Iron-Catalyzed Diastereoselective Synthesis of α-(Methoxycarbonyl)allylsilanes

Stereodefined polysubstituted α-(methoxycarbonyl)allylsilanes were synthesized through iron-catalyzed conjugate additions between 1-(trimethylsilyl)allene-1-carboxylates and Grignard reagents in good to excellent yields. The use of Et2O as solvent for Grignard reagents was found to be very important for the diastereoselectivity of the reaction. Applications of the prepared allylic silanes for the stereocontrolled synthesis of α,β-alkenoates, a β,γ-alkenoate, and an allylic fluoride have been demonstrated.