title: Double C-H functionalization in sequential order: direct synthesis of polycyclic compounds by a palladium-catalyzed C-H alkenylation-arylation cascade.
abstract: Palladium-catalyzed cascade C-H alkenylation and arylation provides convenient access to polycyclic aromatic compounds. Treatment of 3-bromoaniline derivatives bearing a bromocinnamyl group on the nitrogen atom with a catalytic amount of [Pd(OAc)(2)] and PCy(3)·HBF(4) in the presence of Cs(2)CO(3) in dioxane affords naphthalene-fused indole derivatives in good yields. This double cyclization reaction is also applicable to heterocyclic substrates, giving fused indoles containing a heteroaromatic ring such as dibenzofuran, dibenzothiophene, carbazole, indole, or benzofuran through heterocyclic C-H arylation. When using a 2,6-unsubstituted aniline derivative, the first C-H arylation preferentially proceeds at the more hindered position of the aniline ring.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. hohno@pharm.kyoto-u.ac.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ohno
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Iuchi
authors.forename: Naoto
authors.initials: N
authors.lastname: Kojima
authors.forename: Takehiko
authors.initials: T
authors.lastname: Yoshimitsu
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Fujii
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D000478:Alkylation; D001572:Benzofurans / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006860:Hydrogen Bonding; D010165:Palladium / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D001572:Benzofurans; D011083:Polycyclic Compounds; D010165:Palladium