Practical Chan-Evans-Lam Cu(II)-Catalyzed C-O Cross-Couplings: Broadening Synthetic Access to Functionalized Vinylic Ethers

We report a general and effective Cu(OAc)2-catalyzed C-O cross-coupling synthesis of di- and trisubstituted vinylic ethers, enabled by a combination of N-isopropylimidazole ligand and dicumyl peroxide as stoichiometric oxidant. This method couples functionalized vinylic pinacolboronates with various primary and secondary alcohols to provide single-step syntheses of novel and structurally complex vinylic ethers. The optimized conditions do not require excess alcohol reactant, and substantially suppress competing side reactions.