title: Synthesis of fully substituted dispirocyclohexanes by organocatalytic [2 + 2 + 2] annulation strategy between 2-arylideneindane-1,3-diones and aldehydes.
abstract: An interesting organocatalytic reaction between 2-arylideneindane-1,3-diones and aldehydes has been developed that gives fully substituted cyclohexanes that bear two all-carbon quaternary centers. The dispirocyclohexanes were obtained in reasonable-to-good chemical yields and with high stereoselectivities (>95:5 d.r. and up to 99% ee) using a catalytic amount of commercially available α,α-l-diphenylprolinol trimethylsilyl ether (5 mol %) and DABCO (20 mol %) in DMF at -20 °C. The reaction proceeds through a unique Michael/Michael/aldol reaction that requires 2 equiv of the 2-arylideneindane-1,3-dione.
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan 116, ROC.
authors.forename: Hsuan-Hao
authors.initials: HH
authors.lastname: Kuan
authors.forename: Chung-Han
authors.initials: CH
authors.lastname: Chien
authors.forename: Kwunmin
authors.initials: K
authors.lastname: Chen
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D003510:Cyclohexanes / Q000737:chemistry*; D004987:Ethers / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D011392:Proline / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D003510:Cyclohexanes; D004987:Ethers; D013141:Spiro Compounds; C525093:alpha,alpha-diphenylprolinol trimethylsilyl ether; D011392:Proline