Synthesis of Optically Active α-Hydroxy Carbonyl Compounds by the Catalytic, Enantioselective Oxidation of Silyl Enol Ethers and Ketene Acetals with (Salen)manganese(III) Complexes
作者:Waldemar Adam、Rainer T. Fell、Veit R. Stegmann、Chantu R. Saha-Möller
DOI:10.1021/ja9726668
日期:1998.2.1
A set of silyl enol ethers and ketene acetals 1a−h with α- and/or β-phenyl as well as alkyl substituents of different steric bulk has been submitted to the enantioselective catalytic oxidation by chiral (salen)MnIII complexes 3. Highest conversions and best enantioselectivities have been obtained with bleach rather than iodosobenzene as oxygen source for the active oxo−metal species. With regard to
Microorganisms that hydrolyzes α-acetoxyacylophenones were screened, and it was found that Pichia miso IAM 4682, a type culture belonging to yeast, gave the best results. The esterase of this microbe hydrolyzed (R)-acetates in a highly enantioselective manner.
Optically active α-hydroxy ketones 4 have been prepared in high enantioselectivity by the catalytic, enantioselective oxidation of easily available and stable (E)-enol phosphates 2 by (salen) Mn(III) complex.
The catalytic asymmetric synthesis of chiral 2‐hydroxy ketones by using different thiaminediphosphatedependent enzymes, namely benzaldehydelyase from Pseudomonas fluorescens (PfBAL), a variant of benzoylformate decarboxylase from Pseudomonas putida (PpBFD‐L461A), branched‐chain 2‐keto acid decarboxylase from Lactococcus lactis (LlKdcA) and a variant of pyruvate decarboxylase from Acetobacter pasteurianus
Asymmetric α-hydroxy ketone synthesis by direct ketone oxidation using a bimetallic palladium(II) complex
作者:Othman A. Hamed、Arab El-Qisairi、Hanan Qaseer、Emad M. Hamed、Patrick M. Henry、Daniel P. Becker
DOI:10.1016/j.tetlet.2012.03.066
日期:2012.5
The oxidation of ketones by a chiral bimetallic palladium(II) complex in the presence of CuCl2 in THF–water solvents gave an enantioselective synthesis of α-hydroxyketones in catalytic oxidation utilizing an atmosphere of oxygen. The ee’s ranged from 61% to 92%. The reaction was accelerated by addition of strong acid that presumably increases the rate of enolization.