Pentaphenylcyclopentadienyl ruthenium complexes (3) are excellent catalysts for the racemization of secondary alcohols at ambient temperature. The combination of this process with enzymatic resolution of the alcohols results in a highly efficient synthesis of enantiomericallypure acetates at room temperature with short reaction times for most substrates. This new reaction was applied to a wide range
Synthesis of Chiral Aromatic Alcohols: Use of New C<sub>2</sub>-Symmetric Rh<sup>III</sup>Cp∗, Ru<sup>II</sup>(cymene), or Ru<sup>II</sup>(benzene) Complexes Containing Chiral Diaminocyclohexane Ligand as Asymmetric Transfer Hydrogenation Catalyst
Abstract Twelve chiral secondary alcohols were synthesized by asymmetrictransferhydrogenation (ATH) using C2-symmetric bis(sulfonamide) ligand (2) derived from (1R,2R)-cyclohexane-1,2-diamine and complexed with [RhCl2Cp*]2, [RuCl2(cymene)]2, or [RuCl2(benzene)]2 and then used in situ in the reduction of prochiral ketones. The alcohols were obtained in 85–99% yield and 90–99% enantioselectivity with
Mechanochemical Enzymatic Kinetic Resolution of Secondary Alcohols under Ball-Milling Conditions
作者:José G. Hernández、Marcus Frings、Carsten Bolm
DOI:10.1002/cctc.201600455
日期:2016.5.20
Surprisingly, mechanochemical enzymatic transformations have only scarcely been studied until now. Here, we demonstrate the use of lipase B from Candida antarctica (CALB) in acylative kineticresolutions of secondaryalcohols in mixer and planetary mills. Despite the mechanical stress caused by the high‐speed ball milling, the biocatalyst proved highly effective, stable, and, in part, recyclable under the
Kinetic resolution of secondary alcohols with Burkholderia cepacia lipase immobilized on a biodegradable ternary blend polymer matrix as a highly efficient and heterogeneous recyclable biocatalyst
作者:Ganesh V. More、Kirtikumar C. Badgujar、Bhalchandra M. Bhanage
DOI:10.1039/c4ra14478c
日期:——
The present work reports a highly efficient and biocatalytic heterogeneous protocol for kinetic resolution (KR) of racemic secondary alcohols with vinyl acetate as an acyldonor, using the biocatalyst Burkholderia cepacia lipase (BCL) immobilized on a biodegradable ternary blend support through polylactic acid (PLA)/polyvinyl alcohol (PVA)/chitosan (CHI); (PLA/PVA/CHI–BCL). The KR reaction with various
Increased Enantioselectivity and Remarkable Acceleration of Lipase-Catalyzed Transesterification by Using an Imidazolium PEG–Alkyl Sulfate Ionic Liquid
types of imidazolium salt ionicliquids were prepared derived from poly(oxyethylene)alkyl sulfate and used as an additive or coating material for lipase-catalyzedtransesterification in an organic solvent. A remarkably increasedenantioselectivity was obtained when the salt was added at 3-10 mol % versus substrate in the Burkholderia cepacia lipase (lipase PS-C)-catalyzed transesterification of 1-phenylethanol