Mehravar Maryam, Mirjalili Bi Bi Fatemeh, Babaei Elaheh, Bamoniri Abdolhamid
Department of Chemistry, College of Science, Yazd University, Yazd, Iran.
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Iran.
BMC Chem. 2021 May 21;15(1):34. doi: 10.1186/s13065-021-00760-3.
The nano-sized particles enhance the exposed surface area of the active part of the catalyst, thereby increasing the contact between precursors and catalyst considerably. In this study, nano-SiO/1,5-diazabicyclo[4.3.0]non-5-en was synthesized, characterized and used as a heterogeneous nanocatalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives. Fourier Transform Infrared Spectroscopy, Field Emission Scanning Electron Microscopy, Brunauer-Emmett-Teller plot, Energy Dispersive X-ray Spectroscopy and Thermo Gravimetric Analysis were used to discern nano-SiO/1,5-diazabicyclo[4.3.0]non-5-en.
Tetrahydrobenzo[b]pyrans were synthesized by using nano-SiO/1,5-diazabicyclo[4.3.0]non-5-en via one-pot three-component condensation of malononitrile, aldehydes and dimedone in HO/EtOH at 60 °C. The results indicate that tetrahydrobenzo[b]pyrans were synthesized in good to high yields and short reaction times.
The fundamental privileges of this method are short reaction time, plain procedure, recyclability of catalyst and high yields of products.
纳米级颗粒增加了催化剂活性部分的暴露表面积，从而显著增加了前体与催化剂之间的接触。在本研究中，合成了纳米二氧化硅/1,5-二氮杂双环[4.3.0]壬-5-烯，对其进行了表征，并将其用作合成四氢苯并[b]吡喃衍生物的多相纳米催化剂。采用傅里叶变换红外光谱、场发射扫描电子显微镜、布鲁诺尔-埃米特-泰勒图、能量色散X射线光谱和热重分析来鉴别纳米二氧化硅/1,5-二氮杂双环[4.3.0]壬-5-烯。
通过纳米二氧化硅/1,5-二氮杂双环[4.3.0]壬-5-烯，在60℃下于水/乙醇中通过丙二腈、醛和二氢嘧啶的一锅三组分缩合反应合成了四氢苯并[b]吡喃。结果表明，四氢苯并[b]吡喃的合成产率良好至高，且反应时间短。
该方法的主要优点是反应时间短、步骤简单、催化剂可回收且产物产率高。
