Asymmetric Domino Aza-Michael Addition/[3 + 2] Cycloaddition Reactions as a Versatile Approach to α,β,γ-Triamino Acid Derivatives
摘要:
Nonproteinogenic amino acids are prepared by an unprecedented domino aza-Michael addition-1,3-dipolar cycloaddition, leading to enantiopure highly substituted pyrrolidinopyrazolines. Nonaflyl azide serves as highly effective diazo transfer reagent, forming the link between the conjugate addition and cycloaddition steps. The resulting pyrrolidinopyrazolines can be rapidly transformed to either alpha,beta,gamma-triamino acids or 3,4-methano-beta-prolines. Peptide coupling can be regioselectively conducted at each of the amino groups.
Diastereoselective Formation of Trisubstituted Pyrrolidine-3-carboxylates
作者:Fabrice Denes、Fabrice Chemla、Jean F. Normant
DOI:10.1055/s-2002-31898
日期:——
Zinc enolates derived from the deprotonation of substituted β-(N-allyl)-aminoesters undergo smooth carbocyclization reaction to give, after reaction with electrophiles, 3,4-disubstituted-3-carbomethoxypyrrolidines with excellent stereochemical control.
Nonproteinogenic amino acids are prepared by an unprecedented domino aza-Michael addition-1,3-dipolar cycloaddition, leading to enantiopure highly substituted pyrrolidinopyrazolines. Nonaflyl azide serves as highly effective diazo transfer reagent, forming the link between the conjugate addition and cycloaddition steps. The resulting pyrrolidinopyrazolines can be rapidly transformed to either alpha,beta,gamma-triamino acids or 3,4-methano-beta-prolines. Peptide coupling can be regioselectively conducted at each of the amino groups.