Enantioselective Vanadium‐Catalyzed Oxidation of 1,3‐Dithianes from Aldehydes and Ketones using β‐Amino Alcohol Derived Schiff Base Ligands |
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Authors: | Yinuo Wu Fei Mao Fanchao Meng Xingshu Li |
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Abstract: | The asymmetric vanadium‐catalyzed oxidation of 1,3‐dithianes from aldehydes and ketones by β‐amino alcohol‐derived Schiff base ligands with two stereogenic centers was investigated. Using aqueous hydrogen peroxide as the oxidant and the Schiff base 3b as a chiral ligand, a variety of 1,3‐dithianes derived from aldehydes were easily converted into the corresponding mono‐sulfoxides in good yields (81–88%) with excellent enantioselectivities (up to 99% ee). Additionally, 99% ee was obtained for the enantioselective vanadium‐catalyzed oxidation of the 1,3‐dithianes derived from ketones. We found a slight kinetic resolution when using a higher ratio of hydrogen peroxide during the oxidation of the aldehyde‐derived 1,3‐dithianes but not in the ketone‐derived 1,3‐dithianes. |
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Keywords: | asymmetric catalysis chiral sulfoxides 1,3‐dithianes Schiff base ligands vanadium |
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