Direct modification of tripeptides using photoinduced decarboxylative radical reactions
作者:Kousuke Maeda、Hikaru Saito、Kazuyuki Osaka、Keisuke Nishikawa、Mai Sugie、Toshio Morita、Ichiro Takahashi、Yasuharu Yoshimi
DOI:10.1016/j.tet.2014.12.075
日期:2015.2
In order to explore the applicability of photoinduced electron transfer (PET) promoted decarboxylative reactions to the direct modification of peptides, a study was performed to assess the influence of amino acid side chains on photoreactions of N-terminal protected tripeptides. Photoinduced decarboxylation reactions of tripeptides, which are composed of central amino acids that possess alkyl, phenyl, thioether, hydroxy, and amide containing side chains, in the presence or absence of acrylonitrile and a thiol were found to proceed smoothly to give the corresponding radical addition, H-abstraction, and substitution products. Although photoreactions of tripeptides containing central amino acids with phenol and indole (Tyr and Trp) moieties do not take place efficiently, appropriate protection of these groups enables the substrates to undergo smooth photoinduced decarboxylative reactions. (C) 2014 Elsevier Ltd. All rights reserved.