A Stereoselective Inverting sec-Alkylsulfatase for the Deracemization of sec-Alcohols
摘要:
A metallo-beta-lactamase-type alkylsulfatase was found to catalyze the enantioselective hydrolysis of sec,alkylsulfates with strict inversion of configuration. This catalytic event, which does not have an analog in chemocatalysis, yields homochiral (S)-configurated alcohols and nonreacted sulfate esters. The latter could be converted into (S)-sec-alcohols as the sole product in up to > 99% ee via a chemoenzymatic deracemization protocol on a preparative scale.
MIB: an advantageous alternative to DAIB for the addition of organozinc reagents to aldehydes
作者:William A. Nugent
DOI:10.1039/a904042k
日期:——
3-exo-Morpholinoisoborneol (MIB) catalyzes the addition of organozinc reagents to aldehydes in high enantiomeric excess and provides several advantages over the venerable amino alcohol ligand DAIB.
An Amino Alcohol Ligand for Highly Enantioselective Addition of Organozinc Reagents to Aldehydes: Serendipity Rules
作者:William A. Nugent
DOI:10.1021/ol0259488
日期:2002.6.1
bis(2-bromoethyl) ether. Subsequent hydrogenation over 5% Rh on alumina in the presence of morpholine unexpectedly stops at the hexahydro derivative 4. Amino alcohol 4 promotes the enantioselectiveaddition of diethylzinc to aldehydes at room temperature in up to 99% enantiomeric excess.
Practical Synthesis of (<i>S</i>)‐(+)‐3‐Octanol by Lipase‐Catalyzed Enantioselective Acetylation
作者:Yoshifumi Yuasa、Yoko Yuasa
DOI:10.1080/00397910600616651
日期:2006.7
Abstract (S)‐(+)‐3‐Octanol (S)‐1 was prepared in high enantiomeric excess through catalyzed acetylation of racemic alcohol 1 by using lipase from Candida antarctica (Chirazyme L‐2) in the presence of vinyl acetate in toluene at 30°C. The pure (S)‐1 was obtained in 73% isolated yield with 62% conversion. Moreover, acetate (R)‐2 was converted to (S)‐1 via mesylation and followed by hydrolysis using sodium