Using this whole-cell biocatalyst, efficient conversion of prochiral ketones to chiral alcohols was achieved: 66% acetophenone was reduced to (R)-phenylethanol over 12 h, whereas only 19% (R)-phenylethanol was formed under the same conditions with cells containing ADH and FDH genes but without PNT genes.
Lithium aluminum hydride (LAH) modified with chiral alkoxide ligands may be used to synthesize chiral alcohols in good yield and high enantioselectivity. Chelating ligands such as BINOL are used to avoid disproportionation and background reduction by LAH. Chiral diamines and amino alcohols have also been used to modify LAH for enantioselective reductions.
New Synthesis of Chiral Oxazolidin-2-ones
Reduction via the net transfer of hydrogen from one organic molecule to another is known as . Transfer hydrogenation to ketones leads to alcohols (the ), and in the presence of a chiral transition metal catalyst, this process may be rendered enantioselective. In the presence of a chiral diamine, ruthenium catalyzes the enantioselective transfer hydrogenation of aryl ketones with isopropanol. Other metals that have been employed include samarium(III), iridium(I), and rhodium(I).
Dynamic kinetic resolution in asymmetric synthesis - Wikipedia
N2 - Chiral dendrimers with three or six β-amino alcohols on hyperbranched hydrocarbon chain-ends were synthesized. These macromolecules can act as chiral catalysts for the enantioselective addition of dialkylzincs to aldehydes. The corresponding secondary alcohols are obtained in high enantiomeric excess (up to 86% e.e.). (C) 2000 Elsevier Science Ltd.
"Asymmetric synthesis of chiral amines and alcohols …
T1 - Synthesis of chiral dendrimers with a hydrocarbon backbone and application to the catalytic enantioselective addition of dialkylzincs to aldehydes
Enantioselective Synthesis of Chiral Tertiary Alcohols
Because lithium amides are strongly basic, they can often effect the removal of otherwise stubborn protons, such as those positioned at bridgehead carbons. This idea was applied to a kinetic resolution in the synthesis of (+)-clusianone (Eq. 13). Treatment of racemic starting material with chiral lithium amide and quenching with prenyl bromide permitted the separation of the enantioenriched, unfunctionalized product from the essentially racemic functionalized product. The former was carried on to (+)-clusianone.
Biocatalytic Synthesis of Chiral Alcohols and Amino Acids for ..
Chiral dendrimers with three or six β-amino alcohols on hyperbranched hydrocarbon chain-ends were synthesized. These macromolecules can act as chiral catalysts for the enantioselective addition of dialkylzincs to aldehydes. The corresponding secondary alcohols are obtained in high enantiomeric excess (up to 86% e.e.). (C) 2000 Elsevier Science Ltd.
About us_Shanghai Chiral Chemicals Inc.
Some chiral amine precursors are commercially available; however, it is common to prepare the chiral amine from simpler starting materials. Recent reviews have addressed the state of the art of the synthesis of chiral amines. Common starting materials for the synthesis of chiral amines precursors include proline, phenylglycine, norephedrine, α-methylbenzylamine, and chelating diamines.