Agro waste derived nanosilica supported Pd(ll) complex: A protocol for copper free Sonogashira reaction in water

Publication date: Available online 24 June 2019Source: Journal of Organometallic ChemistryAuthor(s): Rajjyoti Gogoi, Rituraj Saikia, Geetika BorahAbstractA palladium (II) complex immobilized onto nanosilica(Pd-imine@nanoSiO2) has been developed and evaluated as a highly efficient, retrievable catalyst for carbon-carbon triple bond activation reactions between aryl halides and terminal alkynes. Nanosilica has been derived from rice husk by simple and eco-compatible methodology. The catalyst has been extensively characterized by techniques such as FT-IR, UV–vis, powder XRD, XPS, SEM-EDX, thermogravimetric analysis, BET surface area measurement. The catalyst can be reused for five consecutive runs without compromising much with the activity. Easy preparation, its long shelf life, air-stability, wide substrate scope, ‘in water’ reactions, easy separability and good recyclability make it an ideal system for Sonogashira cross-coupling reaction. Moreover, various alkyne substrates were efficiently cross-coupled with a broad range of aryl iodides and aryl bromides to afford diaryl alkynes, providing improved yields with low catalyst loading in water. This protocol is also suitable for aliphatic alkynes.Graphical abstract
Source: Journal of Organometallic Chemistry - Category: Chemistry Source Type: research