Cu(I)-catalyzed asymmetric α-hydroxylation of β-keto esters in the presence of chiral phosphine-Schiff base-type ligands
作者:Jia-Jun Jiang、Jian Huang、De Wang、Mei-Xin Zhao、Fei-Jun Wang、Min Shi
DOI:10.1016/j.tetasy.2010.05.011
日期:2010.4
Chiralphosphine-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-ketoesters using oxaziridine 2a as the oxidant to give the corresponding products in high yields along with moderate enantioselectivities.
Seen to be green: A highly efficient and green method for catalyzing the enantioselective photooxygenation of β‐keto esters with molecular oxygen in the presence of chiral phase‐transfer catalysts has been developed. High yields (up to 93 %) and good enantiomeric excesses (up to 75 %) could be obtained, and a plausible reaction mechanism has been proposed to explain the outcome of the reaction.
facile, economical and environmentally friendly strategy has been developed for the α-hydroxylation of β-ketoesters and β-keto amides with peroxides via radical cross-coupling reaction in water under open-air conditions. This protocol allows a convenient access to various α-hydroxy-β-keto esters and α-hydroxy-β-keto amides with up to 92% yield (34 examples). Moreover, the reaction was successfully