Ruthenium-Catalyzed C-H Allylation of Alkenes with Allyl Alcohols via C-H Bond Activation in Aqueous Solution.

A robust Ru(II)-catalyzed C-H allylation of electron-deficient alkenes with allyl alcohols in aqueous solution is reported. This method provides a straightforward and efficient access to the synthetically useful 1,4-diene skeletons. With the assistance of the N-methoxycarbamoyl directing group, this allylation reaction features a broad substrate scope with good functional group tolerance, excellent regio- and stereoselectivity, absence of metal oxidants, water-tolerant solvents, and mild reaction conditions. The mechanistic studies indicate that the process of the reversible C-H bond ruthenation is assisted by acetate, and the rate-determining step is unlikely to be the step of C-H bond cleavage.