Pyroglutamic acid as a pseudoproline moiety: a facile method for its introduction into polypeptide chains
摘要:
The acylation of benzyl (S)-pyroglutamate is reported by reaction with the pentafluorophenyl ester of protected alanine and threonine. The H-1 NMR analysis of the acylated products shows that the alpha hydrogens of the protected amino acids are very deshielded. This effect is due to the presence of the carbonyl of the lactam ring and shows that the peptide bond is in the trans conformation. The deprotection of the amino acids is also reported. (C) 2001 Elsevier Science Ltd. All rights reserved.
Synthesis of N-trifluoromethyl amides from carboxylic acids
作者:Jianbo Liu、Matthew F.L. Parker、Sinan Wang、Robert R. Flavell、F. Dean Toste、David M. Wilson
DOI:10.1016/j.chempr.2021.07.005
日期:2021.8
frequently found in pharmaceutical compounds. To date, there is no strategy for synthesizing N-trifluoromethyl amides from abundant organic carboxylicacid derivatives, which are ideal starting materials in amide synthesis. Here, we report the synthesis of N-trifluoromethyl amides fromcarboxylicacid halides and esters under mild conditions via isothiocyanates in the presence of silver fluoride at room temperature
Pyroglutamic acid as a pseudoproline moiety: a facile method for its introduction into polypeptide chains
作者:Claudia Tomasini、Marzia Villa
DOI:10.1016/s0040-4039(01)00981-9
日期:2001.7
The acylation of benzyl (S)-pyroglutamate is reported by reaction with the pentafluorophenyl ester of protected alanine and threonine. The H-1 NMR analysis of the acylated products shows that the alpha hydrogens of the protected amino acids are very deshielded. This effect is due to the presence of the carbonyl of the lactam ring and shows that the peptide bond is in the trans conformation. The deprotection of the amino acids is also reported. (C) 2001 Elsevier Science Ltd. All rights reserved.