A variety of new chiral phosphoramidites was synthesised and tested in the copper-catalysed enantioselective conjugate addition of diethylzinc to cyclohexenone and chalcone in order to assess the structural features that are important for stereocontrol. A sterically demanding amine moiety is essential to reach high e.e.’s. Enantioselectivities for chalcones up to 89% and for cyclic enones up to 98% were found. Studies on non-linear effects with the best ligands for both cyclohexenone and chalcone showed clear non-linear effects for both cyclic and acyclic enones.
|Autori:||L.A. ARNOLD; R. IMBOS; MANDOLI A; A.H.M. DE VRIES; R. NAASZ; B.L. FERINGA|
|Titolo:||Enantioselective Catalytic Conjugate Addition of Dialkylzinc Reagents using Copper-Phosphoramidite Complexes; Ligand Variation and Non-linear Effects|
|Anno del prodotto:||2000|
|Digital Object Identifier (DOI):||10.1016/S0040-4020(00)00142-3|
|Appare nelle tipologie:||1.1 Articolo in rivista|