Five compounds bearing electron-deficient pentafluorophenyl as well as electron-rich (salicylate or indole) aromatic moieties connected by amide or ester linkages were investigated by X-ray diffraction. In the crystals, various interactions (π–π, lone pair–π) between the different aromatic units are important structure controlling factors in addition to the stronger inter- or intramolecular hydrogen
通过 X 射线衍射研究了五种带有缺电子五氟苯基以及通过酰胺或酯键连接的富电子(水杨酸酯或吲哚)芳族部分的化合物。在晶体中,除了酰胺和酯部分诱导的更强的分子间或分子内氢键之外,不同芳香单元之间的各种相互作用(π-π,孤对-π)是重要的结构控制因素。氢键导致分子结构单元的聚合和大环组装。
Site-Selective Polyfluoroaryl Modification and Unsymmetric Stapling of Unprotected Peptides
Peptide stapling is recognized as an effective strategy for improving the proteolytic stability and cell permeability of peptides. In this study, we present a novel approach for the site-selective unsymmetric perfluoroaryl stapling of Ser and Cys residues in unprotected peptides. The stapling reaction proceeds smoothly under very mild conditions, exhibiting a remarkably rapid reaction rate. It can
肽装订被认为是提高肽的蛋白水解稳定性和细胞通透性的有效策略。在这项研究中,我们提出了一种新方法,用于对未受保护的肽中的 Ser 和 Cys 残基进行位点选择性不对称全氟芳基装订。装订反应在非常温和的条件下顺利进行,表现出非常快的反应速率。它可以提供液相和固相的固定产物,并且肽中除 Cys 硫醇以外的亲核基团的存在不会阻碍反应,从而获得一致的高产率。重要的是,Ser β-C(sp 3 )–H 的化学选择性激活使未反应的 -OH 能够作为反应手柄,用于随后对具有各种治疗功能的主链部分进行不同的修饰,包括可点击的叠氮基、极性部分、脂质标签和荧光染料。在我们的研究中,我们还开发了可见光诱导的 Ser β 位化学选择性 C(sp 3 )–H 多氟芳基化。该反应避免了对 Ser -OH 竞争反应的干扰,从而能够对含有其他高反应性氨基酸残基的各种未受保护的肽中的 Ser 残基进行精确的后期多氟芳基化修饰
Transformation of Contact-Explosives Primary Amines and Iodine(III) into a Successful Chemical Reaction under Solvent-Free Ball Milling Conditions
作者:Tapas Kumar Achar、Prasenjit Mal
DOI:10.1002/adsc.201500914
日期:2015.12.14
Any synthetic transformation using contact-explosivesprimaryamines and hypervalent iodine(III) (phenyliodine diacetate) in constrained media (extreme conditions) is practically impossible. Herein, we report a method of controlling the explosion into a successfulchemicalreaction using the acid-salt NaHSO4. As a proof-of-concept, we considered mechanochemical (ball-milling) cross dehydrogenative
that the reaction occurred through Lewis acid-promoted HAT to provide an alkyl radical and sequential addition to polyfluoroarenes. Impressively, the regioselectivity for C–F cleavage was verified with the Fukui function. The feasibility and application of this protocol on fluoroarene synthesis were well illustrated by gram-scale synthesisunder both batch and flow conditions, late-stage decoration of