220117-36-2Relevant academic research and scientific papers
Synthesis of chiral β2-amino acids by asymmetric hydrogenation
Luehr, Susan,Holz, Jens,Zayas, Odalys,Wendisch, Volkmar,Boerner, Armin
, p. 1301 - 1319 (2012/11/07)
The synthesis of chiral β2-amino acids by homogeneous asymmetric hydrogenation is discussed. Prochiral β-aryl- or β-hetaryl-α-N-benzyl/N-acetyl/N-Boc substituted α- aminomethylacrylates used as substrates were prepared by a Baylis-Hillman react
EPC-synthesis of β-amino acid derivatives through lithiated hydropyrimidines
Seebach, Dieter,Boog, Alois,Schweizer, W. Bernd
, p. 335 - 360 (2007/10/03)
Racemic and enantiopure 2-tert-butyltetrahydropyrimidinones (from pivalaldehyde and 3-aminocarboxylic acids) are converted to Alloc-, Boc-, and Z-protected cyclic imino esters (7-10, Schemes 2-4). These are deprotonated to Li enaminates (K, L). Reactions with electrophiles (prim., sec. alkyl, allyl, benzyl, propargyl halides, aldehydes, imines, enoates) give good yields and are highly diastereoselective (products 11-42, Schemes 5-10). A two-step cleavage (removal of protecting group and hydrolysis) under very mild conditions converts the heterocyclic products to α-branched β-amino acid methyl esters (43-61, Schemes 11-13). The structure of the products is determined by NMR spectroscopy (Figure 1), by chemical correlation (Scheme 14), and by X-ray analysis (Figure 2, 3, 7, Table 1). A structure of the Li enaminates is proposed (Figure 4). Mechanistic models are derived for the reactions occurring with formation of two stereogenic centers with relative topicity like (Figures 5, 6).
Resolution of 4-phenyl-2-pyrrolidinone: A versatile synthetic intermediate
Zelle
, p. 1023 - 1026 (2007/10/02)
A resolution of 4-phenyl-2-pyrrolidinone is described. The resulting enantiomerically pure pyrrolidinones are exploited as precursor to 3-phenylpyrrolidines and 3-phenyl-γ-amino acids (4-amino-3-phenylbutanoic acid derivatives).
