Silica-supported Active Ni Nanocatalyst for Wittig Reaction

The preparation and characterization of SBA-15 supported Ni catalysts with varying metal loading (1, 2, and 3% by weight) was carried out using the impregnation technique, followed by a rigorous characterization using advanced analytical techniques. The catalytic performance of the synthesized catalysts was evaluated for the Wittig-type olefination reaction, and it was found that the SBA- 15-3Ni catalyst exhibited superior activity for this reaction under mild reaction conditions (70°C and 1 hour). The corresponding stilbenes were obtained in good yield, although with low to average diastereoselectivity. An important feature of this protocol is that the proposed methodology is especially efficient for the synthesis of stilbenes since no additives are required to serve as a hydrogen acceptor. Moreover, the new catalytic system was successfully employed for the synthesis of polymethoxylated and polyhydroxylated stilbenes, including resveratrol and DMU-212, with high yield and easy product isolation. A key advantage of this protocol is that the catalysts can be reused for up to 5 runs without significant loss in catalytic activity, which makes this approach highly sustainable and cost-effective. Additionally, the ligand-free approach proposed in this study is an added advantage, which makes it more attractive for large-scale synthesis of biologically active compounds.