Remarkable solvent effect on Pd(0)-catalyzed deprotection of allyl ethers using barbituric acid derivatives: Application to selective and successive removal of allyl, methallyl, and prenyl ethers

Pd(0)-catalyzed deprotection of allyl ethers using barbituric acid derivatives in protic polar solvent such as MeOH and aqueous 1,4-dioxane proceeds at room temperature without affecting a wide variety of functional groups. Control of the reaction temperature allows selective and successive cleavage of allyl, methallyl, and prenyl ethers. A study of ligand effects on the deprotection reveals that the improved reactivity in MeOH results from the accelerated oxidative addition to Pd(O).