Chiral oxime ethers in asymmetric synthesis. Part 4. Asymmetric synthesis of N-protected amines and β-amino acids by the addition of organometallic reagents to ROPHy/SOPHy-derived aldoximes
Chiral oxime ethers in asymmetric synthesis. Part 4. Asymmetric synthesis of N-protected amines and β-amino acids by the addition of organometallic reagents to ROPHy/SOPHy-derived aldoximes
Addition of Allylmagnesium Bromide to ROPHy/SOPHy Aldoximes: Asymmetric Synthesis of Protected β-Amino Acids
作者:Christopher J. Moody、James C. A. Hunt
DOI:10.1055/s-1998-1767
日期:1998.7
A new asymmetric synthesis of protected β-amino acids is described in which the key step is the diastereoselective addition of allylmagnesium bromide to O-(1-phenylbutyl) aldoximes.
Chiral oxime ethers in asymmetric synthesis. Part 4. Asymmetric synthesis of N-protected amines and β-amino acids by the addition of organometallic reagents to ROPHy/SOPHy-derived aldoximes
作者:James C. A. Hunt、Cephas Lloyd、Christopher J. Moody、Alexandra M. Z. Slawin、Andrew K. Takle
DOI:10.1039/a907186e
日期:——
Addition of organolithium or Grignard reagents to (R)- or (S)-O-(1-phenylbutyl)aldehyde oximes 1 in the presence of boron trifluorideâdiethyl ether results in the formation of hydroxylamines 2 in good to excellent diastereoselectivity. Subsequent cleavage of the NâO bond with zincâacetic acidâultrasound, and carbamate formation, gives N-protected amines 3 in good enantiomeric purity (77â100% ee). When allylmagnesium bromide was used as the organometallic reagent, the resulting hydroxylamines were converted into β-amino acid derivatives 4 and γ-amino alcohols 5.