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Chiral Bronsted acid catalyzed enantioselective synthesis of anti-homopropargyl alcohols via kinetic resolution-aldehyde allenylboration using racemic allenylboronates.

ABSTRACT: A chiral phosphoric acid catalyzed kinetic resolution/allenylboration of racemic allenylboronates with aldehydes is described. Allenylboration of aldehydes with 2.8 equiv of allenylboronate (±)-1 in the presence of 10 mol % of catalyst (R)-2 provided anti-homopropargyl alcohols 3 in 83-95% yield with 9:1 to 20:1 diastereoselectivity and 73-95% ee. The catalyst enables the kinetic resolution of the racemic allenylboronate (±)-1 to set the methyl stereocenter and biases the facial attack of the aldehyde to set the stereochemistry of the hydroxyl group in 3.

SUBMITTER: Tsai AS

PROVIDER: S-EPMC3640598 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

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Chiral Brønsted acid catalyzed enantioselective synthesis of anti-homopropargyl alcohols via kinetic resolution-aldehyde allenylboration using racemic allenylboronates.

Tsai Andy S AS Chen Ming M Roush William R WR

Organic letters 20130313 7

A chiral phosphoric acid catalyzed kinetic resolution/allenylboration of racemic allenylboronates with aldehydes is described. Allenylboration of aldehydes with 2.8 equiv of allenylboronate (±)-1 in the presence of 10 mol % of catalyst (R)-2 provided anti-homopropargyl alcohols 3 in 83-95% yield with 9:1 to 20:1 diastereoselectivity and 73-95% ee. The catalyst enables the kinetic resolution of the racemic allenylboronate (±)-1 to set the methyl stereocenter and biases the facial attack of the al ...[more]

PMID: 23484801

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