Iron-catalyzed aerobic oxidative aromatization of 1,3,5-trisubstituted pyrazolines
作者:Guddekoppa S. Ananthnag、Adithya Adhikari、Maravanji S. Balakrishna
DOI:10.1016/j.catcom.2013.09.002
日期:2014.1
A simple and high yielding method for the synthesis of tri-substituted pyrazoles via iron(III) catalyzed aerobic oxidative aromatization of pyrazolines has been reported. The process demonstrates a variety of functional group tolerance.
Nanorod vanadatesulfuric acid (VSA NRs), as a recyclable and ecologically benign catalyst, was used for the one‐pot synthesis of chalcones and 1,3,5‐triaryl‐2‐pyrazolines (TAPs). Chalcones were prepared via the condensation of substituted acetophenones with aryl‐aldehydes under solvent‐free conditions. Subsequently, the synthesized chalcones were used for the catalytic synthesis of TAPs via two‐component
Mechanically activated synthesis of 1,3,5-triaryl-2-pyrazolines by high speed ball milling
作者:Xingyi Zhu、Zhenhua Li、Can Jin、Li Xu、Qianqian Wu、Weike Su
DOI:10.1039/b816788e
日期:——
An efficient mechanicallyactivated solvent-free synthesis of 1,3,5-triaryl-2-pyrazolines from chalcones and phenylhydrazines using high speed ballmilling is described. This method has notable advantages in terms of good yield, short reaction time and neat conditions.
possible intermediate carbocations. The synthetic utility of a green solvent has been explored by synthesizing some of pyrazolines in a DES medium. The synthetic application of the present methodology is employed in the synthesis of a pyrazoline alkaloid.
TfOH 介导容易获得从醛、苯肼和苯乙烯开始的有趣的吡唑啉。通过以非常高的收率和非常高的区域选择性合成各种 1,3,5-三取代的吡唑啉,探索了这种合成方法的范围。通过比较可能的中间碳阳离子的稳定性来解释区域选择性的起源。通过在 DES 介质中合成一些吡唑啉,探索了绿色溶剂的合成效用。本方法的合成应用用于吡唑啉生物碱的合成。
Photooxidation of 3,5-diaryl-1-phenyl-2-pyrazolines: Experimental and computational studies
Photooxidation of various 2-pyrazolines is studied experimentally and computationally. Experimental results show that the electron-donating/withdrawing substituents increases/decreases the rate of this photoreaction. The proposed light-induced electron-transfer mechanism explains the steric and electronic effects of the substituents, co-planarity of the aryl rings substitutions, orientations of the
实验和计算研究了各种2-吡唑啉的光氧化作用。实验结果表明,给电子/吸电子取代基增加/降低了这种光反应的速率。拟议的光诱导电子转移机理解释了取代基的空间和电子效应,芳基环取代基的共面性,C 3-芳基环向C 3 = N 2的方向双键与溶剂在照射时间上反应完全。计算(TD)B3LYP / 6-311 ++ G(d,p)结果,包括前沿轨道能量,UV-可见跃迁,静电势,CHELPG电荷,用于发现和描述隧道电子转移过程及其相关结构弛豫形成反应的速率决定步骤,并证明取代对反应速率的影响是正确的。第一次电子转移后形成的中间体络合物仅在其三重态下才进行质子转移步骤。2-吡唑啉的三重态激发态可能对电子转移步骤几乎没有贡献。循环伏安法测量结果支持了光化学结果。