为了开发非基于嘌呤的黄嘌呤氧化酶 (XO) 抑制剂,考虑到使用基于嘌呤的 XO 抑制剂报告的并发症,黄酮框架(一类具有 XO 抑制潜力)被用作先导结构进一步优化。由于喹诺酮类的生物活性潜力和类药物特性,通过基于结构的经典生物等排体,喹诺酮被用作色酮(黄酮中的双环单元)的等排体。这种类型的置换不会改变 XO 抑制所需的形状和结构特征,还提供了一些额外的相互作用位点,而不会丢失氢键和疏水性和芳烃-芳烃相互作用。在本研究中,合理设计了一系列 2-芳基/杂芳基-4-喹诺酮类(黄酮的氮杂类似物),合成并评估体外 XO 抑制活性。提出了一些关于结构-活性关系的概念,表明 2-芳环的性质对抑制活性的影响。最活跃的化合物 3l (IC50 = 6.24 µM) 与 XO 活性位点的氨基酸残基之间的重要相互作用是通过分子模型计算出来的。
Bifunctional catalysts bearing two catalytic sites, Lewis acidic organometallic titanocene and Brønsted acidic COOH, have been assembled in situ from Cp2TiCl2 with carboxylic acid ligands, showing high catalytic activity over an intramolecular Mannich reaction towards synthesis of 2‐aryl‐2,3‐dihydroquinolin‐4(1H)‐ones. The determination of the bifunctional catalyst Cp2Ti(C8H4NO6)2 was elucidated by
具有羧酸催化配体的Cp 2 TiCl 2原位组装了带有两个催化位点的Lewis酸性有机金属钛茂和Brønsted酸性COOH双功能催化剂,在分子内曼尼希反应中对2-芳基-2,3的合成显示出高催化活性。 -dihydroquinolin-4(1H)-1。双功能催化剂Cp 2 Ti(C 8 H 4 NO 6)2的测定单个X射线HRMS和催化行为的研究阐明了这一点。特别是,用休眠的COOMe掩盖布朗斯台德酸性COOH催化位点会大大降低反应产率,这表明两个催化位点共同作用以保持高催化效率。
Lithium tetrafluoroborate catalyzed highly efficient inter- and intramolecular aza-Michael addition with aromatic amines
Abstract Lithium tetrafluoroborate has been demonstrated for the first time to be an efficient catalyst in intermolecular aza-Michael addition aromatic amines to electron deficient alkenes. Suitability of the same catalyst in intramolecular aza-Michael addition leading 2-aryl-2,3-dihydroquinolin-4(1H) ones has also been described.
Eco-friendly polyethylene glycol promoted Michael addition reactions of α,β-unsaturated carbonyl compounds
作者:Dalip Kumar、Gautam Patel、Braja G. Mishra、Rajender S. Varma
DOI:10.1016/j.tetlet.2008.09.116
日期:2008.12
Intra- and inter-nucleophilic addition reactions of different α,β-unsaturatedcarbonylcompounds were found to be highly effective without any additives in PEG-400 as a recyclable reaction medium under neutral conditions.
Ytterbium(III) triflate: An efficient and simple catalyst for isomerization of 2′-hydroxychalcone and 2′-aminochalcones in ionic liquid
作者:V. Kameswara Rao、M. Sudershan Rao、Anil Kumar
DOI:10.1002/jhet.760
日期:2011.11
Isomerization of 2′‐hydroxychalcone and 2′‐aminochalcone have been investigated using ytterbium(III) trifluromethanesulfonate Yb(OTf)3} (30 mol %) as Lewis acid catalyst in [bmim][BF4] ionicliquid. The effect of different metal triflates as Lewis acid, catalyst loading and reaction media was studied for this isomerization reaction. Advantages of the methodology include short reaction time, excellent
Palladium-catalyzed heteroannulation with acetylenic carbinols as synthons-synthesis of quinolines and 2,3-dihydro-4(1H)-quinolones
作者:Jyan S Mahanty、Mahuya De、Palas Das、Nitya G Kundu
DOI:10.1016/s0040-4020(97)00852-1
日期:1997.9
quinolines 2. An excellent synthesis of the alkaloid dubamine (2n) is reported. Also, the anilides 6 on acid-catalyzed rearrangement, deprotection and cyclisation led to the 2-aryl-2, 3-dihydro-4(1H)-quinolones 16.