title: C(sp3)-C(sp3) and C(sp3)-H bond activation of 1,1-disubstituted cyclopentane.
abstract: The unprecedented C(sp(3))-C(sp(3)) bond cleavage of unactivated cyclopentane has been achieved. Rh(I)-catalyzed cycloaddition of allenylcyclopentane-alkynes produced in situ the 9-cyclopentyl-8-rhodabicyclo[4.3.0]nona-1,6-diene intermediates, which subsequently underwent [7+2] cycloaddition via β-C elimination, affording bicyclo[7.4.0]tridecatriene derivatives in good yields. Changing the Rh(I) catalyst effected the Cγ-H bond activation of the common 9-cyclopentyl-8-rhodabicyclo[4.3.0]nona-1,6-diene intermediate to produce the novel spiro[2.4]heptane skeleton in a site-selective manner.
authors.affiliation: Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. mukai@p.kanazawa-u.ac.jp
authors.forename: Chisato
authors.initials: C
authors.lastname: Mukai
authors.forename: Yuu
authors.initials: Y
authors.lastname: Ohta
authors.forename: Yuki
authors.initials: Y
authors.lastname: Oura
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Inagaki
mesh_terms: D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry; D003517:Cyclopentanes / Q000737:chemistry*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D003517:Cyclopentanes; D013141:Spiro Compounds; D012238:Rhodium