1022985-41-6Relevant articles and documents
Amino acids and catalytic preparatory methods
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Page/Page column 8-10; 12, (2009/10/30)
The invention provides novel compounds and methods to carry out organocatalytic Michael additions of aldehydes to nitroethylene catalyzed by a proline derivative to provide α-substituted-γ-nitroaldehydes. The reaction can be rendered enantioselective when a chiral pyrrolidine catalyst is used, allowing for Michael adducts in nearly optically pure form (e.g., 96-99% e.e.). The Michael adducts can bear a single substituent or dual substituents adjacent to the carbonyl. The Michael adducts can be efficiently converted to protected γ2-amino acids, which are essential for systematic conformational studies of γ-peptide foldamers.
Peptide catalyzed asymmetric conjugate addition reactions of aldehydes to nitroethylene - A convenient entry into γ2-amino acids
Wiesner, Markus,Revell, Jefferson D.,Tonazzi, Sandro,Wennemers, Helma
, p. 5610 - 5611 (2008/12/22)
The peptide H-d-Pro-Pro-Glu-NH2 is a highly effective catalyst for conjugate addition reactions between aldehydes and nitroethylene. Only 1 mol % of H-d-Pro-Pro-Glu-NH2 and a 1.5-fold excess of aldehyde with respect to nitroethylene suffice to obtain γ-nitroaldehydes and, after reduction, monosubstituted γ-nitroalcohols in excellent yields and optical purities. The products can be readily converted into γ2-amino acids, thereby opening an effective direct entry into this important class of compounds. Copyright