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Nickel/bis(oxazoline)-catalyzed asymmetric Kumada reactions of alkyl electrophiles: cross-couplings of racemic alpha-bromoketones.

ABSTRACT: The first asymmetric Kumada reactions of alkyl electrophiles are described, specifically, cross-couplings of racemic alpha-bromoketones with aryl Grignard reagents. Several features of this investigation are of interest. First, the couplings proceed at remarkably low temperature (-40 or -60 degrees C), which enables the asymmetric synthesis of racemization-prone alpha-arylketones. Second, dialkyl ketones undergo enantioselective coupling in good ee and yield. Third, readily available bis(oxazolines) are shown for the first time to be effective ligands for cross-couplings of alkyl electrophiles, thereby opening the door to new opportunities in asymmetric catalysis.

SUBMITTER: Lou S

PROVIDER: S-EPMC2814537 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature

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Nickel/bis(oxazoline)-catalyzed asymmetric Kumada reactions of alkyl electrophiles: cross-couplings of racemic alpha-bromoketones.

Lou Sha S Fu Gregory C GC

Journal of the American Chemical Society 20100201 4

The first asymmetric Kumada reactions of alkyl electrophiles are described, specifically, cross-couplings of racemic alpha-bromoketones with aryl Grignard reagents. Several features of this investigation are of interest. First, the couplings proceed at remarkably low temperature (-40 or -60 degrees C), which enables the asymmetric synthesis of racemization-prone alpha-arylketones. Second, dialkyl ketones undergo enantioselective coupling in good ee and yield. Third, readily available bis(oxazoli ...[more]

PMID: 20050651

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