Naphthalenes, isoquinolines, and a benzazocine from zirconocene-copper-mediated coupling of benzocyclobutadiene with nitriles and alkynes.
T V V Ramakrishna, Paul R Sharp
Index: Org. Lett. 5(6) , 877-9, (2003)
Full Text: HTML
Abstract
[reaction: see text] Commercially available 1-bromobenzocyclobutene is a potentially useful synthon particularly with the application of organometallic methodology. Here we show that it is readily converted into Cp(2)Zr(benzocyclobutadiene), which couples with alkynes or nitriles giving five-membered zirconacycles. Treatment of these alkyne- or nitrile-derived zirconacycles with CuCl yields substituted naphthalenes, isoquinolines, or in the presence of MeO(2)C-CC-CO(2)Me, a 3-benzazocine containing an eight-membered ring [corrected].
Related Compounds
Related Articles:
Condensed Cyclobutane Aromatic Compounds. IX. Benzocyclobutenol and Benzocyclobutenone. Cava MP and Muth K.
[J. Am. Chem. Soc. 82(3) , 652-54, (1960)]
1-Bromobenzocyclobutene: a convenient entry into the benzocyclobutene ring system. DeCamp MR and Viscogliosi LA.
[J. Org. Chem. 46(19) , 3918-20, (1981)]
Studies on the syntheses of heterocyclic compounds-DXLV: An alternative synthesis of the protoberberine ring system. Kametani T, et al.
[Tetrahedron 30(9) , 1043-46, (1974)]