General, Stereoselective Synthesis of (Z)-β,γ-Unsaturated Nitriles Promoted by Samarium Diiodide

A method to obtain (Z)-β,γ-unsaturated nitriles in high or good yields and with moderate or high stereoselectivity is described. The products were achieved through the photoinduced metalation of 3-acetoxy-4-chloronitriles with SmI2. The starting compounds were readily prepared, and a mechanism is proposed to explain this stereoselective β-elimination reaction.