Abstract

An economical and environmentally friendly heterogeneous base catalyst has been developed from a waste freshwater mussel shell and employed successfully for the synthesis of 4H-pyrans in an aqueous medium at ambient temperature. 2-arylidenemalononitrile, an intermediate of 4H-pyran reaction, was also prepared using the same catalyst. The catalyst was characterized by FT-IR, XRD, XRF, EDS, and SEM. Analytical tools such as XRF and EDS explored the presence of calcium oxide as a main component in the mussel shell, while the XRD pattern showed crystalline nature and SEM image displayed porous surface with irregular cavities. The catalyst exhibited unprecedented performance in the one-pot three-component condensation reaction of C–H activated acidic compounds with aromatic aldehydes and malononitrile in the green reaction medium and offered pure products without chromatographic separation.

中文翻译：

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贻贝废壳作为在水性介质中合成多官能化4 H-吡喃的高效多相催化剂

摘要

已经从废弃的淡水贻贝壳中开发了一种经济，环保的多相碱催化剂，并成功地用于环境温度下在水性介质中合成4 H-吡喃。2-芳基丙二腈，中间体4 H-吡喃反应也使用相同的催化剂制备。通过FT-IR，XRD，XRF，EDS和SEM对催化剂进行表征。XRF和EDS等分析工具探讨了贻贝壳中主要成分是氧化钙的存在，而XRD图谱显示了晶体性质，SEM图像显示了具有不规则空腔的多孔表面。在绿色反应介质中，C–H活化的酸性化合物与芳族醛和丙二腈的一锅三组分缩合反应中，该催化剂表现出空前的性能，提供了无需色谱分离的纯净产物。