Oxidative Dimerization of Lithium-Enolates of Esters Promoted by TitaniumTetrachloride
作者:Iwao Ojima、Stephan M. Brandstadter、Robert J. Donovan
DOI:10.1246/cl.1992.1591
日期:1992.8
Oxidative dimerization of lithium ester enoalates is effectively promoted by TiCl4, which serves as a new and efficient synthetic method. Mechanistic study indicates that the reaction proceeds via a radical-like mechanism, but it is not a free radical process.
Dependence of the Reactivities of Titanium Enolates on How They Are Generated: Diastereoselective Coupling of Phenylacetic Acid Esters Using Titanium Tetrachloride
phenylacetic acidesters was easily achieved by treating the esters with TiCl(4) and then adding Et(3)N to the resulting solution. The products consisted of dl- and meso-2,3-diphenylsuccinic acidesters with the Claisen condensation product, and the ratio of these products depended on the reaction conditions. Reaction conditions suitable for high dl selectivity were determined, and a dimer of titanium enolate