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Palladium-catalyzed asymmetric allylic alpha-alkylation of acyclic ketones.

ABSTRACT: The first example of Pd-catalyzed asymmetric allyl alkylation of the conformationally nonrigid acyclic ketone enolates is reported with excellent yields, regioselectivity, and enantioselectivity. The double bond geometry of the allyl enol carbonates affects its reactivity, selectivity, as well as the absolute configuration of the products. An opposite enantioselectivity from what is predicted by a direct attack of the enolate on the allyl moiety of the pi-ally-Pd complex was observed. An alternative mechanism was proposed, which involves an inner sphere process of coordination of the enolate to Pd followed by reductive elimination.

SUBMITTER: Trost BM

PROVIDER: S-EPMC2533158 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature

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Palladium-catalyzed asymmetric allylic alpha-alkylation of acyclic ketones.

Trost Barry M BM Xu Jiayi J

Journal of the American Chemical Society 20051201 49

The first example of Pd-catalyzed asymmetric allyl alkylation of the conformationally nonrigid acyclic ketone enolates is reported with excellent yields, regioselectivity, and enantioselectivity. The double bond geometry of the allyl enol carbonates affects its reactivity, selectivity, as well as the absolute configuration of the products. An opposite enantioselectivity from what is predicted by a direct attack of the enolate on the allyl moiety of the pi-ally-Pd complex was observed. An alterna ...[more]

PMID: 16332054

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