α-Methyl phenylglycines by asymmetric α-arylation of alanine and their effect on the conformational preference of helical Aib foldamers
作者:Romain Costil、Fernando Fernández-Nieto、Rachel C. Atkinson、Jonathan Clayden
DOI:10.1039/c8ob00551f
日期:——
α-Arylated alanine derivatives were made enantioselectively by migratory rearrangement of a urea derivative using (R,R)-pseudoephedrine as a chiral auxiliary. Incorporation of a single residue of the product α-methyl phenylglycine into an otherwise achiral oligomer of aminoisobutyric acid oligomer induced a preferred screw sense, detectable by a NMR reporter located at the remote terminus of the oligomer
α-芳基化丙氨酸衍生物是通过使用 ( R , R )-伪麻黄碱作为手性助剂对脲衍生物进行迁移重排来进行对映选择性制备的。将产物α-甲基苯基甘氨酸的单个残基掺入到氨基异丁酸低聚物的其他非手性低聚物中诱导了优选的螺旋感觉,可通过位于低聚物远端的NMR报告子检测到。当手性残基位于折叠体的 N 末端时,螺旋感诱导的幅度更大,并且在某些情况下,诱导感与具有除芳基以外的 α-取代基的相关 α-甲基化氨基酸的诱导感相反.
Quantifying End-to-End Conformational Communication of Chirality through an Achiral Peptide Chain
作者:Jonathan Clayden、Alejandro Castellanos、Jordi Solà、Gareth A. Morris
DOI:10.1002/anie.200901892
日期:2009.7.27
Successful communication: Two diastereotopic protons more than 60 bonds from the nearest chiral center appear as an AB system, showing that the intervening structure is a well‐ordered helix. Decay of anisochronicity quantifies the linear persistence of a helix of achiral amino acids: as little as 3.5 % of the chiral influence is lost with each additional achiral residue.
Nanometer-Range Communication of Stereochemical Information by Reversible Switching of Molecular Helicity
作者:Jordi Solà、Stephen P. Fletcher、Alejandro Castellanos、Jonathan Clayden
DOI:10.1002/anie.201001130
日期:2010.9.10
A long‐distance call: The inversion of configuration at a stereogenic center led to a detectable switch in the position of a 13C stereochemical probe 40 bonds (2.5 nm) away. Information was relayed between the sites by an inversion of screwsense in the intervening helix as illustrated (13C NMR signals were read as output).
长途电话:立体定向中心的构型反转导致距离40个键(2.5 nm)的13 C立体化学探针的位置出现可检测的开关。如图所示,通过插入螺旋之间的螺旋方向反转,信息在位点之间传递(将13 C NMR信号读取为输出)。