Improved synthesis of Bn5CpRu(CO)(2)Cl and its application as racemization catalyst in preparative-scale metalloenzymatic dynamic kinetic resolution of 1-phenylethanol

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Mavrynsky D, Kanerva LT, Sillanpaa R, Leino R
Publisher: INT UNION PURE APPLIED CHEMISTRY
Publication year: 2011
Journal: Pure and Applied Chemistry
Journal acronym: PURE APPL CHEM
Volume number: 83
Issue number: 3
Start page: 479
End page: 487
Number of pages: 9
ISSN: 0033-4545


Abstract

An improved gram-scale synthesis of Bn5CpRu(CO)(2)Cl is reported based on heating of pentabenzylcyclopentadiene with Ru-3(CO)(12) at 160 degrees C under argon atmosphere in mesitylene followed by addition of chloroform, continued heating, and evaporation of the solvents. Subsequent washing of unreacted ligand precursor with hexane provided pure title compound in 77 % yield. In combination with Candida antarctica lipase B (CAL-B) (Novozym 435), this complex forms a highly active racemization catalyst for metallo enzymatic dynamic kinetic resolution (DKR) of secondary alcohols as demonstrated in the present work by converting 100 g of racemic 1-phenylethanol to (R)-1-phenylethanol in > 99 % ee and 93 % overall yield over two steps using 0.05 mol % loading of the metal catalyst and 1 mass % loading of immobilized enzyme. In addition, the synthesis and crystallographic characterization of the palladium congener Bn5CpPd(PPh3)Cl are briefly discussed.


Keywords

chemoenzymatic synthesis, cyclopentadienyl, dynamic kinetic resolution (DKR), Novozym, ruthenium

Last updated on 2019-15-12 at 04:39

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