A catalytic reaction comprises several steps: providing a catalyst, wherein the catalyst is metal or metal oxide particles and at least have 110} crystal plane; using the catalyst when performing a cycloaddition reaction. By using the catalyst with high reactivity, reaction rate is dramatically promoted.
One-pot regioselective synthesis of substituted pyrazoles and isoxazoles in PEG-400/water medium by Cu-free nano-Pd catalyzed sequential acyl Sonogashira coupling–intramolecular cyclization
Catalyst efficacy of in situ generated Pd-nanoparticles (PdNPs) in the regioselective one-pot synthesis of 3,5-di & 3,4,5-trisubstituted pyrazoles and 3,5-disubstituted isoxazoles in environmentally benign PEG-400/H2O medium, which involves the sequential (i) Cu-free acyl-Sonogashira coupling (ASC) and (ii) intramolecular ynone–amine cyclization under PTC conditions was described. The results of controlled
在环境友好的PEG-400 / H 2中原位生成的Pd-纳米颗粒(PdNPs)在区域选择性一锅合成3,5-di和3,4,5-三取代的吡唑和3,5-二取代的异恶唑的催化剂效力描述了一种O介质,它涉及(i)在PTC条件下无Cu的酰基-Sonogashira偶联(ASC)和(ii)分子内的ynone-amine环化。受控实验的结果支持两个连续的催化循环(ASC /环化)的操作,并通过一锅法通过与炔酮结合的钯实现互补/相反的区域选择性。而且,就地一锅法反应序列的第一个催化循环后回收的PdNPs已连续五次再次使用。此外,在进行上述研究之前,某些常见的Pd-N-杂环卡宾(Pd-NHC)配合物在水和有机物中催化相同的一锅两步反应顺序(无铜ASC /环化)的功效还优化了溶剂。还可以从水中的Pd-NHC上方原位生成PdNP,但由于它们的尺寸较大,因此无法重复使用。
Trichloroisocyanuric acid mediated one-pot synthesis of 3,5-diarylisoxazoles from <i>α,β</i>-unsaturated ketones
作者:Ashish Bhatt、Rajesh K. Singh、Ravi Kant
DOI:10.1080/00397911.2019.1590848
日期:2019.4.18
Abstract A facile one-pot synthesis of 3,5-diarylisoxazoles from α,β-unsaturatedketones and hydroxylamine hydrochloride is reported. The reaction is efficiently promoted by trichloroisocyanuric acid (TCCA) to afford the desired products, mostly in high yields and in relatively short time. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This
A convenient one-pot synthesis of 3,5-diarylisoxazoles via oxidative cyclisation using catalytic CuBr2 and oxone
作者:Ashish Bhatt、Rajesh K. Singh、Ravi Kant
DOI:10.1016/j.tetlet.2019.03.044
日期:2019.4
A facile one-pot synthesis of 3,5-diarylisoxazoles from α,β-unsaturated ketones and hydroxylamine hydrochloride is reported. The reaction is efficiently promoted by catalytic CuBr2 and Oxone to afford the desired products mostly in high yields and in relatively short time. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This protocol is effective
A general access to isoxazoles with outstanding functional group compatibility from the readily available ynones using trimethylsilyl azide as an amino surrogate under exceptionally simple conditions is described.