Effective Methods for the Synthesis ofN-Methylβ-Amino Acids from All Twenty Commonα-Amino Acids Using 1,3-Oxazolidin-5-ones and 1,3-Oxazinan-6-ones
作者:Andrew B. Hughes、Brad E. Sleebs
DOI:10.1002/hlca.200690235
日期:2006.11
N-Methyl β-amino acids are generally required for application in the synthesis of potentially bioactive modified peptides and other oligomers. Previous work highlighted the reductive cleavage of 1,3-oxazolidin-5-ones to synthesise N-methyl α-amino acids. Starting from α-amino acids, two approaches were used to prepare the corresponding N-methyl β-amino acids. First, α-amino acids were converted to
作者:Young K. Chen、Masanori Yoshida、David W. C. MacMillan
DOI:10.1021/ja063267s
日期:2006.7.1
The first enantioselectiveorganocatalytic amine conjugateaddition has been successfully developed. The application of LUMO-lowering iminium catalysis has enabled the highly chemo- and enantioselective 1,4-addition of a rationally designed N-silyloxycarbamate nucleophile (HOMO-raised) to alpha,beta-unsaturated aldehydes. Imidazolidinone 2*pTSA was found to catalyze the addition of various orthogonally