4853-04-7Relevant academic research and scientific papers
Copper-catalyzed asymmetric conjugate addition of trialkylaluminium reagents to trisubstituted enones: Construction of chiral quaternary centers
Vuagnoux-D'Augustin, Magali,Alexakis, Alexandre
, p. 9647 - 9662 (2008/12/21)
Me3Al, Et1Al, and vinylalane species undergo enantioselective conjugate addition to a wide range of 2- or 3-substituted enones (cyclopent-2enones, cyclohex-2-enones, 3-methyl cyclohept-2-enone) in the presence of catalytic amount of copper salt (copper thiophene carboxylate, [Cu(CH3-CN)4]BF4 or [CuOTf]2· C6H6) and tropos-phosphoramidite-based ligand. Thus, chiral quaternary centers can be built, with up to 98% ee after rigorous optimization of experimental conditions. It was shown that the main important parameter was the order of the introduction of the reagents. Then, the generated enantioenriched aluminium enolates and the chiral conjugate adducts were functionalized and used for subsequent reactions.
Cu-catalyzed asymmetric conjugate additions of alkylzinc reagents to acyclic aliphatic enones
Mizutani, Hirotake,Degrado, Sylvia J.,Hoveyda, Amir H.
, p. 779 - 781 (2007/10/03)
Cu-catalyzed enantioselective conjugate additions to acyclic aliphatic enones are reported. The resulting enolates may be functionalized intra- and intermolecularly, leading to the formation of an additional C-C bond. The utility of the present method is not limited to reactions involving Et2Zn; a variety of alkylzincs may be used. Moreover, many of the requisite substrates can be easily accessed through catalytic olefin cross metathesis. Copyright
