24180-12-9Relevant academic research and scientific papers
Diastereoselective synthesis of β-amino acid derivatives from dihydropyridones
Ege, Markus,Wanner, Klaus T.
, p. 7273 - 7282 (2008/12/20)
A new method for the diastereoselective preparation of stereoisomeric 2,3-disubstituted β-amino acids is presented. It is based on trans- and cis-2,3-disubstituted dihydropyridones, which were derived from 2-monosubstituted N-acyl dihydropyridone derivatives. Alkylation of the enolates of 2-substituted dihydropyridones gave trans-2,3-disubstituted dihydropyridones with high diastereoselectivities. Inversion of the stereocenter at C-3 of the dihydropyridone nucleus by a deprotonation/reprotonation sequence yielded the stereoisomeric cis-2,3-disubstituted dihydropyridones in high yields and diastereoselectivities. Following removal of the N-acyl protective group, oxidative degradation of the resulting cis- or trans-2,3-disusbtituted dihydropyridones, respectively, by sodium periodate led to the corresponding diastereomeric β-amino acids.
Mild and efficient deprotection of the amine protecting p-methoxyphenyl (PMP) group
Verkade, Jorge M.M.,van Hemert, Lieke J.C.,Quaedflieg, Peter J.L.M.,Alsters, Paul L.,van Delft, Floris L.,Rutjes, Floris P.J.T.
, p. 8109 - 8113 (2007/10/03)
Mild and efficient procedures for deprotection of the amine nitrogen protecting p-methoxyphenyl (PMP) group are described. Periodic acid and trichloroisocyanuric acid (TCCA) were found to be particularly effective in realizing amine liberation using 1 and 0.5 equiv of the oxidant, respectively. Extension of the periodic acid-mediated conditions to simultaneous alcohol oxidation by combination with a catalytic amount of sodium dichromate led to smooth conversion of PMP-protected Mannich products into the corresponding β-amino acids in a one-pot procedure.
Anionic Inverse Electron-Demand 1,3-Dipolar Cycloaddition of Nitrones with Ynolates. Facile Stereoselective Synthesis of 5-Isoxazolidinones Leading to β-Amino Acids
Shindo, Mitsuru,Itoh, Kotaro,Tsuchiya, Chinatsu,Shishido, Kozo
, p. 3119 - 3121 (2007/10/03)
(Equation Presented) The inverse electron-demand 1,3-dipolar cycloaddition of nitrones with ynolates, followed by quenching with t-BuOH, produced substituted 5-isoxazolidinones with good trans-selectivity. These products were easily converted into β-amino
A new and expeditious strategy for the synthesis of β-amino acids from Δ2-oxazolines
Fustero, Santos,Díaz, Ma Dolores,Navarro, Antonio,Salavert, Esther,Aguilar, Enrique
, p. 703 - 712 (2007/10/03)
A new, mild two-step synthesis of racemic β-amino acids starting from 2-alkyl-Δ2-oxazolines is described. The process implies the initial formation of masked N-substituted or N-unsubstituted β-enamino acid derivatives followed by chemoselective reduction of the enamino moiety. The process takes place with high yields, total chemoselectivity and moderate diastereoselectivity.
Diastereoselective Hydrogenation of Methyl 2-acrylate Catalyzed by Ru(II) or Rh(I) Complexes
Yamamoto, Keiji,Takagi, Masatoshi,Tsuji, Jiro
, p. 319 - 321 (2007/10/02)
The title compound was prepared and hydrogenated by using a Ru(II)- or Rh(I)-phosphine catalyst precursor with excellent anti-selectivity, the results indicating that a ligating group, NHCO2Me, may direct the addition of hydrogen to an olefinic diastereof
