Methoxycarbonylation of propylene oxide: A new way to β-hydroxybutyrate

The methoxycarbonylation of propylene oxide (PO) to methyl β-hydroxybutyrate (MHB) catalyzed by dicobaltoctacarbonyl ([Co2(CO)8]) and 3-hydroxypyridine (3-OH-Py) in methanol system has been studied. The effects of different additives, the molar ratio of 3-OH-Py:Co2(CO)8, temperature, carbon monoxide (CO) pressure, reaction time on the conversion and selectivity have been investigated. The conversion of propylene oxide is 80.4%, and the yield of methyl β-hydroxybutyrate is 74.9% with selectivity 93.2% when the reaction is carried out for 16 h at 80 °C and 6.0 MPa of CO in methanol, with 0.125 mmol of Co2(CO)8, 0.25 mmol of 3-OH-Py. The mechanism of this catalytic reaction has also been proposed.

Graphical abstractMethyl β-hydroxybutyrate was prepared by cobalt-catalyzed carbonylation reaction of propylene oxide and methanol. The effects of reaction parameters such as additive, cobalt sources, carbon monoxide pressure, temperature, etc., were investigated. The mechanism of this catalytic reaction has also been discussed in detail.Figure optionsDownload full-size imageDownload as PowerPoint slide