Ruthenium Catalyst for the meta-Selective Substitution Reaction

(p-Cymene)bis(mesitylcarboxylato)ruthenium(II) (1), a ruthenium complex used to catalyze C-H bond functionalizations has been recently reported by Ackermann et al. In the presence of catalytic amounts of 1, substituted benzene derivatives are regioselectively alkylated at the meta-position by treatment with secondary alkyl halides in good yield.¹⁾ Furthermore, when o-alkylbenzoic acid derivatives are treated with alkenes and the catalyst 1, meta-alkenylated arenes are provided via decarboxylative C-H bond activation.²⁾ In addition, 1 is effective at C(sp³)-H activation of benzylamine derivatives.³⁾ 1 can be used as a catalyst for various types of aryl functionalization through C-H bond activation.