Regioselective alkenylation of aromatic ketones with alkenylboronates using a RuH₂(CO)(PPh₃)₃ catalyst via carbon - Hydrogen bond cleavage

(Chemical Equation Presented) The ruthenium-catalyzed alkenylation of C-H bonds with alkenylboronates has been explored for a series of aromatic ketones. The coupling reaction of pivalophenone (1) with 2-isopropenyl-5,5-dimethyl[1,3, 2]dioxaborinane (2) gave the corresponding isopropenylation product in 73% yield. In the case of the reaction of a sterically congested alkenylboronate, such as 2-methylpropenylboronate (8), the yield was decreased slightly. When β-styrylboronates were used, the corresponding coupling products were obtained in good yields. The reaction of acetophenone with α- styrylboronate afforded the corresponding 1:1 coupling product, exclusively.