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Asymmetric ?-Chlorination of ?-Keto Esters Using Hypervalent Iodine-Based Cl-Transfer Reagents in Combination with Cinchona Alkaloid Catalysts.

ABSTRACT: We herein report an unprecedented strategy for the asymmetric ?-chlorination of ?-keto esters with hypervalent iodine-based Cl-transfer reagents using simple Cinchona alkaloid catalysts. Our investigations support an ?-chlorination mechanism where the Cinchona species serves as a nucleophilic catalyst by reacting with the chlorinating agent to generate a chiral electrophilic Cl-transfer reagent in situ. Using at least 20 mol-% of the alkaloid catalyst allows for good yields and enantioselectivities for a variety of different ?-keto esters under operationally simple conditions.

SUBMITTER: Stockhammer L

PROVIDER: S-EPMC7821243 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Asymmetric α-Chlorination of β-Keto Esters Using Hypervalent Iodine-Based Cl-Transfer Reagents in Combination with Cinchona Alkaloid Catalysts.

Stockhammer Lotte L Schörgenhumer Johannes J Mairhofer Christopher C Waser Mario M

European journal of organic chemistry 20200925 1

We herein report an unprecedented strategy for the asymmetric α-chlorination of β-keto esters with hypervalent iodine-based Cl-transfer reagents using simple Cinchona alkaloid catalysts. Our investigations support an α-chlorination mechanism where the Cinchona species serves as a nucleophilic catalyst by reacting with the chlorinating agent to generate a chiral electrophilic Cl-transfer reagent in situ. Using at least 20 mol-% of the alkaloid catalyst allows for good yields and enantioselectivit ...[more]

PMID: 33519300

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