We report herein an efficient protocol for the synthesis of N-urethane-protected α-amino/peptide thioacids from their corresponding acids mediated by EDC and Na2S. The fast reaction under mild conditions enabled the process to be completed in shorter duration with good yield circumventing column purification. The chemistry is compatible with a wide variety of urethane protecting groups, side-chain functionalities, and sterically hindered amino acids.
Rhodium-catalyzed regioselective addition of thioacids to terminal allenes: enantioselective access to branched allylic thioesters
作者:A. Ziyaei Halimehjani、B. Breit
DOI:10.1039/d1cc06470c
日期:——
Rhodium-catalyzed regio- and enantioselective hydrothiolation of terminal allenes with thioacids is reported for the atom-economic synthesis of chiral branched allylic thioesters. By using a rhodium(I) catalyst system, diversities of terminal allenes and thioacids afforded the corresponding branched thioesters in excellent regioselectivity, high yield, and good enantioselectivity. This method was also explored
据报道,在手性支链烯丙基硫酯的原子经济合成中,铑催化的末端丙二烯与硫代酸的区域选择性和对映选择性氢硫醇化反应。通过使用铑( I )催化剂体系,末端丙二烯和硫代酸的多样性提供了相应的支链硫酯,具有优异的区域选择性、高收率和良好的对映选择性。该方法还探索了 Fmoc 保护的氨基硫代酸,用于非对映选择性合成相应的硫酯。
Amidine Functionality As a Conformational Probe of Cyclic Peptides
作者:Sungjoon Huh、Solomon D. Appavoo、Andrei K. Yudin
DOI:10.1021/acs.orglett.0c03369
日期:2020.12.4
The amidine functionality switches between hydrogen bond donor and acceptor roles depending on pH. Herein, the amidine was incorporated to select amides in cyclo(d-Ala-Pro-d-Phe-Pro-Gly). The unprotonated amidine-containing macrocyclic conformation resembles its oxoamide counterpart. Upon protonation, minimal alterations in the macrocyclic conformation were observed despite changes to the hydrogen
脒官能团根据 pH 在氢键供体和受体角色之间切换。在本文中,脒被掺入以选择环(d -Ala -Pro- d -Phe-Pro-Gly)中的酰胺。未质子化的含脒大环构象类似于其氧代酰胺对应物。质子化后,尽管氢键网络发生了变化,但观察到大环构象的变化很小。脒以最小的空间成本破坏氢键,使其成为研究氢键对大环构象影响的有用功能。