129156-86-1Relevant academic research and scientific papers
Asymmetric addition of n-butyllithium to aldehydes: New insights into the reactivity and enantioselectivity of the chiral amino ether accelerated reaction
Granander, Johan,Sott, Richard,Hilmersson, G?ran
, p. 4717 - 4725 (2007/10/03)
Enantioselective butylation of benzaldehyde with n-butyllithium was mediated by a series of chiral lithium amide analogues to give 1-phenylpentanol in good to moderate enantioselectivities. In order to achieve high enantiomeric excess in the reaction, the lithium amide must have a substituent larger than methyl on both the carbon at the stereogenic center and the nitrogen. Computational studies, using semi-empirical (PM3) and density functional (B3LYP) methods, show that the stabilities of the transition states for the chiral lithium amide accelerated butylation of isobutyraldehyde are in agreement with experiments.
Stereoselective reactions, 25. Enantioselective deprotonation of prochiral 4-substituted cyclohexanones by chiral chelated lithium amides
Shirai, Ryuichi,Sato, Daisaku,Aoki, Kazumasa,Tanaka, Masahide,Kawasaki, Hisashi,Koga, Kenji
, p. 5963 - 5972 (2007/10/03)
Enantioselective deprotonation of prochiral 4-substituted cyclohexanones (4a-d) by chiral chelated lithium amides (8a-k) in the presence of excess trimethylsilyl chloride was realized to give the corresponding chiral silyl enol ethers (6a-d) in up to 89% ee. It is shown that enantioselectivity of the reaction is dependent on the solvent used, but becomes almost independent on the solvent in the presence of HMPA. The sense of asymmetric induction can be correlated to the configuration at the chiral carbon bearing amide nitrogen of the lithium amide.
ENANTIOSELECTIVE SYNTHESIS OF β-HYDROXY-α-METHYL CARBONYL COMPOUNDS BY ALDOL REACTION
Ando, Akira,Shioiri, Takayuki
, p. 4969 - 4988 (2007/10/02)
The enantioselective aldol reactions of ketone lithium enolates with aldehydes mediated chiral lithium amides were extensively investigated.The chiral amino ethers 4a-4l and diamines 16a,b were prepared from α-amino acids.The reaction conditions and the s
