1309474-30-3Relevant academic research and scientific papers
Formation of quaternary stereogenic centers by copper-catalyzed asymmetric conjugate addition reactions of alkenylaluminums to trisubstituted enones
Mueller, Daniel,Alexakis, Alexandre
supporting information, p. 15226 - 15239 (2013/11/06)
Alkenylaluminums undergo asymmetric copper-catalyzed conjugate addition (ACA) to β-substituted enones allowing the formation of stereogenic all-carbon quaternary centers. Phosphinamine-copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96 % ee) were obtained for the addition of alkenylalanes to β-substituted enones. Two strategies for the generation of the requisite alkenylaluminums were explored allowing for the introduction of aryl- and alkyl-substituted alkenyl nucleophiles. Moreover, alkyl-substituted phosphinamine (SimplePhos) ligands were identified for the first time as highly efficient ligands for the Cu-catalyzed ACA. Chiral synthesis made easy: The copper-catalyzed conjugate addition of alkenylaluminum reagents to 3-substituted cyclic enones allows for the formation of all-carbon chiral quaternary centers (see scheme; CuTC=copper(I) thiophene-2-carboxylate). Chiral phosphinamine (SimplePhos) ligands were found to be highly efficient for this transformation.
New experimental conditions for tandem hydroalumination/Cu-catalyzed asymmetric conjugate additions to β-substituted cyclic enones
Mueller, Daniel,Tissot, Matthieu,Alexakis, Alexandre
supporting information; experimental part, p. 3040 - 3043 (2011/08/05)
Readily available alkenylalanes, arising from hydroalumination of unprotected terminal alkynes, have been directly employed for the copper-catalyzed asymmetric conjugate addition (ACA) to β-substituted cyclic enones. The desired products, containing a qua
