title: One-Step Annulative π-Extension of Alkynes with Dibenzosiloles or Dibenzogermoles by Palladium/o-chloranil Catalysis.
abstract: Reliable and short synthetic routes to polycyclic aromatic hydrocarbons and nanographenes are important in materials science. Herein, we report an efficient one-step annulative π-extension reaction of alkynes that provides access to diarylphenanthrenes and related nanographene precursors. In the presence of a cationic palladium/o-chloranil catalyst system and dibenzosiloles or dibenzogermoles as π-extending agents, a variety of diarylacetylenes are transformed successfully into 9,10-diarylphenanthrenes in a single step with good functional-group tolerance. Furthermore, double π-extension reactions of 1,4-bis(phenylethynyl)benzene and diphenyl-1,3-butadiyne are demonstrated, affording oligoarylene products, which show potential for application in the synthesis of larger polycyclic aromatic hydrocarbons and nanographenes.
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: Keiichiro
authors.initials: K
authors.lastname: Murai
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: Katsuaki
authors.initials: K
authors.lastname: Kawasumi
authors.affiliation: Graduate School of Science, Nagoya University, Chikusa, Nagoya, 464-8602, Japan.
authors.forename: Hideto
authors.initials: H
authors.lastname: Ito
authors.affiliation: Graduate School of Science, Nagoya University, Chikusa, Nagoya, 464-8602, Japan.|Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8601, Japan.|JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University, Chikusa, Nagoya, 464-8602, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Itami
keywords: alkynes; dibenzosiloles; palladium; polycyclic aromatic hydrocarbons; π-extension