Calcined Dolomite: An Efficient and Recyclable Catalyst for Synthesis of α, β-Unsaturated Carbonyl Compounds
- 56 Downloads
Calcined dolomite was utilized as a low-cost and efficient catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as malononitrile and ethyl cyanoacetate to afford substituted α, β-unsaturated carbonyl compounds. Calcination temperature was an important variable which changed the surface areas, textural characteristics and basicity of dolomite catalysts. Among them, natural dolomite was converted to CaO–MgO mixed oxide after calcination at 700 °C, which served as the best catalyst for this reaction. It could be reused for four times without significant decrease of the reactivity. The reaction proceeded smoothly under the magnetic stirring condition at room temperature in excellent yields within short time due to the high surface area and reasonable basicity concentration of dolomite-700 °C catalyst. The attractive features of this procedure were the mild and facile reaction conditions, excellent yields, environmentally friendly reaction profiles and high recyclability, which made it to be an efficient and attractive strategy for the preparation of α, β-unsaturated carbonyl compounds.
KeywordsDolomite Knoevenagel reaction Calcination temperature Basicity Catalysis
The authors gratefully acknowledge the supports from National Natural Science Foundation of China (No. 21606146), Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents (No. 2016RCJJ005), and Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (No. 2018-K29).
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 12.Liu Q, Ai H (2016) Ultrasound promoted synthesis of arylmethylenemalonitriles catalyzed by melamine. J Chem Soc Pak 38(3):565–569Google Scholar
- 30.Leelavathi P, Kumar SR (2005) Niobium (V) chloride catalyzed Knoevenagel condensation: an efficient protocol for the preparation of electrophilic alkenes. J Mol Catal A 240(1):99–102Google Scholar