[3 + 2]-Cycloaddition of <i>in Situ</i> Generated Nitrile Imines and Acetylene for Assembling of 1,3-Disubstituted Pyrazoles with Quantitative Deuterium Labeling
作者:Vladimir V. Voronin、Maria S. Ledovskaya、Evgeniy G. Gordeev、Konstantin S. Rodygin、Valentine P. Ananikov
DOI:10.1021/acs.joc.8b00155
日期:2018.4.6
methodology for the preparation of 1,3-disubstituted pyrazoles from in situ generated nitrile imines and acetylene is reported. The reactions are performed in a simple two-chamber reactor. One part of the reactor is loaded with hydrazonoyl chloride precursors of active nitrile imine species and a base. The other part is used to generate acetylene from CaC2 and water. Partitioning of the reactants improves
报道了一种从原位生成的腈亚胺和乙炔制备1,3-二取代吡唑的新型合成方法。反应在简单的两室反应器中进行。反应器的一部分装有活性腈亚胺物种的酰氯前体和碱。另一部分用于从CaC 2生成乙炔和水。反应物的分配将所需的吡唑的产率提高至高达99%,并简化了其通过简单的溶剂蒸发步骤的分离。该方法不需要复杂的设备,并利用廉价,安全且易于处理的电石作为起始原料。根据开发的方法进行模型氘掺入,产生了一系列具有优异氘富集的新型4,5-二氢杂萘并恶唑。对反应机理进行了理论计算,并对可能的中间结构进行了表征。