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Stereocontrol in N-directed hydroboration: synthesis of amino alcohols related to the piperidine alkaloids.

ABSTRACT: Treatment of 2-(2'-alkenyl)-piperidine boranes with iodine or triflic acid induces internal hydroboration with high regiocontrol, even with a terminal alkene (R = H). Good stereocontrol is possible for the N-benzyl substrates. Comparisons with acyclic model structures show that the source of regiocontrol with the terminal alkene is due to a steric effect of the axial piperidine C(3,5) hydrogens that destabilize the competing bridged bicyclic transition state.

SUBMITTER: Wang G

PROVIDER: S-EPMC2765555 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature

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Stereocontrol in N-directed hydroboration: synthesis of amino alcohols related to the piperidine alkaloids.

Wang Guoqiang G Vedejs Edwin E

Organic letters 20090301 5

Treatment of 2-(2'-alkenyl)-piperidine boranes with iodine or triflic acid induces internal hydroboration with high regiocontrol, even with a terminal alkene (R = H). Good stereocontrol is possible for the N-benzyl substrates. Comparisons with acyclic model structures show that the source of regiocontrol with the terminal alkene is due to a steric effect of the axial piperidine C(3,5) hydrogens that destabilize the competing bridged bicyclic transition state. ...[more]

PMID: 19182927

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