127181-69-5Relevant articles and documents
[1,2]-Wittig rearrangement of enantio-defined α-alkoxyalkyllithiums: Structural requirement and steric course at the Li-bearing terminus
Tomooka, Katsuhiko,Igarashi, Tatsuya,Nakai, Takeshi
, p. 5927 - 5932 (1994)
The [1,2]-Wittig rearrangements of enantio-defined α-benzyloxypropyllithium and its (R)-α-methylbenzyloxy analogs, generated from the enantio-enriched stannanes via Sn/Li exchange, are shown to proceed predominantly with inversion of configuration at the
Kinetic resolution when the chiral auxiliary is not enantiomerically pure: Normal and abnormal behavior
Luukas, Timo O.,Girard, Christian,Fenwick, David R.,Kagan, Henri B.
, p. 9299 - 9306 (1999)
Kinetic resolutions with enantioimpure chiral auxiliaries (reagents or catalysts) are considered, and a kinetic treatment for various rate laws is described. A useful parameter, the apparent stereoselectivity factor, is defined and correlated to the enantiomeric excess of the chiral auxiliary. Deviations from the regular laws are possible (asymmetric amplification or depletion). These anomalies have their origins in the same phenomena that cause nonlinear effects in enantioselective catalysis. Asymmetric amplifications have been experimentally observed.
Asymmetric Synthesis of Optically Active Alcohols with Two Chiral Centres from a Racemic Aldehyde by the Selective Addition of Dialkylzinc Reagents Using Chiral Catalysts
Niwa, Seiji,Hatanaka, Toshihiro,Soai, Kenso
, p. 2025 - 2027 (2007/10/02)
Optically active alcohols with two chiral centres have been obtained in good to high e.e.s (enantiomeric excesses) from racemic 2-phenylpropanal 1 by diastereo- and enantio-selective addition of dialkylzinc reagents using (1S,2R)-(-)-N,N-dibutylnorephedrine (DBNE) and (S)-(+)-diphenyl(1-methyl-pyrrolidin-2-yl)methanol (DPMPM) as chiral catalysts.It was found that in the presence of (1S,2R)-(-)-DBNE, dialkylzinc selectively attacked racemic 1 from the Si-face of the aldehyde 1 regardless of the configuaration of 1 and that (S)-1 reacted faster with dialkylzinc than did (R)-1.
