Asymmetric Synthesis of β-Substituted α-Methyl-β-amino Esters by Mannich Reaction of (<i>S</i>,<i>S</i>)-(<i>+</i>)-Pseudoephedrine Acetamide Derived Enolate with Imines
作者:Jose L. Vicario、Dolores Badía、Luisa Carrillo
DOI:10.1021/ol0155384
日期:2001.3.1
[reaction: see text]. The reaction of an (S,S)-(+)-pseudoephedrine acetamide based enolate with several imines afforded smoothly and with full stereochemical control a series of beta-substituted alpha-methyl-beta-aminoamides that upon hydrolysis/esterification afforded the corresponding beta-aminoester derivatives in good yields and in almost enantiomerically pure form.
The Mannich reaction of variously substituted (+)-(S,S)-pseudoephedrine amides with either enolizable and nonenolizable imines smoothly afforded a series of β-substituted α-alkyl-β-amino amides with full stereochemical control. These Mannich adducts have been converted into several synthetically useful chiral building blocks like β-amino esters, β-amino acids, and β-lactams using very simple and high-yielding