NH–π and CH–π interactions, due to their weak character, are not easily identified in solution. We report a group of isolable shortpeptides with stable folds, in which NH–π and CH–π main chain–side chain interactions can be detected in solution by means of NMR and ATR-IR spectroscopy.
Generation of shortpeptides with a single β-strand structure in solution is difficult. Herein, we design a new class of single β-strand peptidic mimics that are stable without self-aggregation in protic and non-protic solvents. Introduction of one present β-strand mimic can induce and propagate the β-strand structure for at least a penta-peptide sequence.
Acetylation Under Ultrasonic Conditions: Convenient Preparation of N-Acetylamino Acids
作者:A. Veera Reddy、B. Ravindranath
DOI:10.1080/00397919208021300
日期:1992.1
An efficient and simple method of preparation of acetylamino acids from amino acids under ultrasonic conditions is described. The reactions proceed without racemization and the yields are almost quantitative.
Development of an Asymmetric Hydrogenation Route to (<i>S</i>)-<i>N</i>-Boc-2,6-dimethyltyrosine
作者:Céline F. B. Praquin、Pieter D. de Koning、Philip J. Peach、Roger M. Howard、Sarah L. Spencer
DOI:10.1021/op200065p
日期:2011.9.16
An improved, simpler and potentially more economical route to (S)-N-Boc-2,6-dimethyltyrosine 1, based on a previously published route, is presented. Key modifications were to prepare the dehydroaminoacid hydrogenation substrate 6 in a one-pot process directly from serine methyl ester and 4-iodo-3,5-dimethylphenyl acetate 4 and to identify a significantly more active asymmetric hydrogenation catalyst that allowed a 5-fold reduction in catalyst loading.
Rothstein, Journal of the Chemical Society, 1949, p. 1970