In 2013,El-Gendy, Bahaa El-Dien M.; Zadeh, Ebrahim H. Ghazvini; Sotuyo, Ania C.; Pillai, Girinath G.; Katritzky, Alan R. published 《α-substitution effects on the ease of S → N-acyl transfer in aminothioesters》.Chemical Biology & Drug Design published the findings.Product Details of 139115-91-6 The information in the text is summarized as follows:
The present work investigates the ease of ligations in compounds with all carbon/oxygen (but no amidic group) backbones as compared with those found in peptide sequences with 5-, 6-, and 8-membered cyclic TSs, aiming initially to examine the differential effect of cysteine-free acid, α-ester, and α-amide groups on transition state conformation during the ligation process. In S-acylcysteines and homocysteines the efficacy and rate of S → N-acyl transfer (5 and 6 cyclic TSs) vary with the size of S-acyl group. Conformational and quantum chem. calculations indicate that the spatial distance, b(N-C), between the terminal amine and the thioester carbon is shortened by α-C(O)X (X = OH, OMe, NH2) substituents. The experimental part of the paper was very detailed, including the reaction process of tert-Butyl (2-(2-hydroxyethoxy)ethyl)carbamate(cas: 139115-91-6Product Details of 139115-91-6)
tert-Butyl (2-(2-hydroxyethoxy)ethyl)carbamate(cas: 139115-91-6) belongs to ethers.The C-O bonds that comprise simple ethers are strong. They are unreactive toward all but the strongest bases. Although generally of low chemical reactivity, they are more reactive than alkanes. Product Details of 139115-91-6
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem