Pure and Applied Chemistry

Abstract: The cyclopropanation of various alkenes with different diazoester compounds was investigated using two different μ-oxo-bis[(salen)iron(III)] complexes, [Fe(3,3',5,5'-^tBu₄salen)]₂O and [Fe(salen)]₂O. Ethyl diazoacetate (EDA), tert-butyl diazoacetate (^tBDA), and ethyl diazoacetoacetate (EDAA) were used with mono- and disubstituted terminal olefins (styrene and 1,1-diphenyl ethylene, respectively), internal olefin (trans-β-methyl styrene), and an electron-rich alkene (n-butyl vinyl ether). Moderate-to-good cyclopropanation yields were obtained for most substrates.