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Dynamic kinetic asymmetric cross-benzoin additions of ?-stereogenic ?-keto esters.

ABSTRACT: The dynamic kinetic resolution of ?-halo ?-keto esters via an asymmetric cross-benzoin reaction is described. A chiral N-heterocyclic carbene catalyzes the umpolung addition of aldehydes to racemic ?-keto esters. The resulting fully substituted ?-halo glycolic ester products are obtained with high levels of enantio- and diastereocontrol. The high chemoselectivity observed is a result of greater electrophilicity of the ?-keto ester toward the Breslow intermediate. The reaction products are shown to undergo highly diastereoselective substrate-controlled reduction to give highly functionalized stereotriads.

SUBMITTER: Goodman CG

PROVIDER: S-EPMC4210110 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature

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Dynamic kinetic asymmetric cross-benzoin additions of β-stereogenic α-keto esters.

Goodman C Guy CG Johnson Jeffrey S JS

Journal of the American Chemical Society 20141009 42

The dynamic kinetic resolution of β-halo α-keto esters via an asymmetric cross-benzoin reaction is described. A chiral N-heterocyclic carbene catalyzes the umpolung addition of aldehydes to racemic α-keto esters. The resulting fully substituted β-halo glycolic ester products are obtained with high levels of enantio- and diastereocontrol. The high chemoselectivity observed is a result of greater electrophilicity of the α-keto ester toward the Breslow intermediate. The reaction products are shown ...[more]

PMID: 25299730

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