A DFT study on the mechanism of cyclopropanation via Cu(acac)(2)-catalyzed diazo ester decomposition

The mechanism of the copper(I)-catalyzed olefin cyclopropanation reaction with dimethyl diazomalonate has been extensively investigated using the DFT method at B3LYP/6-31G* and BP86/SDD/6-31G* levels. All the possible pathways leading first to a metal carbene and then to the cyclopropane product have been studied with ethene as a model substrate and their energetics are demonstrated. Then the suggested mechanisms were applied to a real system: namely, 2,2-dimethyl-4,7-dihydro-1,3-dioxepine.