The tautomerism of heteroaromatic compounds with 5-membered rings—XI
作者:G. Bianchi、M.J. Cook、A.R. Katritzky
DOI:10.1016/s0040-4020(01)91778-8
日期:1971.1
Four 4-hydroxyisoxazoles together with model compounds have been investigated by UV, IR and NMR spectroscopy and by pKa measurements, 4-Hydroxyisoxazoles exist predominantly in the hydroxy-form in a wide range of media.
通过紫外,红外和核磁共振光谱研究了四种4-羟基异恶唑和模型化合物,通过p K a测量,4-羟基异恶唑主要以羟基形式存在于多种介质中。
Asymmetric Retro-Claisen Reaction by Synergistic Chiral Primary Amine/Palladium Catalysis
作者:Yanfang Han、Long Zhang、Sanzhong Luo
DOI:10.1021/acs.orglett.9b02491
日期:2019.9.20
We described herein a chiral primaryamine/palladium catalyzed asymmetric retro-Claisen reaction of β-diketones with salicylic carbonates. A series of chiral α-alkylated ketones and macrolides were obtained with good yields and excellent enantioselectivities upon a sequence of decarboxylative benzylation, retro-Claisen cleavage, and enamine protonation. This strategy features broad substrate scope
[EN] SUBSTITUTED 6-(1H-PYRAZOL-1-YL)PYRIMIDIN-4-AMINE DERIVATIVES AND USES THEREOF<br/>[FR] DÉRIVÉS DE 6- (1H-PYRAZOL-1-YL) PYRIMIDIN-4-AMINE SUBSTITUÉS ET LEURS UTILISATIONS
申请人:BAYER AG
公开号:WO2018069222A1
公开(公告)日:2018-04-19
The present invention covers substituted 6-(1H-pyrazol-1-yl)pyrimidin-4-amine compounds of general formula (I) as described and defined herein, methods of preparing said compounds, intermediate compounds useful for preparing said compounds, pharmaceutical compositions and combinations comprising said compounds, and the use of said compounds for manufacturing pharmaceutical compositions for the treatment or prophylaxis of diseases, in particular for the treatment and/or prophylaxis of cardiovascular and renal diseases, as a sole agent or in combination with other active ingredients.
The Effect of Ring Nitrogen Atoms on the Homolytic Reactivity of Phenolic Compounds: Understanding the Radical-Scavenging Ability of 5-Pyrimidinols
作者:Luca Valgimigli、Giovanni Brigati、Gian Franco Pedulli、Gino A. DiLabio、Marina Mastragostino、Catia Arbizzani、Derek A. Pratt
DOI:10.1002/chem.200304960
日期:2003.10.17
BDEs, 5-pyrimidinols appear to transfer their phenolichydrogen-atom to peroxyl radicals as quickly as equivalently substituted phenols, while their reactivity toward alkyl radicals far exceeds that of the corresponding phenols. We suggest that this rate enhancement, which is large in the case of alkyl radical reactions, small in the case of peroxyl radical reactions, and nonexistent in the case of
合成了六个取代的5-嘧啶醇,研究了它们与自由基反应的热化学和动力学,并将其与同等取代的酚进行了比较。为了评估其作为自由基的氢原子供体的潜力,我们使用自由基平衡电子顺磁共振技术测量了其OH键离解焓(BDE)。这表明,5-嘧啶醇中的OH BDE平均比同等取代的酚类中的高约2.5 kcal mol(-1)。结果与理论预测吻合良好,证实了取代基对5-嘧啶醇的OH BDE的影响与对苯酚中Obond; H BDE的影响基本相同。通过抑制AIBN引发的苯乙烯的自氧化,以及通过竞争动力学与烷基和烷氧基的反应,研究了这些化合物与过氧自由基的反应动力学。尽管它们的OH BDE较大,但5-嘧啶醇似乎将其酚氢原子转移到过氧自由基上的速度与同等取代的酚一样快,而它们对烷基自由基的反应性却远远超过了相应的酚。我们建议,这种速率的提高是由于这些原子的过渡态中的极性效应引起的,该速率的提高在烷基自由基反应的情况下较大,在
Synthesis of Valuable Chiral Intermediates by Isolated Ketoreductases: Application in the Synthesis of α-Alkyl-β-hydroxy Ketones and 1,3-Diols
作者:Dimitris Kalaitzakis、J. David Rozzell、Ioulia Smonou、Spiros Kambourakis
DOI:10.1002/adsc.200606185
日期:2006.9
and in two examples both ketones were reduced to the 1,3-diol. By replacing the α-alkyl substituent with the OAc group, 1-keto-2,3-diols, as well as 1,2,3-triols were synthesized in high optical purities. These enzymatic reactions provide a simple, highly stereoselective and quantitative method for the synthesis of different diastereomers of valuable chiralsynthonsfrom non-chiral, easily accessible