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Organocatalytic Access to Enantioenriched Spirooxindole-Based 4-Methyleneazetidines.

ABSTRACT: This work describes the synthesis of enantioenriched spiro compounds, incorporating the azetidine and the oxindole motifs. The preparation relies on a formal [2 + 2] annulation reaction of isatin-derived N-tert-butylsulfonyl ketimines with allenoates. The asymmetric induction is secured by an organocatalytic strategy, exploiting a bifunctional cinchona-type ?-isocupridine-based catalyst. Some post-transformation products, including unexpected spiropyrroline and 3,3-disubstituted oxindole derivatives, are also presented.

SUBMITTER: Rainoldi G

PROVIDER: S-EPMC6150293 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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Organocatalytic Access to Enantioenriched Spirooxindole-Based 4-Methyleneazetidines.

Rainoldi Giulia G Faltracco Matteo M Spatti Claudia C Silvani Alessandra A Lesma Giordano G

Molecules (Basel, Switzerland) 20171121 11

This work describes the synthesis of enantioenriched spiro compounds, incorporating the azetidine and the oxindole motifs. The preparation relies on a formal [2 + 2] annulation reaction of isatin-derived N-tert-butylsulfonyl ketimines with allenoates. The asymmetric induction is secured by an organocatalytic strategy, exploiting a bifunctional cinchona-type β-isocupridine-based catalyst. Some post-transformation products, including unexpected spiropyrroline and 3,3-disubstituted ox ...[more]

PMID: 29160827

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