Tuning Reactivity and Chemoselectivity in Electron Transfer Initiated Cyclization Reactions: Applications to Carbon−Carbon Bond Formation
作者:John R. Seiders、Lijun Wang、Paul E. Floreancig
DOI:10.1021/ja029139v
日期:2003.3.1
demonstrate that the scope of our electrontransfer initiated cyclization reaction can be significantly broadened by exploiting the relationship between the oxidation potentials of homobenzylic ethers and the mesolytic benzylic carbon-carbonbond dissociation energies of their radical cations. By lowering the oxidation potential of the electrophore and the benzylic carbon-carbonbond dissociation energy, we
Structure−Reactivity Relationships in Oxidative Carbon−Carbon Bond Forming Reactions: A Mild and Efficient Approach to Stereoselective Syntheses of 2,6-Disubstituted Tetrahydropyrones
作者:Lijun Wang、John R. Seiders、Paul E. Floreancig
DOI:10.1021/ja046125b
日期:2004.10.1
Homobenzylic ethers with pendent enol acetate nucleophiles undergo highly efficient cleavage reactions followed by 6-endo cyclizations to form 2,6-disubstituted tetrahydropyrones with excellent stereocontrol at room temperature in the presence of the mild oxidant ceric ammonium nitrate. Cyclizations proceed through either stabilized or nonstabilized oxocarbeniumions. Structure-reactivity relationships