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Syntheses of Highly Functionalized Spirocyclohexenes by Formal [4+2] Annulation of Arylidene Azlactones with Allenoates.

ABSTRACT: A straightforward phosphine-catalyzed formal [4+2] annulation between α-branched allenoates and arylidene azlactones has been developed to access highly functionalized spirocyclohexenes. This cyclization favors the γ-addition of the phosphine-activated allenoates over a β'-addition pathway. Detailed computational studies support the proposed mechanism and provide a reasonable explanation for the observed regioselectivity and the noted effect of the catalyst.

SUBMITTER: Eitzinger A

PROVIDER: S-EPMC6114148 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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Syntheses of Highly Functionalized Spirocyclohexenes by Formal [4+2] Annulation of Arylidene Azlactones with Allenoates.

Eitzinger Andreas A Zielke Katharina K Widhalm Michael M Robiette Raphaël R Waser Mario M

Asian journal of organic chemistry 20180504 8

A straightforward phosphine-catalyzed formal [4+2] annulation between α-branched allenoates and arylidene azlactones has been developed to access highly functionalized spirocyclohexenes. This cyclization favors the γ-addition of the phosphine-activated allenoates over a β'-addition pathway. Detailed computational studies support the proposed mechanism and provide a reasonable explanation for the observed regioselectivity and the noted effect of the catalyst. ...[more]

PMID: 30175031

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