title: Intramolecular aromatic carbenoid insertion of biaryldiazoacetates for the regioselective synthesis of fluorenes.
abstract: The rhodium- or copper-catalyzed intramolecular aromatic carbenoid insertion of biaryldiazoacetates offers a convenient route to fluorene carboxylates with high yields. Whereas, thermal conditions provided a mixture of two regioisomeric products when substituted biaryldiazoacetates were employed as substrates. The developed catalytic conditions displayed an excellent level of regioselectivity, presumably owing to steric effects. The insertion mechanism was assumed to be an electrophilic aromatic substitution, which was supported by preliminary mechanistic studies. A chloro-substituted fluorene derivative was efficiently synthesized and utilized as a base-sensitive protecting group of amines.
authors.affiliation: Molecular-Level Interface Research Center and Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors.forename: Jinho
authors.initials: J
authors.lastname: Kim
authors.forename: Youhwa
authors.initials: Y
authors.lastname: Ohk
authors.forename: Sae Hume
authors.initials: SH
authors.lastname: Park
authors.forename: Yousung
authors.initials: Y
authors.lastname: Jung
authors.forename: Sukbok
authors.initials: S
authors.lastname: Chang
mesh_terms: D000085:Acetates / Q000737:chemistry; D001391:Azo Compounds / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D005449:Fluorenes / Q000138:chemical synthesis*; D012238:Rhodium / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000085:Acetates; D001391:Azo Compounds; D005449:Fluorenes; D003300:Copper; D012238:Rhodium