Epoxyethane Methoxycarbonylation over a Heterogeneous Catalyst Based on Functionalized Cobalt Carbonyl

Abstract

In this work, we report a new heterogeneous catalyst for the methoxycarbonylation of epoxyethane (EO) to methyl 3-hydroxypropanoate (3-HPM), achieving good yields and recyclability of up to three times with no obvious loss in catalytic activity. The catalysts were prepared through an effective strategy to anchor active cobalt carbonyl species to functionalized silica-based molecular sieves. The successful grafting of functional ligand and cobalt carbonyl cluster was evident through ²⁹Si-MAS NMR and FT-IR studies. Furthermore, an in situ FT-IR study indicates that a binuclear cobalt carbonyl catalyst may undergo a shift from bridged carbonyl to terminal carbonyl in the methoxycarbonylation of EO. According to time-dependent in situ FT-IR spectra in the carbonyl stretching region, the main product and intermediate are both captured, showing a new reaction mechanism different from the previous literature reports. These findings are significant for insight into the relation between the catalytic performance and structure.