Radical addition of nitrones to acrylates mediated by SmI<sub>2</sub>: asymmetric synthesis of γ-amino acids employing carbohydrate-based chiral auxiliaries

Johannesen, Sine A.; Albu, Silvia; Hazell, Rita G.; Skrydstrup, Troels

doi:10.1039/b405141f

Cited by 32 publications

(21 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Chiral auxiliaries have been used, either as substituents at the nitrone nitrogen atom or at the unsaturated ester or amide, to achieve enantioselectivity (Scheme ) 16. 17 The latter approach afforded up to 90:10 d.r. (for example, in the synthesis of γ‐hydroxyaminoester 33 ),16b while the former one gave moderate to very good enantioselectivity for N ‐benzyl‐type substituents16a and excellent enantioselectivity for N ‐glycosylnitrones, such as 34 17.…”

Section: Methodsmentioning

confidence: 99%

The Discovery of Novel Metal‐Induced Reactions of Nitrones: Not Only Electrophiles and Reagents for [3+2] Cycloadditions

2005

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

The Discovery of Novel Metal‐Induced Reactions of Nitrones: Not Only Electrophiles and Reagents for [3+2] Cycloadditions

2005

View full text Add to dashboard Cite

show abstract

“…Catalytic hydrogenation of diastereoisomerically pure anti-253 followed by N-protection with di(tert-butyl)dicarbonate (Boc) 2 O produced 255 in 82% yield, which is a key intermediate 109 in the synthesis of (S)-vigabatrin 2 (Scheme 57). 110 Recently, Skrydstrup et al 111 reported that the addition of chiral N-D D-mannose substituted nitrones 256a-d to n-butyl acrylate in the presence of SmI 2 to afford the c-amino acid derivatives 257a-d in moderate yield and 95:5 diastereoisomeric ratio, with predominance of diastereoisomer of (R)-configuration at the newly created stereogenic center (Scheme 58).…”

Section: C-substituted C-amino Acidsmentioning

confidence: 97%

“…111 Derivatives 257a-d and 259a-c are useful intermediates for the synthesis of c-substituted c-amino acids.…”

Section: C-substituted C-amino Acidsmentioning

confidence: 99%

Stereoselective synthesis of γ-amino acids

Ordóñez

Cativiela

2007

Tetrahedron: Asymmetry

247

View full text Add to dashboard Cite

“…with the major (R) diastereoisomer (Scheme 13.9) [19]. The same reaction when applied to N-D-ribose substituted nitrones (34) afforded the corresponding g-substituted-a-amino acid precursor (35) with opposite (S) configuration, indicating the choice of sugar nitrone as a tool for obtaining either (R) or (S) enantiomers.…”

Section: G-amino Acidsmentioning

confidence: 98%

Synthesis of γ‐ and δ‐Amino Acids

Trabocchi

Menchi

Guarna

2009

Amino Acids, Peptides and Proteins in Organic Chemistry

View full text Add to dashboard Cite

An area of significant importance that provides new dimensions to the field of molecular diversity and drug discovery is the area of peptidomimetics [1]. Biomedical research has reoriented towards the development of new drugs based on peptides and proteins, by introducing both structural and functional specific modifications, and maintaining the features responsible for biological activity. As a part of this research area, unnatural amino acids are of valuable interest in drug discovery and their use as new building blocks for the development of peptidomimetics with a high structural diversity level is of key interest. In particular, medicinal chemistry has taken advantage of the use of amino acid homologs to introduce elements of diversity for the generation of new molecules as drug candidates in the so-called peptidomimetic approach, where a peptide lead is processed into a new nonpeptidic molecule. The additional methylenic unit between the N-and C-termini in b-amino acids results in an increase of the molecular diversity in terms of the higher number of stereoisomers and functional group variety, and many synthetic approaches to the creation of b-amino acids have been published. There is great interest in these as a tool for medicinal chemistry [2] and in the field of b-peptides generally [3]. The g-and d-amino acids have garnered similar interest. In particular, the folding properties of g-[4] and d-peptides [5] have been investigated, as they have been proved to generate stable secondary structures. The homologation of a-amino acids into g-and d-units allows an enormous increase of the chemical diversity within the three and four atoms between the amino and carboxyl groups. Thus, additional substituents and stereocenters expand the number of compounds belonging to the class of g-and d-amino acids. g-Amino acids have been reported both in linear form, and with the amino and carboxyl groups separated or incorporated in a cyclic structure. In the case of d-amino acids, five-and six-membered rings have been mainly reported having two substituents variously tethered between the amino and carboxyl groups. Moreover, bicyclic and spiro compounds have been reported as constrained d-amino acids, especially in the field of peptidomimetics. The synthetic approaches for the preparation of

show abstract

Radical addition of nitrones to acrylates mediated by SmI₂: asymmetric synthesis of γ-amino acids employing carbohydrate-based chiral auxiliaries

Abstract: Alkyl nitrones possessing N-substituted sugars as chiral auxiliaries were found to effectively undergo an SmI(2)-mediated radical addition to n-butyl acrylate affording gamma-amino acid derivatives with high diastereomeric control.

Cited by 32 publications

References 11 publications

The Discovery of Novel Metal‐Induced Reactions of Nitrones: Not Only Electrophiles and Reagents for [3+2] Cycloadditions

The Discovery of Novel Metal‐Induced Reactions of Nitrones: Not Only Electrophiles and Reagents for [3+2] Cycloadditions

Stereoselective synthesis of γ-amino acids

Synthesis of γ‐ and δ‐Amino Acids

Contact Info

Product

Resources

About

Radical addition of nitrones to acrylates mediated by SmI2: asymmetric synthesis of γ-amino acids employing carbohydrate-based chiral auxiliaries

Abstract: Alkyl nitrones possessing N-substituted sugars as chiral auxiliaries were found to effectively undergo an SmI(2)-mediated radical addition to n-butyl acrylate affording gamma-amino acid derivatives with high diastereomeric control.

Cited by 32 publications

References 11 publications

The Discovery of Novel Metal‐Induced Reactions of Nitrones: Not Only Electrophiles and Reagents for [3+2] Cycloadditions

The Discovery of Novel Metal‐Induced Reactions of Nitrones: Not Only Electrophiles and Reagents for [3+2] Cycloadditions

Stereoselective synthesis of γ-amino acids

Synthesis of γ‐ and δ‐Amino Acids

Contact Info

Product

Resources

About

Radical addition of nitrones to acrylates mediated by SmI₂: asymmetric synthesis of γ-amino acids employing carbohydrate-based chiral auxiliaries