Nanocrystalline ZnO for Knoevenagel Condensation and Reduction of the Carbon,Carbon Double Bond in Conjugated Alkenes

Abstract

A novel efficient and eco-friendly nanocrystalline ZnO catalyst was used for the Knoevenagel condensation and for the reduction of C¼C double bonds at room temperature in the absence of solvents.

An unexpected bifunctional acid base catalysis in IRMOF-3 for Knoevenagel condensation reactions

“…4). In a first approximation, we attribute this increase in activity to a higher content of ZnO impurities in the former sample, since nanocrystalline ZnO has been reported to be active for the Knoevenagel condensation reaction [17,18].…”

Recent developments on nano-ZnO catalyzed synthesis of bioactive heterocycles

“…Using this newly prepared efficient catalytic system they synthesized a series of 1,2,3-triazoles (89) via one-pot three-component reactions of various benzyl halides (88) phenylacetylenes (48) and sodium azide (41) in water under reflux condition (Table 26). During optimization combined nano (CuO-ZnO) showed better catalytic efficacy than the individual nano-ZnO or nano-CuO.…”

“…In many occasions, it was also synthesized in biogenic pathway using various plant extracts [46]. Thereby, past decade has seen tremendous applications of various morphologies of nano-ZnO as catalysts in different organic name reactions that include Mannich reaction [47], knoevenagel condensation [48,49] and in various organic transformations, such as the synthesis of antiplatelet drug (Clopidogrel) [50], phosphonomalonates [51], ferrocenylphosphonates [52], 3-indolyl-3-hydroxy oxindoles [53], β-acetamido ketones/esters [54], O-acylation of alcohol [55], enamination of 1,3-dicarbonyls [56] and β-amino carbonyl compounds [57], etc.…”

Highly efficient one-pot three-component Mannich reaction catalyzed by ZnO-nanoparticles in water

“…Metal oxides exhibit both Lewis acid and Lewis base character at their surface. 8 Metal [10][11][12][13] The Mannich-type reaction is a classic protocol for the synthesis of β-amino carbonyl compounds, which are important intermediates for the construction of various nitrogen-containing natural products and pharmaceuticals and it is a reaction with high atom-economy. 14 33 and heteropoly acids.…”