α -氨基酸衍生的苯并咪唑联罗丹明已被合成,和它们的金属离子传感特性进行了评价。实验上,衍生自1-缬氨酸和1-苯基甘氨酸的基于苯并咪唑的若丹明1和2可选择性识别CH 3 CN水溶液中的Al 3+离子(CH 3 CN / H 2 O 4/1 v / v,10 mM tris HCl缓冲液(pH 7.0),通过显示颜色和“开启”发射变化来实现。相反,甘氨酸衍生的苯并咪唑3在识别事件中保持沉默,并强调了氨基酸α-取代在设计中所起的作用。该事实已根据单晶X射线结构和理论计算得到解决。此外,粉1 ·的Al 3+和2 ·铝3+合奏选择性地感测˚F -通过颜色的放电过其它卤化物离子。重要的是,化合物1和2是可渗透细胞的,并且已用作成像试剂,用于检测人肺癌细胞系A549中的Al 3+摄取。
摘要 已经开发出一种简单的反应路线,该路线指向带有α-氨基酸和苯并[ d ]咪唑侧基的手性伯胺。在四个步骤的合成中,将六个起始必需α-氨基酸转化为目标手性胺。在4-硝基苯甲醛或靛红与丙酮或环己酮之间的直接不对称醛醇缩合反应中,将制备的胺筛选为有机催化剂。以良好的化学收率,高达97:3的非对映选择性(与环己酮的反应)和高达71%ee的对映选择性获得醛醇加合物。三氟乙酸和苯甲酸被证明是分别在4-硝基苯甲醛和靛红上进行羟醛合成的最佳助催化剂。 已经开发出一种简单的反应路线,该路线指向带有α-氨基酸和苯并[ d ]咪唑侧基的手性伯胺。在四个步骤的合成中,将六个起始必需α-氨基酸转化为目标手性胺。在4-硝基苯甲醛或靛红与丙酮或环己酮之间的直接不对称醛醇缩合反应中,将制备的胺筛选为有机催化剂。以良好的化学收率,高达97:3的非对映选择性(与环己酮的反应)和高达71%ee的对映选择性获得醛醇加合物。三氟
An efficient one-pot conversion of carboxylic acids into benzimidazoles <i>via</i> an HBTU-promoted methodology
作者:Leonard Barasa、Sabesan Yoganathan
DOI:10.1039/c8ra07773h
日期:——
Benzimidazole is a privileged, and routinely used pharmacophore in the drug discovery process. Herein, we report a mild, acid-free and one-potsynthesis of indole, alkyl and alpha-amino benzimidazoles through a novel HBTU-promoted methodology. An extensive library of indole-carboxylic acids, alkyl carboxylic acids and N-protected alpha-amino acids has been converted into the corresponding benzimidazoles
Benzo[d]imidazole and Aliphatic α-Amino Acid Derived Primary Amines in Asymmetric Aldol Reactions
作者:Filip Bureš、Pravinkumar Mohite、Pavel Drabina
DOI:10.1055/s-0033-1340598
日期:——
ted primaryamines were synthesized. The reaction sequence involves activation of the Boc-amino acid carboxylic acid, reaction with o -phenylenediamine, and subsequent cyclization to benzo[ d ]imidazole. N-Methylation and final Boc group removal afforded four new primaryamines. The synthesized amines were preliminarily applied as organocatalysts in an asymmetric version of the aldol reaction between
The synthesis of optically and diastereomerically pure P-stereogenic phosphine-imidazole ligands is reported. The new ligands contain either a benzoimidazole or a 4-phenylimidazole as a N-donor fragment. The ligands have been coordinated to iridium and the structure of the corresponding cationic COD complexes has been determined by X-ray analysis. The combination of the chiralphosphorus atom and the
<scp>l</scp>-Valine-derived simple benzimidazole-based host in selective sensing of Hg(II) ions
作者:Kumaresh Ghosh、Tanmay Sarkar
DOI:10.1080/10610278.2012.712696
日期:2012.10
A new and an easy-to-make simple benzimidazole-based chemosensor 1, derived from L-valine is reported. The chemosensor effectively recognises Hg2+ ion in the open cleft in CH3CN containing 0.2% DMSO by exhibiting significant enhancement in fluorescence emission. In the selectivity, the steric isopropyl groups in 1 play the key role as confirmed by considering the model compound 2. The ensemble of 1. Hg2+, on the other hand, shows the fluorescence sensing of L-cysteine, homocysteine, and glutathione over the other amino acids with no thiol group in aq. DMSO (DMSO:H2O 4:1, v/v).
l-Valine derived benzimidazole based bis-urea in enantioselective fluorescence sensing of L-tartrate
作者:Kumaresh Ghosh、Tanmay Sarkar
DOI:10.1016/j.tetlet.2013.06.087
日期:2013.8
L-Valine derived benzimidazole based bis-urea 1 has been designed and synthesized. The bis-urea 1 is found to act as enantioselective chemosensor for tartrate. The sensor shows greater fluorescence response for L-tartrate in DMSO. The enantiomeric fluorescence difference ratio (ef) has been determined to be 2.46. In comparison, less steric receptor 2 exhibits a marginal preference for D-tartrate over the L-tartrate in DMSO and validates the steric role of the substituents around the benzimidazole motif in 1 toward enantioselective recognition of tartrate. (C) 2013 Elsevier Ltd. All rights reserved.