Superacid catalyzed ring-opening reactions involving 2-oxazolines and the role of superelectrophilic intermediates

@article{Klumpp2004SuperacidCR,
  title={Superacid catalyzed ring-opening reactions involving 2-oxazolines and the role of superelectrophilic intermediates},
  author={Douglas A. Klumpp and Rendy Rendy and Aaron McElrea},
  journal={Tetrahedron Letters},
  year={2004},
  volume={45},
  pages={7959-7961}
}
10 Citations

Lewis Acid-Catalyzed Nucleophilic Addition of Indoles to in Situ-Generated 2-Amidoallyl Cations.

The first Lewis acid-catalyzed generation of 2-amidoallyl cations through ring-opening of 4-benzylidene-2-oxazolines with Sc(OTf)3 is reported, which successfully applied to pyrroles and naphthols as π-nucleophiles.

Catalyst development for organocatalytic hydrosilylation of aromatic ketones and ketimines.

1-Isoquinolyl oxazoline, derived from mandelic acid, was identified as the most efficient catalyst of the series, capable of delivering high enantioselectivities in the reduction of both ketones and ketimines.

Anti-Markovnikov rearrangement in sulfur mediated allylic C-H amination of olefins.

Very rare cases of anti-Markovnikov rearrangement from secondary carbocations toward primary carbocations or primary triflates were observed during the study on sulfur mediated allylic C-H amination of olefins.

Bi(OTf)3-catalyzed diastereoselective S(N)1-type reactions of chiral propargylic acetates.

A highly diastereoselective, Bi(OTf)3-catalyzed reaction of chiral propargylic acetates with various weak carbon nucleophiles in which chiral carbocations are very likely to be involved as intermediates.

Molecular rearrangements of superelectrophiles

  • D. Klumpp
  • Chemistry, Biology
    Beilstein journal of organic chemistry
  • 2011
This review will describe these types of superelectrophilic reactions, which involve reaction steps similar to monocationic rearrangements, such as alkyl group shifts, Wagner–Meerwein shifts, hydride shifts, ring opening reactions, and other skeletal rearrangement-type reactions.

Highly diastereoselective Friedel-Crafts alkylation reactions via chiral alpha-functionalized benzylic carbocations.

A model is suggested to explain the facial diastereoselectivity based on a preferred conformation of the putative intermediate carbocation based on an analysis of chiral 1-aryl-1-alkanols subjected to an acid-catalyzed reaction with various arenes.

Superelectrophiles: charge-charge repulsive effects.

Over the years, a significant number of di- and tricationic superelectrophiles have been studied, and many exhibit charge-charge repulsive effects due to the interaction of the positive charges.

References

SHOWING 1-10 OF 12 REFERENCES

Superacid-catalyzed reactions of cinnamic acids and the role of superelectrophiles.

It is provided clear evidence that protonated carboxylic acid groups (or the corresponding acyl cation) can enhance the reactivity of an adjacent electrophilic center.

Dicationic intermediates involving protonated amides: dual modes of reactivity including the acylation of arenes.

In the Brønsted superacid CF( 3)SO(3)H (triflic acid), amides are able to form reactive, dicationic electrophiles that participate in two distinctly different types of electrophilic reactions.

Reaction of 2-methyl-2-oxazoline with trimethylsilyl initiators: an unusual mode of ring opening

The initiation and early stages of propagation in the cationic ring-opening polymerization of 2-methyl-2-oxazoline by Me 3 SiOSO 2 CF 3 and Me 3 SiI were investigated by 1 H NMR. The results indicate

Study on the Reaction of Isoxazolidine-3-thione with Anhydrous Aluminum CHloride; Synthesis and Mechanism of the Formation of N-(p-Biphenylyl)-3-aryl-3-phenylpropanothioamides

The reaction of 5-aryl-2-phenylisoxazolidine-3-thiones with more than 3 equivalents of anhydrous aluminum chloride in benzene at reflux gave N-(p-biphenylyl)-3-aryl-3-phenylpropanothioamides in good

Observations on the mechanism of the Pictet-Gams reaction

N-Acyl derivatives of 2-amino-I-phenylpropan-1-ol cyclise either to oxazolines or isoquinolines and since the oxazolines are readily converted into isoquinolines, their intermediacy in the

Preparation of Condensed Aromatics by Superacidic Dehydrative Cyclization of Aryl Pinacols and Epoxides1a

Aryl pinacols and epoxides, respectively, are cleanly and in high yield converted via superacidic dehydrative cyclization to the corresponding condensed aromatics. Dehydrative cyclization of

Reactions of 2-Benzyl-5-phenylisoxazolidine-3-thiones with Aromatics in the Presence of Anhydrous Aluminum Chloride: Synthesis of 3-Aryl-N-benzyl-3-phenylpropanothiohydroxamic Acids

2-Benzyl- and 2-(2-chlorobenzyl)-5-phenylisoxazolidine-3-thiones 1 and 2-benzyl-5-phenylisoxazolidin-3-one 2 react with aromatics such as toluene, biphenyl, p-xylene, and chlorobenzene in the

Electrophilic Aromatic Substitution

The Mechanism of Electrophilic Aromatic Substitution. Hydrogen Exchange. The Replacement of a Substituent by Hydrogen. Metallation. Reactions Involving Electrophilic Carbon. Reactions Involving

A comparison of the effectiveness of sulphuric acid and trifluoromethanesulphonic acid in Koch carboxylation reactions

Trifluoromethanesulphonic acid has been found to be far superior to 95% sulphuric acid for the carboxylation of olefins, alcohols, and esters with carbon monoxide at atmospheric pressure. This is