Reaction of N-Acyl-Α-triphenylphosphonio-Α-amino Acid Esters with Organic Bases: Mechanism of the Base-Catalyzed Nucleophilic Substitution of the Triphenylphosphonium Group
作者:Roman Mazurkiewicz、Mirosława Grymel
DOI:10.1007/s007060200090
日期:2002.9.1
-acyl-α-triphenylphosphonio-α-amino acid esters with quaternary α-carbon, the α-substituted homologues of the N -acyliminoacetates were detected to be the only primary reaction product which, however, can undergo further tautomerization to the corresponding α,β-dehydro-α-amino acid derivatives. In both these cases the reaction of N -acyl-α-triphenylphosphonio-α-amino acid esters with nucleophiles proceeds via
-acyliminoacetates and N- acyl-α-triphenylphosphoranylideneglycinates. Wittig reaction of the latter ylides with aromatic and aliphatic aldehydes or ketones enables a new easy entry to N -acyl-α,β-dehydro-α-aminoacid esters.