Silica-supported NiO nanocomposites prepared via a sol–gel technique and their excellent catalytic performance for one-pot multicomponent synthesis of benzodiazepine derivatives under microwave irradiation
Heterogeneous and versatile NiO–SiO2 NCs were synthesized by a sol–gel technique and used as a catalyst for the one-pot multicomponent synthesis of benzodiazepine derivatives (4a–u) from a mixture of o-phenylenediamine, aromatic aldehydes and dimedone undermicrowaveirradiation. Tetraethyl orthosilicate (TEOS) was used as a source of SiO2 for the creation of the NiO–SiO2 NCs. This catalytic protocol
通过溶胶-凝胶技术合成了多相且用途广泛的NiO-SiO 2 NCs,并用作微波催化邻苯二胺,芳族醛和二甲基酮的混合物单锅多组分合成苯二氮卓衍生物(4a-u)的催化剂辐射。原硅酸四乙酯(TEOS)被用作SiO 2的来源,用于产生NiO–SiO 2NCs。该催化方案具有许多优点,例如后处理简单,廉价的前体,短的反应时间,高产率和高表面积。通过元素分析,扫描电子显微镜(SEM),透射电子显微镜(TEM),X射线衍射(XRD),能量色散X射线光谱(EDAX)和傅里叶变换表征了所制备纳米催化剂的结构和形貌。红外(FTIR)光谱。进行1 H NMR,13 C NMR和MS分析以确认合成的化合物(4a–u)。此外,NiO-SiO 2 NCs出色的催化性能使催化剂易于从反应混合物中分离出来,而不会明显降低催化活性。
Design, preparation and characterization of Cu/GA/Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>nanoparticles as a catalyst for the synthesis of benzodiazepines and imidazoles
The synthesis and characterization of an efficient and reusable nanocatalyst, Cu/GA/Fe3O4@SiO2, obtained by ultrasonic‐assisted grafting of guanidineacetic acid on modified Fe3O4@SiO2 core–shell nanocomposite spheres and subsequent immobilization of Cu(II), are described. The catalyst was characterized by means of X‐ray diffraction, scanning and transmission electron microscopies, energy‐dispersive
An efficient, environmentally benign, and solvent-free protocol for the synthesis of 4-substituted 1,5-benzodiazepines catalyzed by reusable sulfated polyborate
作者:Krishna S. Indalkar、Manisha S. Patil、Ganesh U. Chaturbhuj
DOI:10.1016/j.tetlet.2017.10.030
日期:2017.11
developed for the one-pot solvent-free synthesis of 4-substituted-1,5-benzodiazepines via three-component reaction of o-phenylenediamine, dimedone with a variety of aldehydes catalyzed by sulfated polyborate. The major advantages of the present method are good to excellent yields, shorter reaction time, simple experimental procedure, easy workup, solvent-free reaction condition, recyclability of the