O. Itoh et A. Amano, Friedel-Crafts alpha-aminoacylation of aromatic compounds with a chiral N-carboxy-alpha-amino acid anhydride (NCA); Part 2, SYNTHESIS-S, (3), 1999, pp. 423-428
The N-carboxy-alpha-amino acid anhydrides (NCA) derived from L-Asp(OEt). L-
Glu(OMe), L-Met, and L-Pro reacted with aromatic compounds (toluene or benz
ene) in the presence of AlCl3 to afford the corresponding alpha-aminoalkyl
aryl ketones as hydrochloride salts in moderate yields. The beta- and gamma
-amino acid esters, which were obtained from the reaction of the aromatic c
ompounds with L-Asp(OEt)- and L-Glu(OMe)-NCA, were hydrolyzed by hydrochlor
ic acid to the corresponding beta- and gamma-amino acids as hydrochloride s
alts. L-Phe-NCA did not react with benzene in the presence of AlCl3, instea
d an intramolecular acylation occurred to afford (S)-2-aminoindanone hydroc
hloride. The chiralities of the original L-a-amino acids were most retained
during these alpha-aminoacylation.