Simmons-Smith Cyclopropanation Reaction

The Simmons-Smith cyclopropanation reaction is a classic method used to install a cyclopropane moiety from a parent alkene. The reaction is typically conducted using diiodomethane in combination with metallic zinc and copper (Zn/Cu). Zn/Cu can be replaced with diethylzinc, which is known as the Furukawa modification.¹⁾ The Simmons-Smith reaction has considerable advantages over other cyclopropanation methods as it does not require the use of the highly hazardous diazomethane. In addition, the reaction has a wide functional group tolerance including with alkynes, carbonyls, alcohols, ethers, and others and it proceeds stereospecifically.