چكيده به لاتين
bstract
The combination of multicomponent reactions with nanocatalysts has become a new and interesting subject of study, which will allow the simultaneous growth of multicomponent reactions and green chemistry to synthesize ideal heterocyclic compounds. In this study, KF/CP nanoparticles and ZnO-NR were prepared. Identification and characterization of anocatalysts were performed by using FT-IR, XRD, SEM, FE-SEM, BET, DLS and zeta potential. Then, nanocatalysts were used in multicomponent reactions to synthesize oxochromans, benzofurans, quinolines, flavon-3-ols and cyclopentadienes.A convenient and efficient one-pot procedure has been developed for the preparation of novel 2-oxochromene and benzofuran derivatives through the sequential addition/ intramolecular cyclization reactions of 1-(6-hydroxy-2-isopropenyl-1-benzofuran-5-yl)-1-ethanone, activated acetylenic compounds and triphenylphosphine in the presence of catalytic amount of KF/CP nanocatalyst in water at room temperature. Also, the antioxidant activities of the newly synthesized derivatives (61a, 61b, and 63a) were screened by DPPH• radical scavenging and ferric ion reducing potential assays compared to the synthetic antioxidants (TBHQ and BHT). Compounds 61a and 61b were shown good antioxidant activities. A series of novel felavon-3-ols under proficient and green one-pot three-component conditions were designed and synthesized through the aldol condensation/intramolecular cyclization reactions of 1-(6-hydroxy-2-isopropenyl-1-benzofuran-5-yl)-1-ethanone, derivatives of aldehydes and hydrogen peroxide in the presence of catalytic amount of KF/CP nanocatalyst in water at room temperature. Furthermore, to determine the antioxidant properties of the novel felavon-3-ols derivatives, the DPPH• radical scavenging and Fe3+ reducing ability assays were carried out and compared with the synthetic antioxidants (TBHQ and BHT). These compounds showed weak antioxidant activities.A proficient, green and environmentally benign one-pot three-component synthesis of functionalized quinolines was developed by condensation reactions of isatin, activated acetylenic compounds, and alcohols in the presence of KF/CP (NPs) as a heterogeneous base nanocatalyst, at room temperature in water. A three-component condensation was applied for the preparation of cyclopentadiene derivatives through the reaction of primary amines, alkyl propiolate and dialkyl acetylenedicarboxylate in the presence of catalytic amount of ZnO-nanorods (Zn-NR) under solvent-free conditions at 50 oC. The method has proved to be synthetically green, simple, and effective with high atom economy and yield. The catalyst also revealed significant reusability. Moreover, the antioxidant activity and free radical scavenging capacity of the newly synthesized derivatives 70a, 70b, 70c, and 70d was screened using free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays and compared with hydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ). These compounds do not exhibit good DPPH radical scavenging, but they have a desirable FRAP
