4181-11-7Relevant academic research and scientific papers
Asymmetric synthesis of N-protected amino acids by the addition of organolithium carboxyl synthons to ROPHy/SOPHy-derived aldoximes and ketoximes.
Cooper, Tracey S,Laurent, Pierre,Moody, Christopher J,Takle, Andrew K
, p. 265 - 276 (2007/10/03)
A new asymmetric synthesis of alpha-amino acids is described in which the key step is the highly diastereoselective addition of organolithium carboxyl synthons (2-furyllithium, phenyllithium, vinyllithium) to (R)- and (S)-O-(1-phenylbutyl) oximes to give hydroxylamines, with vinyllithium being the most satisfactory nucleophilic reagent. Subsequent reductive cleavage of the N-O bond in hydroxylamines, followed by N-protection, and oxidative cleavage of the carboxyl precursor gave a range of N-protected amino acids and esters. The method was exemplified by the synthesis of a range of derivatives of non-proteinogenic amino acids such as 4-bromophenylalanine, tert-leucine, norvaline, cyclohexyl- and aryl-glycines, 2-amino-8-oxodecanoic acid (Aoda) and alpha-methylvaline.
Studies of Regiospecific 3-Aza-Cope Rearrangement Promoted by Electrophilic Reagents
Barta, Nancy S.,Cook, Gregory R.,Landis, Margaret S.,Stille, John R.
, p. 7188 - 7194 (2007/10/02)
The 3-aza-Cope rearrangement of N-alkyl-N-allyl enamine substrates, which required temperatures of 250 deg C to proceed thermally, was promoted at 111 deg C in the presence of electrophilic reagents such as HCl (0.5 equiv), TiCl4 (0.2 equiv), AlMe3 (1.2 e
