Pd-Catalyzed Ring-Opening of Cyclopropenes for Alkenylation of Phenols: Access to Tetrasubstituted Alkenyl Ethers

This study reports a novel Pd-catalyzed ring-opening of cyclopropenes for the alkenylation of phenols. Proceeding under mild conditions with high atom economy, the reaction enables the synthesis of diverse tetrasubstituted alkenyl ethers in moderate to excellent yields, featuring broad substrate compatibility. Deuterium-labeling experiments revealed that the hydrogen atoms in the newly formed methyl group are predominantly originated from phenols and cyclopropenes. Density functional theory (DFT) calculations revealed that a formal palladium 1,2-migration process might be involved in the transformation.