Synthesis of cyclopentenediolates and cyclopentane-1,2-diones by carbonylation of titanacyclobutane complexes prepared by free radical alkylation

The synthesis of titanium cyclopentenediolates by the double carbonylation of titanacyclobutane complexes is reported, a process known as the Bercaw c arbonylation. The reaction is general for a range of titanacyclobutanes pre pared by free radical alkylation of allyltitanium(III) precursors. Titanacy clobutane formation and carbonylation can be conducted in one pot without t he isolation of sensitive intermediates. Subsequent conversion to lithium c yclopentenediolates and cyclopentane-1,2-diones provides access to a range of synthetically valuable organic products.