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

Abstract The rate and selectivity of catalytic enantioselective cyclopropanation of cinnamyl alcohol utilizing bisiodomethyl 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.