Cu(I)-catalyzed asymmetric α-hydroxylation of β-keto esters in the presence of chiral phosphine-Schiff base-type ligands

Chiral phosphine-Schiff base-type ligand L1 prepared from (R)-(−)-2-(diphenylphosphino)-1,1′-binaphthyl-2′-amine was found to be a fairly effective ligand for Cu(I)-promoted enantioselective α-hydroxylation of β-keto esters using oxaziridine 2a as the oxidant to give the corresponding products in high yields along with moderate enantioselectivities.

Graphical abstractChiral phosphine-Schiff base type ligand L1 prepared from (R)-(−)-2-(diphenylphosphino)-1,1′-binaphthyl-2′-amine was found to be a fairly effective chiral ligand for Cu(I)-promoted enantioselective α-hydroxylation of β-keto esters using oxaziridine 2a as the oxidant to give the corresponding products in high yields and with moderate enantioselectivities.Figure optionsDownload full-size imageDownload as PowerPoint slide

(R,E)-3-((2′-(Diphenylphosphino)-1,1′-binaphthyl-2-ylimino)methyl)-6-nitrobenzene-1,2-diolC39H28NO2PEe = 100%[α]2020=+108 (c 0.4, CHCl3)Source of chirality: resolutionAbsolute configuration: (R)