Synthesis of cyclopentenediolates and cyclopentane-l,2-diones by carbonylation of titanacyclobutane complexes prepared by free radical alkylation

Abstract

The synthesis of titanium cyclopentenediolates by the double carbonylation of titanacyclobutane complexes is reported, a process known as the Bercaw carbonylation. The reaction is general for a range of titanacyclobutanes prepared by free radical alkylation of allyltitanium(III) precursors. Titanacyclobutane formation and carbonylation can be conducted in one pot without the isolation of sensitive intermediates. Subsequent conversion to lithium cyclopentenediolates and cyclopentane-l,2-diones provides access to a range of synthetically valuable organic products.