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Palladium-catalyzed enantioselective C-3 allylation of 3-substituted-1H-indoles using trialkylboranes.

ABSTRACT: We have developed a new enantioselective C-3 allylation of 3-substituted indoles using allyl alcohol and trialkylboranes. Asymmetric syntheses of 3,3-disubstituted indolines and indolenines in enantiomeric excesses up to 90% have been achieved using the bulky borane 9-BBN-C6H13 as the promoter of the reaction. The dependence of the selectivity on the nature of the borane suggests that the boron reagent has a role beyond promoting ionization of the allyl alcohol. A protocol for oxidation of indolenines to oxindoles has also been developed and led to a formal synthesis of (-)-phenserine.

SUBMITTER: Trost BM

PROVIDER: S-EPMC2516200 | biostudies-literature | 2006 May

REPOSITORIES: biostudies-literature

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Palladium-catalyzed enantioselective C-3 allylation of 3-substituted-1H-indoles using trialkylboranes.

Trost Barry M BM Quancard Jean J

Journal of the American Chemical Society 20060501 19

We have developed a new enantioselective C-3 allylation of 3-substituted indoles using allyl alcohol and trialkylboranes. Asymmetric syntheses of 3,3-disubstituted indolines and indolenines in enantiomeric excesses up to 90% have been achieved using the bulky borane 9-BBN-C6H13 as the promoter of the reaction. The dependence of the selectivity on the nature of the borane suggests that the boron reagent has a role beyond promoting ionization of the allyl alcohol. A protocol for oxidation of indol ...[more]

PMID: 16683785

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