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Application of a new chiral phosphepine to the catalytic asymmetric synthesis of highly functionalized cyclopentenes that bear an array of heteroatom-substituted quaternary stereocenters.

ABSTRACT: Through the design and synthesis of a new chiral phosphepine, the first catalytic asymmetric method for the [3 + 2] cycloaddition of allenes with olefins has been developed that generates cyclopentenes that bear nitrogen-, phosphorus-, oxygen-, and sulfur-substituted quaternary stereocenters. A wide array of racemic ?-substituted allenes can be employed in this stereoconvergent process, which occurs with good enantioselectivity, diastereoselectivity, regioselectivity, and yield. Mechanistic studies, including a unique observation of a (modest) kinetic resolution of a racemic allene, are consistent with addition of the phosphepine to the allene being the turnover-limiting step of the catalytic cycle.

SUBMITTER: Fujiwara Y

PROVIDER: S-EPMC3150361 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature

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Application of a new chiral phosphepine to the catalytic asymmetric synthesis of highly functionalized cyclopentenes that bear an array of heteroatom-substituted quaternary stereocenters.

Fujiwara Yuji Y Fu Gregory C GC

Journal of the American Chemical Society 20110718 31

Through the design and synthesis of a new chiral phosphepine, the first catalytic asymmetric method for the [3 + 2] cycloaddition of allenes with olefins has been developed that generates cyclopentenes that bear nitrogen-, phosphorus-, oxygen-, and sulfur-substituted quaternary stereocenters. A wide array of racemic γ-substituted allenes can be employed in this stereoconvergent process, which occurs with good enantioselectivity, diastereoselectivity, regioselectivity, and yield. Mechanistic stud ...[more]

PMID: 21766794

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