NOVEL RUTHENIUM-CATALYZED CROSS-CARBONYLATION OF ALKYNES AND 2-NORBORNENES TO HYDROQUINONES

Unsymmetrically substituted hydroquinones were obtained in. high yield s by the novel ruthenium-catalyzed cross-carbonylation of alkynes and 2-norbornenes. For example, treatment of 4-octyne and 2-norbornene wit h 2 mol % Ru-3(CO)(12) in N-methylpiperidine under 60 atm of carbon mo noxide at 140 degrees C for 20 h gave the corresponding hydroquinone, yclo[6.2.1.0(2,7)]undeca-2(7),3,5-triene-3,6-diol, in 85% yield. The r eaction apparently involves a maleoyl-ruthenium intermediate which is generated by the reaction of an alkyne and two molecules of carbon mon oxide on the ruthenium.