A chiral oxazaborolidinone-promoted aldol reaction with a silyl ketene acetal from ethyl 1,3-dithiolane-2-carboxylate. Synthesis of acetate aldols in high enantiomeric purity
作者:Syun-ichi Kiyooka、Mostofa Abu Hena
DOI:10.1016/0957-4166(96)00265-0
日期:1996.8
Asymmetric synthesis of dithiolane aldols 3 was achieved in good yields by using silyl ketene acetal 1, derived from ethyl 1,3-dithiolane-2-carboxylate, in the chiral oxazaborolidinone (L-1 and D-2)-promoted aldol reaction and desulfurization of 3 resulted in production of acetate aldols 4 in high enantiomerc purity.
samarium(II) iodide mediated asymmetric Reformatsky-type reaction of chiral 3-bromoacetyl-2-oxazolidinones with various aldehydes was studied. A series of chiral 4-substituted 2-oxazolidinones 1-3 and 5,5-disubstituted "SuperQuat" oxazolidinones 4-5 were employed as chiral auxiliaries of the alpha-bromoacetic acid. The reaction of 1 with various aldehydes gave the alpha-unbranched beta-hydroxy carboximides
A Chiral 6-Membered <i>N</i>-Heterocyclic Carbene Copper(I) Complex That Induces High Stereoselectivity
作者:Jin Kyoon Park、Hershel H. Lackey、Matthew D. Rexford、Kirill Kovnir、Michael Shatruk、D. Tyler McQuade
DOI:10.1021/ol1021756
日期:2010.11.5
A chiral 6-membered annulated N-heterocyclic (6-NHC) copper complex that catalyzes β-borylations with high yield and enantioselectivity was developed. The chiral 6-NHC copper complex is easy to prepare on the gram scale and is very active, showing 10 000 turnovers at 0.01 mol % of catalyst without significant decrease of enantioselectivity and with useful reaction rates.
Stereoselective Enzymatic Synthesis of Chiral Alcohols with the Use of a Carbonyl Reductase from <i>Candida </i><i>m</i><i>agnoliae</i> with Anti-Prelog Enantioselectivity
作者:Dunming Zhu、Yan Yang、Ling Hua
DOI:10.1021/jo0603328
日期:2006.5.1
carbonyl reductases with anti-Prelog enantioselectivity, the activity and enantioselectivity of a carbonyl reductase from Candida magnoliae have been examined with various ketones of diverse structures. This carbonyl reductasecatalyzed the reduction of a series of ketones, α- and β-ketoesters, to anti-Prelog configurated alcohols in excellent optical purity. The usefulness of this carbonyl reductase has