Enantioselective Preparation of 2-Aminomethyl Carboxylic Acid Derivatives: Solving the 2-Amino Acid Problem with the Chiral Auxiliary 4-Isopropyl-5,5-diphenyloxazolidin-2-one (DIOZ). Preliminary Communication
作者:Dieter Seebach、Laurent Schaeffer、François Gessier、Pascal Bindschädler、Corinna Jäger、Delphine Josien、Sascha Kopp、Gérald Lelais、Yogesh R. Mahajan、Peter Micuch、Radovan Sebesta、Bernd W. Schweizer
DOI:10.1002/hlca.200390149
日期:2003.6
diastereoselectivities of 80 to >97% (Scheme). The primary products 2–8 thus obtained are converted to protected β2-amino acids by standard procedures (Table 1). Many of the DIOZderivatives are highly crystalline compounds (31 X-ray crystal structures in Table 2). The chiralauxiliaryDIOZ, readily prepared in either enantiomeric form, is recovered with high yield.
Benzyl<i>N</i>-[(Benzyloxy)methyl]carbamate: An Improved Aminomethylation Electrophile for the Synthesis of (Benzyloxy)carbonyl (Cbz)-Protected Chiral<i>β</i><sup>2</sup>-Amino Acids
作者:Cara E. Brocklehurst、Markus Furegati、J. Constanze D. Müller-Hartwieg、Flavio Ossola、Luigi La Vecchia
DOI:10.1002/hlca.200900401
日期:2010.2
step in the asymmetric synthesis of β2‐aminoacids, but it is unfortunately often accompanied by formation of transcarbamation by‐products. Aminomethylation was tested using a range of electrophiles, and the amount of by‐product formation was assessed in each case. Benzyl N‐[(benzyloxy)methyl]carbamate electrophile 3d is unable to form this by‐product due to its inherent benzyl substitution. Use of electrophile
作者:Müller-Hartwieg, J. Constanze D.、Vecchia, Luigi La、Meyer, Hartmut、Beck, Albert K.、Seebach, Dieter、Denmark, Scott E.、Duncan-Gould, Nathan、Hoover, Andrew