Encapsulating ruthenium in silica using a single source precursor: Differing outcomes for a cycloaddition reaction
摘要:
The complex [Ru-2(CO)(4)(mu-O2CCH2OSi(OEt)(3))(2)(PPh3)(2)] was used as a single-source precursor to prepare silica encapsulated ruthenium via hydrolysis followed by calcination. While the silica-encapsulated ruthenium catalyst and the molecular precursor both catalysed the [2 + 1] cycloaddition reaction between alkenes and ethyl diazoacetate to form cyclopropanes, the intermediate hydrolysis product partially directed the reaction towards [2 + 3] cycloaddition to form cyclic five-membered pyrazolines.
The invention provides a recirculating reactor for converting a substrate to a product. The reactor comprises a reaction chamber and a recirculation system, said recirculation system comprising a separator. The reaction chamber contains a catalyst, and comprises a chamber body, a chamber inlet and a chamber outlet. The recirculation system is adapted for recirculating liquid from the chamber outlet to the chamber inlet, and the separator is used for separating a by-product from the liquid.