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P(NMe2)3-Mediated Umpolung Alkylation and Nonylidic Olefination of ?-Keto Esters.

ABSTRACT: A commercial phosphorus-based reagent (P(NMe2)3) mediates umpolung alkylation of methyl aroylformates with benzylic and allylic bromides, leading to either Barbier-type addition or ylide-free olefination products upon workup. The reaction sequence is initiated by a two-electron redox addition of the tricoordinate phosphorus reagent with an ?-keto ester compound (Kukhtin-Ramirez addition). A mechanistic rationale is offered for the chemoselectivity upon which the success of this nonmetal mediated C-C bond forming strategy is based.

SUBMITTER: Wang SR

PROVIDER: S-EPMC4769642 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

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P(NMe2)3-Mediated Umpolung Alkylation and Nonylidic Olefination of α-Keto Esters.

Wang Sunewang Rixin SR Radosevich Alexander T AT

Organic letters 20150715 15

A commercial phosphorus-based reagent (P(NMe2)3) mediates umpolung alkylation of methyl aroylformates with benzylic and allylic bromides, leading to either Barbier-type addition or ylide-free olefination products upon workup. The reaction sequence is initiated by a two-electron redox addition of the tricoordinate phosphorus reagent with an α-keto ester compound (Kukhtin-Ramirez addition). A mechanistic rationale is offered for the chemoselectivity upon which the success of this nonmetal mediated ...[more]

PMID: 26176378

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