An Ab initio Molecular Orbital Study on the Magnesium Controlled 1,3-Cycloaddition of Nitrile Oxides and Allylic Alcohols with Regio- and Stereoselectivity

Fukuda, Shohei; Kamimura, Akio; Kanemasa, Shuji; Hori, Kenzi

doi:10.1016/s0040-4020(00)00042-9

Cited by 20 publications

(16 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…B3LYP/6-311+G(d,p) + CPCM (dichloromethane)//B3LYP/6-31+G(d) transition structures for dipolar cycloaddition of 4 to 5 in the presence of MeMgBr(8). Energies are in kcal/mol.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Transition Structures of Diastereoselective 1,3-Dipolar Cycloadditions of Nitrile Oxides to Chiral Homoallylic Alcohols

2007

View full text Add to dashboard Cite

Transition structures of the 1,3-dipolar cycloaddition of substituted nitrile oxides with chiral homoallylic alcohols were explored with density functional theory (B3LYP/6-311+G(d,p)+CPCM(dichloromethane)//B3LYP/6-31+G(d)). The diastereoselectivity observed in these reactions was explained. The anti product is favored in both the thermal and magnesium-mediated reactions. Selectivity is predicted to increase in the presence of magnesium, in agreement with experimental results. The energetics of the magnesium-mediated reaction are similar to those previously found for allylic alcohols. [structure: see text].

show abstract

“…B3LYP/6-311+G(d,p) + CPCM (dichloromethane)//B3LYP/6-31+G(d) transition structures for dipolar cycloaddition of 4 to 5 in the presence of MeMgBr(8). Energies are in kcal/mol.…”

mentioning

confidence: 99%

“…This methodology has been useful for the synthesis of enantiopure β-hydroxy ketones and γ-amino alcohols . The mechanism and energetics of magnesium-mediated cycloadditions with allylic alcohols have been investigated quantum mechanically by Fukuda et al…”

mentioning

confidence: 99%

Transition Structures of Diastereoselective 1,3-Dipolar Cycloadditions of Nitrile Oxides to Chiral Homoallylic Alcohols

2007

View full text Add to dashboard Cite

show abstract

“…Nitrosocarbonyl intermediates 8 bearing encumbered aromatic substituents ( e. g ., Ar=mesitylene M , anthracene N ) are known to proceed in ene reactions along two competitive pathways according to the Markovnikov ( M ) and anti‐Markovnikov ( AM ) orientation (Scheme ) . The canon rule for these reactions is that they proceed straightforwardly to the ene adducts in accordance with the prevailing HOMO (olefin) ‐LUMO (nitrosocarbonyl) interaction ( M path), somewhat enforced by the polarization of the C=C double‐bond induced by the slightly electron withdrawing group CH 2 OH . The addition of the nitrogen atom to the less substituted olefinic carbon atom of 12 affords the ene adduct 13 preferentially or even exclusively …”

Section: Resultsmentioning

confidence: 99%

5‐Hydroxy‐isoxazolidine: A New Synthetic Approach to a Privileged Heterocycle for Organic Synthesis

2020

View full text Add to dashboard Cite

A modified pathway towards 5-hydroxy-isoxazolidines has been preliminarily investigated by taking advantage of the anti-Markovnikov route in ene reactions of sterically encumbered nitrosocarbonyl intermediates in the presence of allylsilylethers. Fluoride-mediated deprotection/cyclization of the ene adducts afforded the desired heterocycles in quantitative yields and the methodology is adaptable to a one-pot procedure.[a] Dr. Scheme 3. Synthesis of protected allylic alcohols as silylethers. Scheme 4. Ene reactions of mesito nitrosocarbonyl 8 M with allylsilylethers 16 a-c(A). Yields (%) of the isolated compounds 10, 17 and 18. Mes = 2,4,6-Me 3 Ph.

show abstract

“…In crotyl alcohol, the methyl and the hydroxymethylene groups are the substituents of the C=C bond and both concur to establish the polarization towards the C2 carbon atom as shown in Scheme 7. 7 The methyl group (C4) is a modest donor, while hydroxymethylene (C1) is slightly electron withdrawing. As a consequence, the electron-rich C2 carbon atom is apt to receive the addition of the electrophilic nitrosocarbonyl intermediate.…”

Section: Scheme 7 Substituent Effect On the C=c Bond Polarization In mentioning

confidence: 99%

N,O-Nucleosides from Ene Reaction of (Nitrosocarbonyl)mesitylene with Crotyl Alcohol: Selectivity, Scope, and Limitations

et al. 2017

View full text Add to dashboard Cite

The (nitrosocarbonyl)mesitylene intermediate undergoes an ene reaction with crotyl alcohol, affording two regioisomeric adducts in fair yields. The sterically demanding (nitrosocarbonyl)mesitylene slightly shifts the C2/Markovnikov orientation towards a C3/anti-Markovnikov pathway, affording a 5-hydroxyisoxazolidine that serves as a synthon for the preparation of N,O-nucleoside analogues through the Vorbrüggen protocol. The selectivity of the ene reaction is discussed in the light of C=C bond polarization and steric effects. The structures of the N,O-nucleosides are assigned and discussed on the basis of spectroscopic observations and X-ray analysis.

show abstract

An Ab initio Molecular Orbital Study on the Magnesium Controlled 1,3-Cycloaddition of Nitrile Oxides and Allylic Alcohols with Regio- and Stereoselectivity

Cited by 20 publications

References 25 publications

Transition Structures of Diastereoselective 1,3-Dipolar Cycloadditions of Nitrile Oxides to Chiral Homoallylic Alcohols

Transition Structures of Diastereoselective 1,3-Dipolar Cycloadditions of Nitrile Oxides to Chiral Homoallylic Alcohols

5‐Hydroxy‐isoxazolidine: A New Synthetic Approach to a Privileged Heterocycle for Organic Synthesis

N,O-Nucleosides from Ene Reaction of (Nitrosocarbonyl)mesitylene with Crotyl Alcohol: Selectivity, Scope, and Limitations

Contact Info

Product

Resources

About