Optimization of and Mechanistic Considerations for the Enantioselective Dihydroxylation of Styrene Catalyzed by Osmate-Laccase-Poly(2-Methyloxazoline) in Organic Solvents
ChemCatChem 2016, 8, 593-599, 10.1002/cctc.201501083
The Sharpless dihydroxylation of styrene with the artificial metalloenzyme osmate‐laccase‐poly(2‐methyloxazoline) was investigated to find reaction conditions that allow this unique catalyst to reveal its full potential. After changing the co‐oxidizing agent to tert‐butyl hydroperoxide and optimizing the osmate/enzyme ratio, the turnover frequency and the turnover number could be increased by an order of magnitude, showing that the catalyst can compete with classical organometallic catalysts. Varying the metal in the active center showed that osmate is by far the most active catalytic center, but the reaction can also be realized with permanganate and iron(II) salts.
Polymer Enzyme Conjugates as Chiral Ligands for Sharpless Dihydroxylation of Alkenes in Organic Solvents
ChemBioChem 2015, 16, 83-90, 10.1002/cbic.201402339
Count Os in: We report organosoluble artificial metalloenzymes, generated from poly(2‐methyl‐oxazoline) enzyme conjugates and osmate as a promising new catalytic system for the dihydroxylation of alkenes in organic media.
Metal: OsLigand type: Amino acidHost protein: LaccaseAnchoring strategy: Metal substitutionOptimization: ChemicalReaction: DihydroxylationMax TON: 80ee: 98PDB: ---Notes: ---