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.
将有机锂或格氏试剂添加到(R)或(S)-O-(1-苯基丁基)醛肟1,在三氟化硼–二乙醚的存在下,形成具有良好到优异的二烯选择性的羟胺2。随后使用锌–醋酸–超声波 cleavage N–O 键,并形成氨基甲酸酯,得到N保护的胺3,具有良好的对映体纯度(77–100% ee)。当使用烯丙基溴化镁作为有机金属试剂时,得到的羟胺被转化为β-氨基酸衍生物4和γ-氨基醇5。