title: Annulative π-Extension (APEX) of Heteroarenes with Dibenzosiloles and Dibenzogermoles by Palladium/o-Chloranil Catalysis.
abstract: Annulative π-extension (APEX) reactions of heteroarenes are described herein. A catalytic system comprising a cationic palladium species and o-chloranil using dimethyldibenzosiloles as π-extending agents enabled the extension of the π-system of benzo[b]thiophenes. π-Extended dibenzofurans and carbazoles could also be obtained from benzofuran and N-tosylindole, respectively, with dimethyldibenzogermole as a germanium-based π-extending agent. Mechanistic investigations indicated two possible reaction pathways involving carbopalladation-based double C-H arylation of benzothiophene or formal cycloaddition/oxidation cascades.
authors.affiliation: Graduate School of Science, Nagoya University , Chikusa, Nagoya 464-8602, Japan.
authors.forename: Kyohei
authors.initials: K
authors.lastname: Ozaki
authors.affiliation: Graduate School of Science, Nagoya University , Chikusa, Nagoya 464-8602, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Matsuoka
authors.affiliation: Graduate School of Science, Nagoya University , Chikusa, Nagoya 464-8602, Japan.
authors.forename: Hideto
authors.identifier: 0000-0002-4034-6247
authors.initials: H
authors.lastname: Ito
authors.affiliation: Graduate School of Science, Nagoya University , Chikusa, Nagoya 464-8602, Japan.|JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University , Chikusa, Nagoya 464-8602, Japan.|Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University , Chikusa, Nagoya 464-8602, Japan.
authors.forename: Kenichiro
authors.identifier: 0000-0001-5227-7894
authors.initials: K
authors.lastname: Itami