An improved cobalt-catalysed alkoxycarbonylation of olefins using secondary phosphine oxide promotors

In general, cobalt-catalysed carbonylations of olefins require high carbon monoxide (CO) pressure and high temperature to proceed efficiently. In contrast, the presence of secondary phosphine oxide (SPO) promotors allows the formation of esters from alkenes and alcohols under comparably milder reaction conditions (typically 120 degrees C, 40 bar). The influence of several types of SPOs was investigated and kinetic studies showed a significant acceleration of the formation of the active cobalt catalyst in the presence of simple diphenylphosphine oxide.