Simmons–Smith reaction

Regioselectivity of Pyridine-Diimine (PDI)–Cobalt-Catalyzed Simmons–Smith-Type Cyclopropanation: Alkene Substitution Patterns and the Methylene-Transfer Mechanism

The Simmons–Smith reaction constructs cyclopropanes by transferring a methylene group to an alkene carbon–carbon double bond. In the classical reaction, diiodomethane (CH₂I₂) and a zinc–copper couple generate a zinc carbenoid reagent that transfers a CH₂ unit to the alkene, generally with ...