Iron chloride enhancement of dimethylzinc-mediated radical conjugate addition of ethers and an amine to alkylidenemalonates

The addition of FeCl3 and the use of DMSO as a solvent enabled the radical conjugate addition of a cyclic acetal and a cyclic amine to alkylidenemalonates using a reagent amount (12.5 equiv) of the radical precursors to give Michael addition products in up to 84% yield. This represents a great improvement over the 5% yield obtained under the previously reported conditions.