Free radical-promoted conjugate addition of activated bromo compounds using titanocene(III) chloride as the radical initiator
作者:Samir Kumar Mandal、Samaraesh Jana、Subhas Chandra Roy
DOI:10.1016/j.tetlet.2005.07.007
日期:2005.9
Free radical-promoted conjugate addition of activated bromo compounds to α,β-unsaturated ketones and reactive α,β-unsaturated esters has been described using titanocene(III) chloride (Cp2TiCl) as the radical initiator. Cp2TiCl was prepared in situ from commercially available Cp2TiCl2 and activated zinc dust in THF.
A novel enantioselective C-C bondcleavage has been achieved using palladium catalysts and chiral N,P-bidentate ligands in the asymmetric arylation, vinylation, and allenylation of tert-cyclobutanols. In these reactions, the enantioselective beta-carbon elimination of Pd(II) alcoholate formed in situ is the key step. Treatment of tert-cyclobutanols with arylating reagents in toluene in the presence