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H-Bond Mediated Phase-Transfer Catalysis: Enantioselective Generating of Quaternary Stereogenic Centers in β-Keto
Patryk Niedbała1, Maciej Majdecki1, Piotr Grodek1
1Institute of Organic Chemistry PAS, 01-224 Warsaw, Poland.
Abstract:
In this work, we would like to present the development of a highly optimized method for generating the quaternary stereogenic centers in β-keto esters. This enantioselective phase-transfer alkylation catalyzed by hybrid Cinchona catalysts allows for the efficient generation of the optically active products with excellent enantioselectivity, using only 1 mol% of the catalyst. The vast majority of phase-transfer catalysts in asymmetric synthesis work by creating ionic pairs with the nucleophile-attacking anionic substrate. Therefore, it is a sensible approach to search for new methodologies capable of introducing functional groups into the precursor's structure, maintaining high yields and enantiomeric purity.
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