Simple and efficient protocol for synthesis of pyrido[1,2-a]pyrimidin-4-one derivatives over solid heteropolyacid catalysts
作者:Sulaiman N. Basahel、Nesreen S. Ahmed、Katabathini Narasimharao、Mohamed Mokhtar
DOI:10.1039/c5ra22180c
日期:——
of surface area and Lewis acid sites was observed with increase of Al content. The catalysts have been applied as heterogeneous catalysts to synthesize pyrido[1,2-a]pyrimidines under mild reaction conditions. A variety of biologically active pyrido[1,2-a]pyrimidines were obtained in best yields ever (above 90%) by using a simple, eco-friendly and efficient protocol catalyzed by AlxH3−xPW12O40 catalysts
采用简单的离子交换法制备了具有Keggin结构的铝交换钨磷酸盐(Al x H 3− x PW 12 O 40)。通过各种技术,如元素分析,XRD,FTIR,UV-vis,N 2-物理吸附,NH 3 -TPD和FTIR-吡啶吸附,对制备的杂多酸盐进行了表征。所有制备的催化剂都具有布朗斯台德和路易斯酸位点,但是随着铝含量的增加,表面积和路易斯酸位点增加。该催化剂已被用作非均相催化剂,以在温和的反应条件下合成吡啶并[1,2- a ]嘧啶。多种具有生物活性的吡啶基[1,2-通过使用由Al x H 3− x PW 12 O 40催化剂催化的简单,环保和高效的方法,可以以最高的收率(90%以上)获得a ]嘧啶。Al 3 PW 12 O 40催化剂显示出最高的活性,这是由于通过Al 3+离子完全交换H +离子将更多的路易斯酸位引入母体H 3 PW 12 O 40。
Catalyst‐ and Oxidant‐Free Electrochemical Regioselective Halogenation and Trifluoromethylation of 4<i>H</i>‐Pyrido[1,2‐<i>a</i>]pyrimidin‐4‐ones
作者:Meiyun Su、Lina Guo、Peiyu Mao、Meng Xiao、Wenjie Liu、Shaohua Wang
DOI:10.1002/ejoc.202300268
日期:2023.8
halogenation and trifluoromethylation of 4H-pyrido[1,2-a]pyrimidin-4-ones with cheap and commercially available sodium salts have been developed under external oxidant-free conditions. The reaction shows broad scope of substrates, high regioselectivity, and good functional group compatibility. Importantly, the electrosynthesis of 4H-pyrido[1,2-a]pyrimidin-4-ones represents a green and advantageous alternative
已开发出在无外部氧化剂的条件下用廉价且市售的钠盐进行 4 H-吡啶并[1,2- a ]嘧啶-4-酮的无催化剂电化学卤化和三氟甲基化。该反应显示出底物范围广、区域选择性高、官能团相容性好。重要的是,4 H-吡啶并[1,2- a ]嘧啶-4-酮的电合成代表了传统合成方法的绿色且有利的替代方法。