approaches for their synthesis range from the use of the 1,3-dipolar cycloaddition reactions of nitrile oxides with allyl halide [12,13] to oxyhalogenation of allylic oximes. [14,15] In many instances, these methods not only require the use of transition metal catalysts, high temperature or toxic, costly, organic or inorganic oxidizing agents but also suffer from low to moderate yields. However, progress in the oxyhalogenation reaction has been made recently and examples include Pd, [15a] Fe [15b] Cu, [15c] or Al [15d] or TBHP [15e] mediated protocols. Furthermore, molecular bromine was applied in the cyclization, albeit with varying yields and the observation of side reactions. [15f] Hence, the development of a simple, economically viable, and Communications

show abstract

Section: Figurementioning

confidence: 99%

Intramolecular Electrochemical Oxybromination of Olefins for the Synthesis of Isoxazolines in Batch and Continuous Flow

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The formation of the heterocycles, mainly isoxazolines/isoxazoles, from unsaturated oximes can be achieved through different ways including addition of electrophiles to the C=C double bond of the unsaturated oxime followed by intramolecular nucleophilic attack of the oxime group [97][98][99][100], metal-catalyzed cyclization [98,[101][102][103][104][105][106][107][108], cyclization under the action of photocatalysts [109,110], cyclization of nitroso intermediate [111], etc. [112,113].…”

Section: Application Of the Oxime Radicals In Organic Synthesis: Intrmentioning

confidence: 99%

Oxime radicals: generation, properties and application in organic synthesis

Krylov¹,

Paveliev²,

Budnikov³

et al. 2020

Beilstein J. Org. Chem.

View full text Add to dashboard Cite

N-Oxyl radicals (compounds with an N–O• fragment) represent one of the richest families of stable and persistent organic radicals with applications ranging from catalysis of selective oxidation processes and mechanistic studies to production of polymers, energy storage, magnetic materials design and spectroscopic studies of biological objects. Compared to other N-oxyl radicals, oxime radicals (or iminoxyl radicals) have been underestimated for a long time as useful intermediates for organic synthesis, despite the fact that their precursors, oximes, are extremely widespread and easily available organic compounds. Furthermore, oxime radicals are structurally exceptional. In these radicals, the N–O• fragment is connected to an organic moiety by a double bond, whereas all other classes of N-oxyl radicals contain an R2N–O• fragment with two single C–N bonds. Although oxime radicals have been known since 1964, their broad synthetic potential was not recognized until the last decade, when numerous selective reactions of oxidative cyclization, functionalization, and coupling mediated by iminoxyl radicals were discovered. This review is focused on the synthetic methods based on iminoxyl radicals developed in the last ten years and also contains some selected data on previous works regarding generation, structure, stability, and spectral properties of these N-oxyl radicals. The reactions of oxime radicals are classified into intermolecular (oxidation by oxime radicals, oxidative C–O coupling) and intramolecular. The majority of works are devoted to intramolecular reactions of oxime radicals. These reactions are classified into cyclizations involving C–H bond cleavage and cyclizations involving a double C=C bond cleavage.

show abstract

“…From the discovery of the DA reaction in the 1920s by Otto Diels and Kurt Alder [12], the new methods developed to give highly variable yields. Having low toxicity, ready availability, easy handling like iodine compounds, Iodobenzene (PhI) is the most utilized iodoarene, and m-chloroperbenzoic acid (mCPBA) and oxone are usually used as the terminal oxidants [13][14][15][16]. the lot of theoretical work has been devoted to the study of the mechanism and the selectivity of these cycloaddition reactions.…”

Section: Introductionmentioning

confidence: 99%

Understanding the Regioselective and Molecular Mechanism of the TCE in Cycloaddtion Reaction (TCE+Cp) and Addition Reaction (TCE+HCl) using DFT calculation

Zeroual¹,

Hajbi²

2016

Can Chem Trans

View full text Add to dashboard Cite

Abstract:The polar Diels-Alder (P-DA) reaction of TCE (2,3-Dicyano-but-2-enedinitrile), diene Cp, toward Bicyclo[2. 2. 1]hept-5-ene-2, 2, 3, 3-tetracarbonitrile , was theoretically studied using DFT methods at the B3LYP/ 6-31G(d) level and 6-31G(d,p) in the presence of water. Calculated relative enthalpy associated with the two feasible reactive channels indicate that this P-DA cycloaddition takes place via C2-C3 regioselectivity, furnishing a formal [4+2] P1 in excellent agreement with experimental outcomes. In the considered P-DA reaction, while C2-C3 regioselectivity can be explained using calculated Parr functions at the interacting sites of reagents. In addition, Hydrochloric acid does not react with the TCE (2,3-Dicyano-but-2-enedinitrile) due to the high activation energy of this reaction.

show abstract

Oxime‐Mediated Oxychlorination and Oxybromination of Unactivated Olefins

Cited by 38 publications

References 41 publications

Intramolecular Electrochemical Oxybromination of Olefins for the Synthesis of Isoxazolines in Batch and Continuous Flow

Intramolecular Electrochemical Oxybromination of Olefins for the Synthesis of Isoxazolines in Batch and Continuous Flow

Oxime radicals: generation, properties and application in organic synthesis

Understanding the Regioselective and Molecular Mechanism of the TCE in Cycloaddtion Reaction (TCE+Cp) and Addition Reaction (TCE+HCl) using DFT calculation

Contact Info

Product

Resources

About