There is provided a novel process for the preparation of a dipeptide represented by the formula: ##STR1## wherein Ar represents an aromatic group; R.sup.1 represents a hydrogen atom, an alkyl group or an aryl group; R.sup.2 represents a hydrogen atom, an alkyl group or an aromatic group; Y represents a hydroxy group, an amino group or an acylamino group, which comprises subjecting a .beta.-lactam compound represented by the formula: ##STR2## wherein Ar, R.sup.1 and R.sup.2 have the same meanings as defined above, and X represents a hydroxy group, an amino group or an acylamino group, an azido group or a benzyloxy group, to hydrogenolysis in the presence of a catalyst. The process can be practiced without any complicated procedure as seen in the conventional processes for the preparation of peptides.
Selective deprotection of phthalyl protected amines
作者:Colleen A. Costello、Adam J. Kreuzman、Milton J. Zmijewski
DOI:10.1016/0040-4039(96)01752-2
日期:1996.10
Phthalyl amidase selectively deprotects phthalimido groups under very mild aqueous conditions in a one-pot reaction to produce phthalic acid and the free amine. The enzyme has been shown to deprotect several primary amines of distinctly different structure, and exhibits chiral selectivity when the substrate contains extensive β-branching. The enzyme has a definite requirement for ortho positioning
作者:Mikhail V. Rekharsky、Hatsuo Yamamura、Chika Inoue、Masao Kawai、Issey Osaka、Ryuichi Arakawa、Kouhei Shiba、Akihiro Sato、Young Ho Ko、Narayanan Selvapalam、Kimoon Kim、Yoshihisa Inoue
DOI:10.1021/ja063323p
日期:2006.11.1
For the first time, achiral cucurbiturils (CBs) were endowed with significant enantiomeric and distereomeric discrimination by incorporating a strong chiral binder. Calorimetric, nuclear magnetic, light-scattering, and mass spectral studies revealed that (S)-2-methylbutylamine (as a strong binder) can be discriminated by two enantiomeric supramolecular hosts, composed of CB[6] and (R)- or (S)-2-methylpiperazine