Synthesis of Functionalized Hydroquinones via [Cp*RuCl<sub>2</sub>]<sub>2</sub>-Catalyzed Cocyclization of Alkynes, α,β-Unsaturated Carbonyl Compounds, and Carbon Monoxide
[reaction: see text] Catalytic [2 + 2 + 1 + 1] cocyclization reaction of an alkyne, an alkene, and two molecules of carbonmonoxide, 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