Flavins asymmetric sulfoxidation

Ghiral flavins have been used to obtain an asymmetric sulfoxidation with H2O2 as the oxidant [45a, 52]. Flavin 27, with planar chirality, was used to oxidize different aryl methyl sulfides with 35% H2O2. The hydrogen peroxide was added slowly over 5 days at —20°C to the substrate and the catalyst. The best result was obtained with the p-tolyl derivative, which gave 65% ee (Eq. (8.12)). 

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