Synthesis of functionalized hydroquinones via [Cp*RuCl2]2-catalyzed cocyclization of alkynes, α,β-unsaturated carbonyl compounds, and carbon monoxide

Catalytic [2 + 2 + 1 + 1] cocyclization reaction of an alkyne, an alkene, and two molecules of carbon monoxide, leading to functionalized hydroquinones, was studied. Using [Cp*RuCl2](2) as a catalyst, we found that a variety of electron-deficient alkenes, such as alpha,beta-unsaturated ketones, esters, amides, and nitriles, can be employed as an alkene coupling partner to give the corresponding hydroquinones.