title: Rhodium(I)-catalyzed direct carboxylation of arenes with CO2 via chelation-assisted C-H bond activation.
abstract: Rh-catalyzed direct carboxylation of unactivated aryl C-H bond under atmospheric pressure of carbon dioxide was realized via chelation-assisted C-H activation for the first time. Variously substituted and functionalized 2-arylpyridines and 1-arylpyrazoles underwent the carboxylation in the presence of the rhodium catalyst and a stoichiometric methylating reagent, AlMe(2)(OMe), to give carboxylated products in good yields. The catalysis is proposed to consist of methylrhodium(I) species as the key intermediate, which undergoes C-H activation to afford rhodium(III), followed by reductive elimination of methane to give nucleophilic arylrhodium(I). This approach demonstrates promising application of C-H bond activation strategy in the field of carbon dioxide fixation.
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, O-Okayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Mizuno
authors.forename: Jun
authors.initials: J
authors.lastname: Takaya
authors.forename: Nobuharu
authors.initials: N
authors.lastname: Iwasawa