On the way to chiral copper(I) arenethiolate catalysts for the enantioselective conjugate addition of methyl lithium and methyl magnesium iodide to benzylideneacetone

Enantioselective Conjugate Addition of Dialkylzinc and Diphenylzinc to Enones Catalyzed by a Chiral Copper(I) Binaphthylthiophosphoramide or Binaphthylselenophosphoramide Ligand System

“…To the best of our knowledge, the enantioselectivities and reaction rates achieved here are one of the best yet results for the Cu-catalyzed enantioselective conjugate addition to enones. In addition, we confirmed that this series of chiral phosphoramides was a novel type of S,N-bidentate ligands through 31 P NMR, 13 C NMR spectroscopic experiments. We deduced that the mechanism of asymmetric Michael addition in our reaction system may be a bimetallic catalytic process and the acidic proton (H) of thiophosphoamide in the ligands plays a significant role in the formation of the active species.…”

“…The enantioselectivity and reaction rate achieved here are one of the best results yet for the Cu-catalyzed conjugate addition to enones. It was revealed that this series of chiral phosphoramides was a novel type of S,N-bidentate ligands on the basis of 31 P NMR and 13 C NMR spectroscopic investigations. The mechanism of this asymmetric conjugate addition system has been investigated as well.…”

Copper-catalyzed asymmetric conjugate addition of Grignard reagents to cyclic enones

“…Shortly after this seminal work was published, various catalytic systems were developed based on copper thiolates (24)(25)(26)(27)(28)(29)(30) and monophosphine ligands (31)(32)(33)(34), although in these systems, enantioselectivities rarely reached the 90% enantiomeric excess (ee) level. Notable exceptions are the two literature reports of 92% ee in the addition of BuMgCl to cyclic enones.…”

“…In principle, diphosphines do not match with the metal-differentiating coordination concept (32). It should be emphasized that until now, most successful ligands in the field of copper-catalyzed 1,4-addition of Grignard reagents fulfill the criteria of combining P, S, or Se with N or O donor atoms in their structure to coordinate selectively with Cu and Mg of the organometallic species, respectively (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34). Among the most important bidentate ligands in asymmetric catalysis are ferrocenyl diphosphine ligands, especially TaniaPhos (1; Fig.…”

Copper‐catalyzed Enantioselective Conjugate Addition Reactions of Organozinc Reagents

“…Although Lippard [13] used a chiral N,N 0 -dialkylaminotropone imine copper(I) catalyst in his pioneering work on the asymmetric 1,4-addition of n-BuMgBr to 2-cyclohexenone, nearly all subsequent conjugate additions of Grignard reagents with high enantioselectivities have been performed with copper(I) salts in the presence of chiral sulfur or phosphorus ligands. Chiral ligands and catalysts, with the enantioselectivities achieved to date using Grignard reagents, are summarized in Scheme 7.2 [13][14][15][16][17][18][19].…”