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Selection between Diastereomeric Kinetic vs Thermodynamic Carbonyl Binding Modes Enables Enantioselective Iridium-Catalyzed anti-(?-Aryl)allylation of Aqueous Fluoral Hydrate and Difluoroacetaldehyde Ethyl Hemiacetal.

ABSTRACT: Enantioselectivity increases with increasing carbonyl electrophilicity in 2-propanol-mediated reductive couplings of aldehydes with branched aryl-substituted allylic acetates to form products of carbonyl anti-(?-aryl)allylation. This unusual phenomenon is caused by aldehyde coordination to diastereomeric kinetic vs thermodynamic carbonyl binding sites that deliver enantiomeric products. Exploiting this effect, anti-diastereo- and enantioselective (?-aryl)allylations of fluoral hydrate and difluoroacetaldehyde ethyl hemiacetal were developed.

SUBMITTER: Cabrera JM

PROVIDER: S-EPMC6206506 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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Selection between Diastereomeric Kinetic vs Thermodynamic Carbonyl Binding Modes Enables Enantioselective Iridium-Catalyzed anti-(α-Aryl)allylation of Aqueous Fluoral Hydrate and Difluoroacetaldehyde Ethyl Hemiacetal.

Cabrera James M JM Tauber Johannes J Zhang Wandi W Xiang Ming M Krische Michael J MJ

Journal of the American Chemical Society 20180718 30

Enantioselectivity increases with increasing carbonyl electrophilicity in 2-propanol-mediated reductive couplings of aldehydes with branched aryl-substituted allylic acetates to form products of carbonyl anti-(α-aryl)allylation. This unusual phenomenon is caused by aldehyde coordination to diastereomeric kinetic vs thermodynamic carbonyl binding sites that deliver enantiomeric products. Exploiting this effect, anti-diastereo- and enantioselective (α-aryl)allylations of fluoral hydrate and difluo ...[more]

PMID: 30020777

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