Details
| Original language | English |
|---|---|
| Pages (from-to) | 1149-1160 |
| Number of pages | 12 |
| Journal | European Journal of Organic Chemistry |
| Issue number | 5 |
| Publication status | Published - 16 Feb 2004 |
Abstract
Alkyl iodides and α-amino aldehydes can be homologated to the corresponding methyl esters and β-amino methyl esters, including β-amino-α-hydroxy methyl esters, using lithiated (dimethoxymethyl) diphenylphosphane oxide. The primary α,α-(dimethoxy) diphenylphosphane oxides obtained by this Horner-Wittig type process collapse to give the target esters under proton-catalyzed conditions in the presence of water. Detailed and carefully conducted mechanistic studies revealed that the diphenylphosphane oxide group is activated by protonation, and acts as the initial leaving group in this process. In the cases of adducts derived from the reaction of the phosphane oxide-stabilized anion with α-amino aldehydes, homologation to the β-amino- and β-amino-α-hydroxy methyl esters can be achieved by KOtBu-mediated elimination to the intermediate O,O-ketene acetals. These may either be allowed to react with water under acidic conditions to yield the β-amino methyl esters, or may be treated under the Sharpless asymmetric dihydroxylation conditions to directly furnish the β-amino-α-hydroxy methyl esters.
Keywords
- Acylation, Aldehydes, Dihydroxylations, Horner-Wittig reactions, Mechanistic studies
ASJC Scopus subject areas
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemistry(all)
- Organic Chemistry
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In: European Journal of Organic Chemistry, No. 5, 16.02.2004, p. 1149-1160.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Acylation of alkyl halides and amino aldehydes with a phosphane oxide-based d1-synthon
AU - Brünjes, Marco
AU - Kujat, Christof
AU - Monenschein, Holger
AU - Kirschning, Andreas
PY - 2004/2/16
Y1 - 2004/2/16
N2 - Alkyl iodides and α-amino aldehydes can be homologated to the corresponding methyl esters and β-amino methyl esters, including β-amino-α-hydroxy methyl esters, using lithiated (dimethoxymethyl) diphenylphosphane oxide. The primary α,α-(dimethoxy) diphenylphosphane oxides obtained by this Horner-Wittig type process collapse to give the target esters under proton-catalyzed conditions in the presence of water. Detailed and carefully conducted mechanistic studies revealed that the diphenylphosphane oxide group is activated by protonation, and acts as the initial leaving group in this process. In the cases of adducts derived from the reaction of the phosphane oxide-stabilized anion with α-amino aldehydes, homologation to the β-amino- and β-amino-α-hydroxy methyl esters can be achieved by KOtBu-mediated elimination to the intermediate O,O-ketene acetals. These may either be allowed to react with water under acidic conditions to yield the β-amino methyl esters, or may be treated under the Sharpless asymmetric dihydroxylation conditions to directly furnish the β-amino-α-hydroxy methyl esters.
AB - Alkyl iodides and α-amino aldehydes can be homologated to the corresponding methyl esters and β-amino methyl esters, including β-amino-α-hydroxy methyl esters, using lithiated (dimethoxymethyl) diphenylphosphane oxide. The primary α,α-(dimethoxy) diphenylphosphane oxides obtained by this Horner-Wittig type process collapse to give the target esters under proton-catalyzed conditions in the presence of water. Detailed and carefully conducted mechanistic studies revealed that the diphenylphosphane oxide group is activated by protonation, and acts as the initial leaving group in this process. In the cases of adducts derived from the reaction of the phosphane oxide-stabilized anion with α-amino aldehydes, homologation to the β-amino- and β-amino-α-hydroxy methyl esters can be achieved by KOtBu-mediated elimination to the intermediate O,O-ketene acetals. These may either be allowed to react with water under acidic conditions to yield the β-amino methyl esters, or may be treated under the Sharpless asymmetric dihydroxylation conditions to directly furnish the β-amino-α-hydroxy methyl esters.
KW - Acylation
KW - Aldehydes
KW - Dihydroxylations
KW - Horner-Wittig reactions
KW - Mechanistic studies
UR - http://www.scopus.com/inward/record.url?scp=4544362850&partnerID=8YFLogxK
U2 - 10.1002/ejoc.200300631
DO - 10.1002/ejoc.200300631
M3 - Article
AN - SCOPUS:4544362850
SP - 1149
EP - 1160
JO - European Journal of Organic Chemistry
JF - European Journal of Organic Chemistry
SN - 1434-193X
IS - 5
ER -