Cinchona alkaloid-based chiral catalysts act as highly efficient multifunctional organocatalysts for the asymmetric conjugate addition of malonates to nitroolefins.
نویسندگان
چکیده
New pentaerythritol tetrabromide-based chiral quaternary ammonium salts acting as organocatalysts (7a and 7b) have been prepared and used as organocatalysts for enantioselective Michael addition reactions between various nitroolefins and Michael donors (malonates) under mild reaction conditions, such as lower concentration of base and catalyst and room temperature, with very good chemical yields (up to 97%) and ee's (up to 99%).
منابع مشابه
Asymmetric Michael addition mediated by novel cinchona alkaloid-derived bifunctional catalysts containing sulfonamides.
Novel cinchona alkaloid-derived bifunctional organocatalysts containing sulfonamide groups were utilized to promote Michael addition of bicyclic alpha-substituted beta-ketoesters to nitroolefins. The desired Michael adducts with all-carbon quaternary centers were constructed in high yield and with excellent enantioselectivity, demonstrating the great potential of cinchona alkaloid-derived sulfo...
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ورودعنوان ژورنال:
- Organic & biomolecular chemistry
دوره 13 40 شماره
صفحات -
تاریخ انتشار 2015