RuH-Catalyzed Synthesis of 1,3-Diaryl Ketones via Cross-Coupling of Aromatic Enones with Aromatic Aldehydes and Mechanistic Insights

RuHCl(CO)(PPh3)(3)-catalyzed cross-coupling of alkenyl ketones with aldehydes has been extended to the synthesis of 1,3-diaryl 1,3-diketones. The reaction has been successfully applied to the synthesis of PPT (propyl pyrazole triol), a selective estrogen receptor modulator compound. A study of the stoichiometric reaction of phenyl vinyl ketone with RuHCl(CO)(PPh3)(3) has revealed that the beta-ruthenium ketone PhCOCH2CH2RuCl(CO)(PPh3)(2), a five-membered ruthenacycle is formed with liberation of one molecule of PPh3. The observed catalytic activity of this ruthenacycle in the presence of PPh3 suggests that it serves as a resting state, in equilibrium with an oxa-pi-allyl ruthenium species, which is the key coupling partner with aldehyde substrates.

Automated summary

The RuHCl(CO)(PPh3)(3)-catalyzed cross-coupling reaction has been extended to synthesize 1,3-diaryl 1,3-diketones, and also applied to the synthesis of PPT (propyl pyrazole triol). A study revealed the formation of a five-membered ruthenacycle, beta-ruthenium ketone, during the reaction.