Catalytic enantioselective cyclopropanation with bis(halomethyl)zinc reagents. I. Optimization of reaction protocol

Article abstract of DOI:10.1016/0040-4039(95)00258-E

The rate and selectivity of catalytic enantioselective cyclopropanation of cinnamyl alcohol utilizing bis-iodomethyl zinc and 4a/4b is greatly dependent on the order of addition of the reagents. The independent preformation of the ethylzinc cinnamyloxide and bis(iodomethyl)zinc was found to be crucial. The reaction displayed autocatalytic behavior which was shown to be due to the generation of zinc iodide.